Die doppelte Kontingenz von Elfmeterschüssen.
Transcription
Die doppelte Kontingenz von Elfmeterschüssen.
Die doppelte Kontingenz von Elfmeterschüssen. Eine empirische Analyse Von Roger Berger und Rupert Hammer! Zusammenfassung: Beim Elfmeterschuss bilden Torwart und Schütze zeitgleich und wechselseitig Erwartungen zur Sprung- bzw. Schussrichtung ihres Gegners und handeln entsprechend. Strafstöße sind damit ein ideales Beispiel fUr doppelte Kontingenz und eignen sich auf Grund ihres standardisierten Ablaufs für einen empirisch fundierten Vergleich der einschlägigen Ansätze Parsons, Luhmanns und der Spieltheorie. Dieser Vergleich zeigt, dass sich nur aus der Spieltheorie empirisch gehaltvolle Aussagen zu Handlungsmustern der Spieler ableiten lassen. Diese folgen aus der Minimax-Lösung und besagen, dass die Spieler ihre Entscheidungen mit vorhersagbaren Wahrscheinlichkeiten randomisieren. Parsons Ansatz dagegen ist nicht auf die Elfmetersituation anwendbar. Da die Interessen der Spieler hier vollständig komplementär sind, können sich keine geteilten stabilen Muster bilden, an denen die Akteure ihre Seitenwahl ausrichten. Denn jedes Muster würde vom Gegner sofort zum eigenen Vorteil unterlaufen werden. Aus Luhmanns Ansatz folgt, dass die Spieler beim Elfmeter handlungsunfähig sind, weil sie den infiniten Regress von Erwartungen wegen der Gleichzeitigkeit der Entscheidungen und der fehlenden Möglichkeit kommunikativer Aushandlungsprozesse nicht durchbrechen können. Für die empirische Analyse benutzen wir einen Datensatz, der alle 1043 Elfmeterschiisse aus elf Spielzeiten der Bundesliga umfasst. Sie bestätigt weitgehend die spieltheoretischen Hypothesen. Die beobachteten professionellen Fußballspieler lösen die doppelte Kontingenz »Elfmeterschuss« wie vorhergesagt. Dies trifft insbesondere auf die Torhüter zu, die im spieltheoretischen Sinne fast optimal handeln. 1. Einleitung Ana7sen rund um das Fußballspiel erfreuen sich in der Soziologie einer gewissen Beliebtheit. Allerdings finden sich - abgesehen von dem bekannten Artikel von Esser (1991) - keine Arbeiten, die sich mit einzelnen Spielsituationen befassen. Dies ist insofern erstaunlich, als soziale Interaktion bei Spielen wie Fußball quasi wie im Reagenzglas stattfindet. Die Interaktionen sind real und es steht (fast) immer buchstäblich etwas auf dem Spiel. Gleichzeitig ist die soziale Situation örtlich und zeitlich eingeschränkt und gut beobachtbar. Auch die Zahl der Akteure und ihre Handlungsalternativen sind vorgegeben, was die theoretische und empirische Analyse vereinfacht. Dies ist bei der im Folgenden betrachteten sozialen Interaktion - der Elfmetersituation ebenfalls der Fall. Der Schütze versucht dabei, den Ball aus einer Distanz von 11 Metern mit einem Schuss im Tor unterzubringen. 3 Der Torhüter, auf der Torlinie stehend, probiert eben dies zu verhindern. Beide Spieler stehen dabei vor demselben Problem: Auf welche Seite des 1) Roger Berger ist Stipendiat des Schweizerischen Nationalfonds (Stipendium Nr. PA-108952 I 1) an der Universität Leipzig. Rupert Hammer ist Absolvent des Diplomstudiengangs am Institut für Soziologie der LMU München. Wir danken Thomas Voss und einem anonymen Gutachter für Verbesserungsvorschläge. Holger Rablfs und Jöm Wendland von der IMP AG München danken wir für die kostenlose Bereitstellung des verwendeten Datenmaterials. Angela Fabry danken wir für die sprachliche Überarbeitung. Für alle verbleibenden Fehler sind die Autoren verantwortlich. 2) Vgl. exemplarisch die Internetseite für sozialwissenschaftliche Fußballforschung (www.ruhr-uni-bochum.de/fussball) oder Kalter (1999). 3) Ein Elfmeter wird vom Schiedsrichter ausgesprochen, wenn ein Spieler im eigenen Sechzehnmeterraum eine von zehn möglichen Regelübertretungen - normalerweise Foul- oder Handspiel- begeht. Soziale Welt 58 (2007), S. 397 - 418 398 Roger Berger und Rupert Hammer Tors soll der Ball geschossen werden bzw. der Torhüter springen. Die Schussgeschwindigkeit des Balles und die Ausmaße des Tors (7,11 m breit und 2,44 m hoch) machen es nämlich zwingend erforderlich, dass der Torhüter sich für eine Ecke entscheidet, bevor er eindeutig sehen kann, wohin der Ball fliegt. Der Schütze wiederum weiß, dass der Torwart nicht vor dem Moment der Schussabgabe in eine Ecke springen wird, da er sich sonst sämtlicher Abwehrchancen berauben würde. Ein Schuss in die jeweils andere Ecke würde dann den sicheren Torerfolg bedeuten. Die Elfmetersituation erfordert deswegen eine simultane Entscheidung der beteiligten Spieler und das Ergebnis - Tor oder nicht - hängt immer von der Entscheidung beider Akteure ab. Bei einern erfolgreichen Torschuss würde sich der Torhüter im Nachhinein wünschen, in die andere Ecke gesprungen zu sein, ebenso wie der Schütze bei einern Misserfolg lieber die andere Ecke gewählt hätte, wenn er gewusst hätte, dass der Torwart sich in diese wirft. Das erzielte bzw. nicht erzielte Tor ist also ein emergentes soziales Phänomen, das von einem Akteur alleine nicht erzeugt werden kann, sondern sich erst aus der Interaktion ergibt. Die Elfmetersituation ist damit als soziologischer Untersuchungsgegenstand prädestiniert. Dies gilt umso mehr, als die Struktur dieser Interaktion ein idealtypisches Beispiel für eine Situation doppelter Kontingenz ist. Denn Ego, das in seinen Aktionen prinzipiell frei ist, trifft auf Alter, für den das ebenfalls gilt und beide Akteure wissen, dass beide dies wissen, etc. Die soziologische Bedeutung dieser Interaktionsstruktur zeigt sich auch daran, dass sich verschiedene theoretische Ansätze prominent mit dieser Frage beschäftigen. Folgt man Ganssmann (2006), so sind dies insbesondere die Spieltheorie und die Ansätze von Parsons und Luhmann. Diese werden in diesem Aufsatz einander gegenilbergestellt und daraufhin untersucht, ob und wenn ja, welche stabilen Verhaltensmuster der beiden Spieler sie für Strafstöße (nämlich die in der ersten Bundesliga ausgeführten) vorhersagen, und ob sich diese theoretisch fundierten Prognosen empirisch bestätigen lassen. Dazu werden im nächsten Abschnitt 2 die fußballerischen Grundlagen des Problems dargelegt. In Abschnitt 3 werden erst die aus der Spieltheorie folgenden Vorhersagen zur Elfmetersituation entwickelt. Anschließend wird analog für die Ansätze von Parsons und Luhmann verfahren. Im 4. Abschnitt wird der Stand der empirischen Forschung berichtet und im 5. die theoretischen Vorhersagen an einem Datensatz überprüft, der alle Elfmetersituationen der ersten Bundesliga der Spielzeiten von 1992 bis 2004 umfasst. Im letzen Abschnitt werden die Ergebnisse diskutiert. 2. Die Interaktion zwischen Schütze und Torwart Im Folgenden werden die fußballerischen Grundlagen der Strafstoßsituation dargestellt. Mittels der zentralen Regeln der zuständigen Organisation FIFA kann der Ablauf beschrieben werden: »Der Ball wird auf die Strafstossmarke [11 m vom Mittelpunkt der Torlinie zwischen den Pfosten und gleich weit von beiden Pfosten entfernt] gelegt. Der ausführende Spieler muss klar identifiziert sein. Der Torwart der verteidigenden Mannschaft muss mit Blick zum Schützen auf seiner Torlinie zwischen den Pfosten bleiben, bis der Ball mit dem Fuß gestossen ist. Der ausführende Spieler muss den Ball mit dem Fuss nach vorne stossen.« (FIFA 2005, Auszug Regel 14). Obschon dies nicht zwingend vorgeschrieben ist, wird der Ball vorn Elfmeterschützen direkt auf das Tor geschossen, da sich durch einen Pass auf einen Mitspieler kein Vorteil erzielen lässt. 4 4) Tatsächlich kommt ein Passspiel fast nie vor. Berühmt geworden ist allerdings ein Strafstoß von Cruyffund Dlsen von Ajax Amsterdam aus dem Jahre 1982, in dem sich die beiden Spieler vor dem (erfolgreichen) Torschuss sogar zweimal zupassten. Im letzten bekannten Beispiel gelang es 2005 Henry und Pires von Arsenal FC im Spiel gegen Manchester City allerdings nicht, ein Tor aus dem gepassten Strafstoß zu erzielen. Die doppelte Kontingenz von Elfmeterschüssen 399 Der Schütze kann nun relativ sicher sein, dass der Ball ins Tor geht, wenn er den Ball in eine vom Torwart möglichst entfernte Zone des Tors schießt. Dann führt in der Regel auch ein nicht mit maximaler Präzision und Wucht ausgeführter Schuss zum Tor. Dazu stehen dem Schützen nun zwei Optionen offen. Er kann den Ball nach links schießen, wenn er erwartet, dass der Torwart nach rechts springt und vice versa. Der Torhüter ist umgekehrt ebenso gezwungen, sich »schon vor dem Anlauf des Schützen eine bestimmte Ecke auszuwählen. Sobald der Elfmeterschütze den Ball berührt, springt er in die von ihm spekulierte Ecke. Wird der Ball in die andere Ecke geschossen, ist der Torerfolg des Gegners nicht mehr zu verhindern. Wird er in die von ihm ausgewählte Ecke geschossen, erhöhen sich seine Chancen, den Ball zu halten ... [, d]enn so fällt die Reaktionszeit von 0,25 s weg« (Johanni / Tschachner 2005, S. 28). Würde der Torwart erst nach der Schussabgabe springen, könnte er einen ausreichend hart getretenen BallS nie halten, da dazu die menschliche Reaktionszeit und Sprungkraft nicht ausreicht (vgl. Johanni / Tschachner 2005). Der Torhüter muss also eine Erwartung über die vorn Schützen gewählte Ecke bilden. Das Problem besteht nun offensichtlich darin, dass der hier betrachtete professionelle Elfmeterschütze seine Erwartungen wiederum entsprechend anpassen wird, worauf der Torwart wiederum die andere Seite wählen wird usw. usf. Da die beiden Spieler aber nun beim Elfmeterschuss offensichtlich nicht wie Buridans Esel stehen bleiben, stellt sich die Frage, wie eine Auflösung dieses Zirkels sich potentiell gegenseitig blockierender Erwartungen, wie er typisch ist für eine doppelte Kontingenz, aus theoretischer Sicht aussehen kann. 3. Theoretische Lösungsmöglichkeiten der doppelten Kontingenz beim Elfmeterschuss Die theoretische Darstellung beginnt mit der spieltheoretischen Analyse. Anschließend erfolgt die Darstellung der entsprechenden Ansätze von Parsons und Luhmann. 3.1 Elfmeterschüsse aus spieltheoretischer Sicht Die Spieltheorie ist der Zweig der Theorie rationalen Handels, welcher sich mit SituationeI1 strategischer Interdependenz befasst. Die Annahmen, von denen die Theorie rationalen Handelns ausgeht, gelten daher auch für die Spieltheorie (und einige mehr dazu). Hier wird allerdings darauf verzichtet, alle diese Annahmen darzulegen. Stattdessen wird nur auf die für die: vorgenommene Analyse entscheidenden Prämissen eingegangen, welche im Folgender aufgeführt werden. 6 Die beiden Spieler haben eine stabile Präferenzordnung. Jedem mögli chen Ausgang des Spiels ist für jeden Spieler ein bestimmter Nutzen zugeordnet, der die Präferenzordnung des Spielers vollständig abbildet.? Für die hier vorgenommene Analyse muss dieser Nutzen außerdem kardinal sein (vgl. Varian 1992). Beide Spieler kennen dil Struktur des Spiels und insbesondere ihre eigenen Auszahlungen, sowie die Payoffs des an deren Spielers. Zudem wissen beide Spieler, dass beide Spieler dies wissen, dass beide Spie ler dies wissen, etc. Diese letzte Annahme wird als »common knowledge« bezeichnet. AU . diese Bedingungen sind beim Elfmeterschuss erfüllt. Das Spiel hat zwei unterschiedlich 5) Die größere Herausforderung für den Schützen stellt dabei die Schussgenauigkeit dar. Selbst schlecl te Amateurspieler können dem Ball die erforderliche Geschwindigkeit geben. Professionelle Spiel( können den Ball beim Strafstoß mit einer Geschwindigkeit von mehr als 27 mls schießen. Dem TOJ wart bleibt damit kaum eine halbe Sekunde, um den Ball zu erreichen, bevor er im Tor liegt (Joham I Tschachner 2005, S. 26). 6) Eine aktuelle Einführung in die Theorie rationalen Verhaltens geben z.B. Diekmann I Voss (2004) 7) Dabei müssen diese Präferenzen nicht zwingend eigennutzorientiert sein. Die - hier selbstverstän( liche - Annahme egoistischer Präferenzen macht allerdings die unabdingbare »common knov ledge«-Annahme (siehe unten) plausibler. Roger Berger und Rupert Hammer 400 Ausgänge: »Tor« oder »kein Tor«. Dies ist beiden Spielern bekannt. Ebenso bekannt ist der kardinale Nutzen, den die beiden Ausgänge für beide Spieler haben und der genau ein Tor (erzielt oder verhindert) beträgt. Und offensichtlich wissen auch beide Spieler, dass dies beide Spieler wissen, usw. usf. Das Elfmeterschießen selbst ist, in spieltheoretischen Termini ausgedrückt, ein einfach gespieltes Nullsummenspiel mit vollständiger, aber nicht perfekter Information und simultanen Zügen. Bereits 1928 hat von Neumann mit seiner »Theorie der Gesellschaftsspiele« alle formalen Grundlagen für die hier benötigte Analyse gelegt. 8 Grafisch wird das Spiel am einfachsten in strategischer Form dargestellt. In der Literatur wird es in Anlehnung an ein Kinderspiel als »matching pennies« bezeichnet. Abbildung 1: Auszahlungsmatrix des Elfmeterschusses, mit den beiden Handlungsoptionen »Links« und »Rechts« Torhüter 4U1 Spieler. 9 Keiner der beiden Spieler kann seinen erwarteten Nutzen erhöhen, indem er von dieser Entscheidung abweicht, solange der andere Spieler ebenfalls nicht davon abweicht. Die theoretische Analyse könnte damit abgeschlossen werden. Eine zu prüfende Hypothese würde dann lauten, dass beide Seiten sowohl vom Schützen als auch vom Torwart gleich häufig gewählt werden. Für die empirische Überprüfung der Vorhersagen zum Spiel »matching pennies« wäre dies auch genügend. Aber beim Elfmeterschuss ergeben sich trotz seiner strukturellen Einfachheit doch einige zusätzliche Fragen: Beispielsweise besteht für den Schützen auch die Möglichkeit in die Mitte des Tores zu schießen, weshalb der Torwart in der Mitte des Tors stehen bleiben und einen derart geschossenen Ball mit Leichtigkeit abwehren könnte. Weiterhin ist bekannt, dass die Schützen ihren »starken« Fuß für den Schuss bevorzugen, wenn sie, wie beim Strafstoß, frei wählen können. Außerdem kann ein Strafstoß auch dann ins Tor gehen, wenn der Torwart in die richtige Ecke springt. Umgekehrt besteht auch die Möglichkeit, dass der Schuss an die Torumrandung oder gänzlich daneben geht, selbst dann, wenn der Torwart in die falsche Ecke gesprungen ist. Insgesamt erscheint daher eine verfeinerte Analyse sinnvoll: Fehlschüsse an die Torumrandung bzw. Treffer trotz richtiger Torwartentscheidung Links Rechts Links -1,1 1, -1 Rechts 1, -1 -1, 1 Schütze Uie doppelte Kontingenz von tJjmeterschüssen Die erste Zahl in jeder Zelle bezeichnet jeweils die Auszahlung des Schützen, die zweite diejenige des Torhüters. Die Lösung des Spiels ist nun diejenige Kombination der Strategien der beiden Spieler, von denen keiner abweichen will, solange der jeweils andere seine Wahl beibehält. Eine Strategie besteht dabei aus einer eindeutigen Anweisung, was an jedem Punkt, an den das Spiel kommen kann, zu tun ist. Die möglichen Handlungen sind nach links oder rechts zu schießen bzw. zu springen. Die Lösung ist ein gemischtes Nash-Gleichgewicht, d.h. eine Strategienkombination, die darin besteht, dass beide Spieler zwischen den beiden Handlungsmöglichkeiten »Links« und »Rechts« mischen. Die Strategien der beiden Spieler geben ihnen vor, aus welcher Wahrscheinlichkeitsverteilung sie ihre Handlung zufallig wählen sollen. Die Randomisierung geschieht dabei unter Einberechnung des Nutzens, den der Gegenspieler aus einer bestimmten Auszahlung bezieht. Die Wahrscheinlichkeiten für die eigene Entscheidung werden dann genau so gewählt, dass sie die eigene Auszahlung maximieren, also so, dass die Erfolgswahrscheinlichkeit für den Torschuss bzw. die Abwehr am größten ist. Dies geschieht unter der Annahme, dass der Gegner gleichfalls maximiert. D.h. das aus dieser simultanen Maximierung resultierende Nash-Gleichgewicht ist (immer) ein Gleichgewicht, sowohl in Erwartungen als auch in Handlungen (vgl. Varian 1992, S. 265). Es lässt sich intuitiv erahnen, dass die entsprechenden Wahrscheinlichkeiten bei der ModelIierung des Elfmeterschusses als »matching pennies« genau 0,5 für beide Seiten betragen (für eine formale Herleitung siehe verschiedene Lehrbücher, z.B. Dixit / Skeath 2004 für eine Illustration mit Sport). Der erwartete Nutzen beträgt damit Null für jeden der beiden 8) Die Ausführungen von Neumanns sind als so genanntes Minimax-Theorem in die Literatur eingegangen. Weil in dem Aufsatz theoretisch eine breitere Perspektive eingenommen wird, wird hier vom allgemeineren Konzept des Nash-Gleichgewichts ausgegangen. Für Nullsummenspiele fallen allerdings das Nash-Gleichgewicht und die Minimax-Lösung zusammen, so dass dieses Vorgehen keine theoretischen Auswirkungen hat. Im Spiel »matching pennies« sind die Auszahlungen vorgegeben und werden mit Sicherheit ausbezahlt, wenn eine bestimmte Strategienkombination auftritt. Beim Strafstoß ist dies nicht zwingend der Fall. So gilt ein Schuss genau in eine der oberen Torecken allgemein als unhaltbar. Allerdings ist bei dieser Entscheidung auch das Risiko recht groß, dass der Schuss neben das Tor oder an die Torumrandung geht. Dies kann berücksichtigt werden, indem für die deterministischen Auszahlungen [1, -1] aus dem Spiel »matching pennies« die Trefferwahrscheinlichkeiten [Qi' Pj ] eingesetzt werden, wie sie in Abbildung 2 dargestellt sind. (Die unterschiedlichen Wahrscheinlichkeiten für die linke und rechte Seite sowie die Mitte bzw. deren Gegenwahrscheinlichkeiten ergeben sich aus weiteren Überlegungen (siehe unten).) Die Wahrscheinlichkeiten entsprechen im Betrag gleichzeitig den erwarteten Payoffs kardinalen Nutzens von 1 (Tor). Schuss in die Mitte Schützen wählen in wenigen Fällen keine der beiden Seiten, sondern zielen in die Mitte. Noch seltener kommt es vor, dass der Torwart in der Erwartung eines solchen Schusses in der Mitte stehen bleibt. Im Gegensatz zu den Sprüngen auf die Seiten hat diese Strategie für den Torwart den Vorteil, dass der Ball fast sicher abgewehrt werden kann, wenn er tatsächlich in die Mitte kommt. Ebenso sicher resultiert aber ein Tor, wenn dies nicht geschieht und der Schuss auf eine der beiden Seiten geht. Da insbesondere die Schüsse in die Mitte empirisch nicht zu vernachlässigen sind, wird im Folgenden in Anlehnung an Chiappori et al. (2002) der Elfmeterschuss mit dem Strategienraum {Links, Mitte, Rechts} modelliert. Mit Palacios-Huerta (2003) ist es auch denkbar, den Strategienraum mit einem technischen Argument auf den Strategienraum {Links, Rechts} zu reduzieren. Dabei wird angenommen, dass Schüsse in die Mitte mit denselben Kosten verbunden sind wie diejenigen auf die rechte Seite (vom Torwart aus gesehen für Rechtsfüßer und vice versa, vgl. unten), weil sie mit derselben Schusstechnik ausgeführt werden. In diesem Fall werden die Schüsse in die Mitte zur rechten Seite gezählt. Bei der empirischen Analyse wird in einzelnen Fällen auf dieses Argument zurückgegriffen und es werden nur zwei Schussrichtungen betrachtet, wenn die Analyse ansonsten nicht sinnvoll durchführ- oder darstellbar ist. 9) Im Gegensatz zu dieser Gleichgewichtsauszahlung bedingt die Definition eines Nullsummenspiels nur, dass die erwartete Auszahlung des gesamten Spiels Null beträgt. 402 Roger Berger und Rupert Hammer Es muss betont werden, dass es sich bei der Frage, ob die Elfmetersituation mit zwei oder drei Strategien modelliert werden soll, um ein rein empirisches Problem handelt. Spieltheoretisch betrachtet ist nur entscheidend, dass die Spieler ihre Schuss- bzw. Sprungrichtungen derart mischen, dass für jeden Punkt des Tores die gleiche Treffer- bzw. Abwehrwahrscheinlichkeit besteht. Wenn entsprechend präzise Daten zur Verfügung stehen würden, könnte die empirische Analyse deshalb auch auf einen noch größeren Strategienraum ausgedehnt werden. Für die hier verwendeten Daten ist dies jedoch nicht sinnvoll. Die doppelte Kontingenz von Elfmeterschüssen mit »rechts« bezeichnet. Für mit dem linken Fuß schießende Schützen ist die natürliche Seite dagegen vom Torwart aus gesehen links. Diese wird dann ebenfalls mit »rechts« (weil natürliche Seite) bezeichnet (und vice versa). Dies ermöglicht es, alle Elfmetersituationen für Rechts- und Linksfüßer sowie für die Torhüter in einer einheitlichen Notation zu analysieren. Damit stellt sich das Spiel »Elfmeterschuss« wie folgt dar (vgl. Abb. 2): Abbildung 2: Matrixdarstellung des Elfmeterschusses, mit den Treffer- bzw. Abwehrwahrscheinlichkeitenfür die Handlungsalternativen »Links«, »Mitte« und »Rechts« Gleichheit des Spiels in jeder Spielsituation undfür beide Spieler bzw. Schussfüße Es ist denkbar, dass die Treffer- bzw. Abwehrwahrscheinlichkeit nicht bei jedem Strafstoß und bei jedem Spieler bzw. jeder Spielerkombination gleich ist. Möglicherweise sind z.B. die Schützen mehr unter Druck, wenn ihr Team im Rückstand liegt, wenn das Spiel fast zu Ende ist, so dass ein Tor wahrscheinlich das letzte im Spiel sein würde, oder wenn der Schütze ein Heimspiel hat. Weiterhin ist bekannt, dass die Schützen jeweils einen »starken« Fuß haben, mit dem sie besser schießen können als mit dem »schwachen« Fuß. Rechtsfüßer schießen aus anatomischen Gründen einfacher in die linke Ecke und Linksfüßer umgekehrt in die rechte Ecke. Auch hier ist denkbar, dass Linksfüßer z.B. eine höhere Trefferwahrscheinlichkeit haben als Rechtsfüßer, weil die Torhüter z.B. weniger Übung darin haben, die selteneren Schüsse von Linksfüßern abzuwehren. Allgemeiner ausgedrückt muss untersucht werden, ob die Kosten der beiden Spieler bei jedem Elfmeter in jeder Spielsituation gleich sind. IO Für das Spiel »matching pennies« ist dies tatsächlich so. Der kardinale Nettonutzen ist im Betrag genau 1. Sollte dies beim Elfmeterschuss nicht zutreffen, so würden die Auszahlungen bzw. Trefferwahrscheinlichkeiten für die Wahl der drei Handlungsoptionen dadurch verändert werden und damit auch die optimale Strategie. Dies bedeutet gleichzeitig, dass sich, je nachdem welche Annahmen über das tatsächlich gespielte Spiel zu Grunde gelegt werden, auch die resultierende Hypothesenmenge ändert. Aus Übersichtlichkeitsgründen wird diese Analyse hier nicht vollständig vorgeführt (siehe dafür Chiappori et al. 2002). Vielmehr wird hier ein Resultat der empirischen Analyse schon vorgezogen und nur diejenige Hypothesenmenge betrachtet, die zu den tatsächlich beobachteten empirischen Gegebenheiten passt. Dadurch wird nicht der Anwendungsbereich der spieltheoretischen Überlegungen eingeschränkt, sondern nur der für diese Anwendung empirisch testbare Bereich. Die theoretischen Überlegungen gelten unabhängig davon für jeden einzelnen Elfmeterschuss. Diese Einschränkungen sind allerdings nicht gravierend, da die Spielsituation des Elfmeters im verwendeten Datensatz in jeder Minute des Spiels und bei jedem Spielstand gleich ist. Für die Torhüter unterscheidet sich das Spiel nicht, egal ob sie einem Rechts- oder einem Linksfüßer gegenüber stehen. Allerdings unterscheidet sich die Trefferwahrscheinlichkeit für den Schützen in Abhängigkeit von seinem Schussfuß. Tatsächlich schießen Rechtsfüßer, wie vermutet, leichter in die linke Ecke und für Linksfüßer verhält es sich umgekehrt. In der Folge wird diese Seite als »natürliche« Seite bezeichnet (also bei Rechtsfüßern die linke und bei Linksfüßem die rechte). Da die Torhüter den Schussfuß der Schützen und demzufolge auch die natürliche Ecke kennen 11, kann jeder Strafstoß dadurch beschrieben werden, ob der Schütze in die natürliche Ecke schießt und der Torwart in die natürliche Ecke springt. In der Folge wird bei rechts schießenden Schützen die vom Torwart aus gesehen rechte Seite als natürliche Seite für Schützen und Torwart betrachtet und 10) Für den Nutzen gibt es hierzu keine Zweifel. Dieser ist im Betrag für beide Spieler genau gleich groß. 11) Der starke bzw. Schussfuß ist einfach am Anlauf des Schützen erkennbar (von links, um mit rechts zu schießen und umgekehrt). 403 Torhüter I Schütze Links Mitte Rechts Links PL, I-P L QL,I-QL QL,I-QL Mitte M,l-M 0, I M,I-M Rechts QR,I-QR QR,I-QR PR' I-PR Der erste Ausdruck in jeder Zelle bezeichnet jeweils die Wahrscheinlichkeit, dass der Strafstoß in einem Tor resultiert (die erwartete Auszahlung für den Schützen). Entsprechend gibt die Gegenwahrscheinlichkeit die erwartete Auszahlung für den Torwart an, dass kein Tor resultiert. Für die Reihenfolge der Torerfolgswahrscheinlichkeiten ergeben sich dadurch die aus den obigen Ausführungen unmittelbar einsichtigen Annahmen: 1. QR> PL 2. QR>M 3. QR ~ QL 4. QL -PL und und und QL>PR QL>M ~ QR-PR PR~PL Für den Schützen heißt dies: Die Wahrscheinlichkeit des Torerfolgs ist höher, wenn der Torwart in die falsche Ecke springt, als wenn dieser die richtige Ecke wählt (Annahme 1). Ein solcher Schuss in die entgegensetzte Ecke des Torwarts hat dabei eine höhere Trefferwahrscheinlichkeit, als wenn der Schütze in die Mitte schießt (Annahme 2). Wenn der Torwart in die falsche Ecke springt, ist die Chance, ein Tor zu erzielen, bei einem Schuss auf die natürliche Seite mindestens so groß wie oder größer als bei einem Schuss auf die unnatürliche Seite (Annahme 3). Das Risiko, dass der Torwart den Ball hält, wenn er sich richtig entscheidet, ist auf der natürlichen Seite kleiner als auf der unnatürlichen (Annahme 4). Für den Torwart gelten dieselben Annahmen jeweils umgekehrt. Auch hier wird davon ausgegangen, dass diese Annahmen »common knowledge« für beide Spieler sind (vgl. oben). Aus diesen Annahmen lassen sich eine Reihe von testbaren Hypothesen ableiten (für die Herleitung siehe Chiappori et al. 2002).12 12) Die hier dargestellten Hypothesen beziehen sich allesamt auf das Aggregat der Schützen und der Torhüter. Aus soziologischer Sicht stellen diese den zentralen Prüfstein für die hier verfolgte Anwendung der Spieltheorie dar. D.h., dass die Spieltheorie hier als eine Theorie betrachtet wird, die mittels verallgemeinernden Annahmen über individuelles Verhalten empirisch prüfbare Aussagen zu Zuständen auf der sozialen Aggregatebene macht (vgl. z.B. Coleman 1986; 1990). Allerdings können mittels der vorgeführten spieltheoretischen Analyse auch Hypothesen formuliert werden, die sich auf individuelle Spieler beziehen, die mehrere Elfmeter geschossen haben bzw. dabei im Tor standen. Auf die Darstellung dieser Hypothesen wird hier verzichtet, da sie für die soziologische Untersuchung des Gegenstands nicht entscheidend sind. Eine entsprechende Analyse findet sich in Berger / Hammer (2007). 404 Roger Berger und Rupert Hanlmer H1: Die Randomisiemngen durch den Schützen und den Torwart sind unabhängig voneinander. H2: Der Schütze hat eine höhere Wahrscheinlichkeit, in die Mitte zu schießen, als der Torwart, dort stehen zu bleiben. H3a: Die Wahrscheinlichkeit des Torerfolgs ist gleich groß, egal ob der Schütze nach »Links«, »Rechts« oder in die »Mitte« schießt. H3b: Die Wahrscheinlichkeit ein Tor zu verhindern ist gleich groß, egal ob der Torwart nach »Links« oder »Rechts« springt oder in der »Mitte« stehen bleibt. H4a: Der Schütze hat eine größere Wahrscheinlichkeit, seine natürliche Seite (»Rechts«) zu wählen. H4b: Der Torwart hat eine größere Wahrscheinlichkeit, die natürliche Seite des Schützen (»Rechts«) zu wählen. H5: Der Torwart hat eine größere Wahrscheinlichkeit, die natürliche Seite des Schützen (»Rechts«) zu wählen, als dass der Schütze dorthin schießt. H6: Die Kombination (»Rechts«, »Rechts«) ist wahrscheinlicher als die beiden Kombination (»Links«, »Rechts«) und (»Rechts«, »Links") und diese wiederum sind wahrscheinlicher als die Kombination (»Links«, »Links«). Es ist zu erkennen, dass jeder der heiden Spieler seine Entscheidung jeweils an den Auszahlungen des Gegners orientiert. Es wird so gewählt, dass beide Spieler indifferent zwischen ihren reinen Strategien sind und sich nur noch an den Wahrscheinlichkeitsverteilungen für die Aktionen des Gegners orientieren, wodurch sich ein gemischtes Gleichgewicht ergibt. So liegt der Grund dafür, dass der Torwart seltener die Mitte wählt, als der Schütze dorthin schießt, in den Kosten eines Schusses in die Mitte für den Schützen. Wählt der Torwart dann nämlich auch die Mitte, so ist die Trefferwahrscheinlichkeit sehr gering (vgl. Abb. 2). Für den Torwart sind die erwarteten Kosten eines Schusses in die Mitte dagegen immerhin geringer als diejenigen eines Schusses in die gegenüberliegende Ecke (vgl. Annahme 2). Da sich der Schütze an diesen Kosten für den Torwart orientiert, ist die Gleichgewichtswahrscheinlichkeit für Schüsse in die Mitte für den Schützen höher, denn erwartet »teure« Aktionen werden selten gewählt, erwartet »billige« dagegen häufig. Wäre dies nicht der Fall, so wären die Spieler füreinander berechenbar und sie könnten sich jeweils verbessern, wenn sie ihre Entscheidung in Richtung der Hypothese verschieben würden. Dies kann veranschaulicht werden, wenn man sich die Elfmetersituation für einen einarmigen Torwart vorstellt. Würde dieser gehandicapte Spieler gleich häufig nach links und rechts springen, würde der Schütze ausschließlich auf die Seite mit dem fehlenden Arm schießen, weil die Trefferwahrscheinlichkeit dort offensichtlich höher ist. Deshalb würde sich der Torwart an dieser Auszahlung orientieren und entsprechend häufiger auf die Seite mit dem fehlenden Ann springen, bis die Erfolgswahrscheinlichkeit für den Schützen auf beide Seiten gleich hoch wäre. Für die empirische Überprüfung der Hypothesen muss beachtet werden, dass sich dabei jeweils ein statistisches Aggregationsproblem ergibt. Erstens können Häufigkeiten und Wahrscheinlichkeiten nicht bei einzelnen Elfmetersituationen beobachtet werden, sondern nur im Aggregat aller Spieler und Situationen. Zweitens bildet die empirisch gemessene Häufigkeit nur dann die theoretisch erwartete Wahrscheinlichkeit ab, wenn alle Spieler und Elfmetersituationen homogen sind, wenn also alle Spieler immer da~selbe Spiel spielen. Sollte dagegen in der Population aller Elfmetersituationen Heterogenität existieren, wäre die Wahrscheinlichkeitsmessung verzerrt. Nun können zumindest einige mögliche Heterogenitätsvermutungen ausgeschlossen werden. Es besteht Gleichheit der Elfmetersituation unab- Die doppelte Kontingenz von Elfmeterschüssen hängig vom Spielstand, Spielzeit, vom Torwart und vom Schussfuß des Spielers. Heterogenität (die theoretisch schon einbezogen wurde) besteht allerdings bei der Schussrichtung des Spielers in Abhängigkeit vom Schussfuß. Die Zahl der potentiellen Heterogenitätsquellen ist jedoch größer und potentiell unbekannt. Zwar erlaubt gerade die hoch standardisierte Elfmetersituation im Verbund mit einigen Fußballkenntnissen die plausible Annahme, dass für die zentralen Quellen von Heterogenität bereits kontrolliert wird. Mit Sicherheit festgestellt werden kann dies jedoch nicht. Dies liegt schon daran, dass zu einer statistischen Kontrolle nur die verfügbaren Variablen herangezogen werden können. Begegnet werden kann der Problematik allerdings, indem die Hypothesen als Häufigkeits- statt als Wahrscheinlichkeitsaussagen formuliert werden. Damit wird zwar ihr Informationsgehalt verringert, jedoch sind sie robuster und sollten auch dann noch zutreffen, wenn in den Daten selektive Verzerrungen auftauchen (vgl. Chiappori et al. 2002, S. 1143f). 3.2 Parsans und die doppelte Kontingenz beim Elfmeterschuss Von der Spieltheorie beeinflusst war Parsons, als er das Konzept der doppelten Kontingenz in die Soziologie einführte (vgl. Ganssmann 2006, S. 152). Dies ist erkennbar an seiner entsprechenden Definition, deren Grundelemente mit derjenigen der Spieltheorie vereinbar sind, nämlich, dass die Akteure »ego« und »alter« (Parsons et al. 2001, S. 16) »among available alternatives« (ebd.) eine auswählen, nachdem sie komplementäre »expectations« (ebd.) gebildet haben. Die Auszahlungen (»gratifications« (ebd.» von Ego hängen dabei auch von der Auswahl von Alter ab und umgekehrt. Die Auflösung der doppelten Kontingenz hat dann die folgenden Eigenschaften. »[ ... ] since the outcome of ego's action (e.g. success in the attainment of a goal) is contingent on alters reaction to what ego does, ego becomes oriented not only to alter's probable overt behavior but also to what ego interprets to be alter's expectations relative to ego's behavior, since ego expects that alter's expectations will influence alter's behavior.« (Parsons I Shils 1951, S. 105, Hervorhebungen im Original). Weiter wird festgestellt, dass diese Erwartungen reziprok oder komplementär sein müssen. Es ist schwierig, darin nicht die Umschreibung eines Gleichgewichts in Erwartungen und Handlungen zu sehen, dessen prinzipielle Existenz Nash (1950) für alle real zu erwartenden Situationen strategischer Interaktionen bewiesen hat (vgl. oben). Allerdings gibt Parsons die spieltheoretische Annahme auf, dass die Akteure jeweils Spielausgänge mit hohem Nutzen solchen mit niedrigem Nutzen vorziehen. Stattdessen geht er davon aus, dass die doppelte Kontingenz erst durch geteilte und stabile kulturelle Muster (Bedeutungen, Werte und Normen) aufgelöst werden kann. Damit kann er auch auf die Annahme des »common knowledge« verzichten. Ego braucht keine Erwartungen über Alter zu bilden. Er orientiert sich einfach an dem geteilten kulturellen Muster. Falls dieses wirklich von beiden Akteuren geteilt wird (und nur dann kann die doppelte Kontingenz aufgelöst werden), wird sich auch Alter daran orientieren, so dass die wechselseitigen Erwartungen erfüllt werden. Das eigentliche Problem eines Akteurs im Sinne von Parsons besteht dann darin, eine Erwartung darüber zu bilden, ob der andere Akteur das kulturelle Muster tatsächlich stabil mit ihm teilt. In den Medienberichten zum Elfmeterschießen mit dem deutschen Torwart Lehmann bei der WM 2006 wurde häufig davon ausgegangen, dass dies tatsächlich möglich ist. Lehmann wurde nämlich vom Trainerstab auf einem Zettel mitgeteilt, dass z.B. der Schütze Ayala rechts schießen werde. Tatsächlich tat er dies auch und Lehmann konnte den Ball dort abwehren. 13 Eine tiefere Betrachtung zeigt jedoch, dass ein solches Muster weder geteilt noch stabil sein kann. Denn wenn Ayala tatsächlich wüsste, dass Lehmann seine Schussrichtung »rechts« kennen würde, und Lehmann wüsste dies auch, usw. usf. (was das 13) Lehmann wehrte noch einen weiteren Strafstoß ab und Deutschland gewann das Viertelfinale gegen Argentinien mit 4:2. Dies bescherte dem Torwart und seinem ominösen Zettel einige Medienpräsenz. 406 Roger Berger und Rupert Hammer Muster zu einem geteilten machen würde), würde Ayala nicht dorthin schießen. Oder er würde gerade diese Richtung wählen, weil Lehmann in Antizipation dessen die Seite gewechselt hat, etc. Die doppelte Kontingenz kehrt damit auf einer zweiten Ebene zurück und destabilisiert jedes evtl. vorhandene Verhaltensmuster. 14 Obschon diese Frage offensichtlich Analogien mit der hier geteilten aufweist, soll sie hier nicht weiter analysiert werden. Denn das Beispiel des Elfmeterschusses zeigt schon, dass der Ansatz durch diesen Wechsel der Handlungstheorie an Reichweite verliert. Das Problem des Parsons'schen Ansatzes wird auch deutlich, wenn man sich vergegenwärtigt, welche Art von doppelter Kontingenz dadurch in idealer Weise gelöst werden kann. Dies sind Koordinationsprobleme, bei denen die Interessen der Beteiligten vollständig deckungsgleich sind. 15 Diese weisen - in spieltheoretischen Termini ausgedrückt - mehrere gleichwertige Gleichgewichte auf. Die Auswahl eines Gleichgewichtspunktes ist dann tatsächlich durch kulturelle l\1uster oder »conventions« (Parsons et al. 2001, S. 16) gewährleistet (wie das Beispiel des Links- oder Rechtsverkehrs anschaulich zeigt). Sollte in einer bestimmten Situation jedoch keine Konvention bestehen, so bedingt Parsons Modell Aushandlungsprozesse, in denen es zu einer »reaction« (ebd., Hervorhebung RB I RH) von Alter auf Egos Aktion kommt. D.h. dieser Aushandlungsprozess läuft zeitlich gestaffelt im Schema »Aktion, Reaktion, Reaktion auf die Reaktion, etc.« ab. Damit ergeben sich drei Gründe, wieso Parsons Ansatz in der Elfmetersituation nicht anwendbar ist. Erstens handelt es sich hierbei ohne Zweifel um eine Situation, in der die Akteure vollständig eigennutzorientiert sind. Es wäre unsinnig diese Annahme aufzuheben. Selbst wenn die Akteure diese Präferenzen nicht hätten, würde sie ihnen durch die Spielstruktur aufgezwungen. Denn es handelt sich beim Elfmeterschuss um ein Nullsummenspiel, in dem der Gewinn von Ego genau der Verlust von Alter ist und umgekehrt. Solange ein Spieler also nicht vollständig altruistisch ist, muss er egoistisch sein. Der Ansatz von Parsons ist damit (mindestens) auf Nicht-Nullsummen-Interaktionen beschränkt, in denen sich Kooperationsgewinne erzielen lassen. 16 Zweitens ist die Suche nach geteilten kulturellen Mustern o.Ä. hier sinnlos, weil beide Spieler sich gerade nicht verstehen und auf ein entsprechendes Muster zurückgreifen wollen. Jede solche geteilte Regelmäßigkeit (falls sie tatsächlich existieren sollte) wird von beiden Spielern sofort unterlaufen werden, um den Gegner zu täuschen und Instabilität in der Interaktion zu erzeugen und damit die von Parsons als notwendig erachtete Bedingung für die Auflösung der doppelten Kontingenz zu untergraben (Parsons et al. 2001, S. 16). Nur ein einziges Muster kann von den beiden Spielern nicht zerstört werden, ohne sich selbst zu schaden und dies ist dasjenige, das sich durch die gemischten Strategien im Gleichgewicht ergibt. Man könnte nun einwenden, dass das gemeinsame kulturelle Muster hier z.B. die Ak14) Der »Zettel« selbst belegt diese These übrigens auch empirisch. Von den vier argentinischen SchUtzen (der letzte trat nicht an, da die Entscheidung schon gefallen war) waren nur zwei darauf aufgeführt. Beide schossen auch wirklich in die vorhergesagte Richtung. Einen Schuss davon konnte Lehmann parieren. Eine Bilanz, die auch ohne Zettel durchaus im Bereich des Wahrscheinlichen liegt. Lehmann bestätigte dies auch indirekt, indem er später angab, er habe die Informationen sowieso nicht entziffern konnte, weil die Schrift verschmiert gewesen sei. 15) Das einfachste Beispiel für eine solche Koordinationssituation ist die doppelte Kontingenz, die zwei kreuzende Autofahrer zu lösen haben: nämlich, ob beide links oder rechts fahren. Dies stellt die Fahrer normalerweise vor keinerlei Probleme, da eines der beiden (reinen) Gleichgewichte [links, links] oder [rechts, rechts] eindeutig durch die jeweilige Straßenverkehrsordnung vorgegeben ist und keiner der Fahrer einen Anreiz hat, von dieser Norm abzuweichen. 16) Dazu gehören auch Interaktionssituationen, in denen sich die Interessen der Beteiligten nur partiell überlappen, wie etwa das bekannte Gefangenendilemma. Die doppelte Kontingenz von Elfmeterschüssen 4U7 zeptanz der Spielregeln sei. Dies ist aus zwei Gründen falsch. Zum einen ist das Explanandum hier die Elfmetersituation bzw. die empirische Verteilung der daraus folgenden Handlungen und nicht z.B. die Einwilligung in Spiel und Regeln o.Ä. Zum anderen besteht Fußball- und jedes andere (sportliche) Spiel- (auch) aus einer Menge von gleich oder ähnlich strukturierten Nullsummenspielen, die theoretisch analog gelöst werden können. 17 Das Regelwerk des Elfmeters macht diese Lösung nur für die empirische Analyse einfacher zugänglich als andere Spielsituationen, die keiner Spielregel unterworfen sind. Dies zeigt z.B. die Analyse des Schusses aufs Tor aus dem Halbfeld (vgl. unten, Moschini 2004). Damit ist gezeigt, dass die bei der Elfmetersituation resultierenden Regelmäßigkeiten nicht auf geteilten kulturellen Mustern beruhen. Da nun aber kein kulturell geteiltes Deutungsmuster der Elfmetersituation zwischen den beiden Spielern vorliegen kann, das über die spieltheoretisch erklärbaren Regelmäßigkeiten hinausgeht, müsste dieses drittens gemäß Parsons Ansatz in einem zeitlich gestaffelten Prozess ausgehandelt werden. Dies ist nun allerdings empirisch offensichtlich nicht Fall, da beim Elfmeterschuss simultane Aktionen vorliegen. Entsprechende Prozesse müssten dann vor dem Strafstoß stattfinden und sind schon deshalb unmöglich, weil die beiden Kontrahenten bis kurz vor der Interaktion nicht wissen können, dass sie aufeinandertreffen. Zusammenfassend kann deshalb festgehalten werden, dass dem Ansatz von Parsons zwar verschiedene Formen der doppelten Kontingenz theoretisch zugänglich sind. Die Menge der doppelten Kontingenzen, die nach Parsons lösbar sind, umschließt aber nur eine Teilmenge der spieltheoretisch fassbaren. Weil die Situation des Elfmeterschusses nicht dazu gehört, erübrigt sich eine entsprechende empirische Analyse. 3.3 Luhmann und die doppelte Kontingenz beim Elfmeterschuss Ein ähnliches Bild zeigt sich, wenn man die Ausführungen Luhmanns zur doppelten Kontingenz betrachtet. Luhmann lässt die Eigennutzannahme ebenfalls nicht zu. Im Gegensatz zu Parsons ersetzt er sie aber nicht durch eine anders geartete Handlungstheorie (bei Parsons: Orientierung an kulturellen Mustern), sondern lässt die damit verknüpften Fragen weitgehend offen. Damit kann mit Luhmann vorerst nichts empirisch Gehaltvolles zur Strafstoßsituation gesagt werden. Konsequenterweise stellt er deshalb auch fest, dass in Situationen doppelter Kontingenz apriori keine Handlungen stattfinden, bzw. dass alle Ansätze, die auf Handlung abstellen, hier nicht greifen können (vgl. z.B. Ganssmann 2006, S. 153; Vanderstraeten 2002, S. 85). Luhmann geht sogar noch einen Schritt weiter und behauptet, dass sogar schon »[d]er Versuch, [in einer Situation doppelter Kontingenz] den anderen zu berechnen, [ ] zwangsläufig scheitern [müsse]« (Luhmann 1988, S. 156). Es sind also nicht nur keine Handlungen denkbar, sondern auch die Bildung von Erwartungen ist unmöglich. 18 Geschweige denn können Vorhersagen über zu erwartende soziale Muster oder Regelmäßigkeiten getroffen werden. Diese Ansicht ist nun spätestens seit Nash (1950) eindeutig widerlegt, und oben wird eine entsprechende konkrete Umsetzung vorgeführt. Zudem ist offenbar auch noch kein Elfmeterschuss daran gescheitert, dass sich der Schütze nicht für eine Schussrichtung entscheiden konnte. Deshalb wird nun die einschlägige Lösung von Luhmann betrachtet. Er schlägt vor auf das Konzept von Kommunikation zurückzugreifen. Diese kann hier etwa aus der Körpersprache 17) Der probabilistische Charakter der entsprechenden Lösungen macht ja den Reiz dieser Spiele aus. Denn ob schon im Durchschnitt klar ist, wie eine entsprechende Situation ausgeht (z.B. landen etwa 75% aller Elfmeterschüsse im Tor), muss dies im Einzelfall durchaus zutreffen. 18) Vgl. ähnlich auch Vanderstraeten (2002, S. 85): «The participants are opaque and incalculable to one another«. 408 Roger Berger und Rupert Hammer des Schützen bei der Vorbereitung des Strafstoßes, beim Anlauf oder aus Finten des Torwarts u.Ä. bestehen. 19 Allerdings wird diese Kommunikation - genauso wie die geteilten Deutungsmuster in Parsons Ansatz - ausschließlich darauf ausgerichtet sein, den Gegner zu täuschen. Das Antäuschen einer Schussrichtung beim Anlauf kann dann bedeuten, dass der Schütze dorthin schießt, oder eben gerade nicht. Die doppelte Kontingenz setzt sich also auf der Ebene von Kommunikation fort und wird dadurch nicht gelöst. Auch eine Auflösung des Zirkels der wechselseitigen Erwartungen durch eine Sequenzialisierung der Erwartungen und den daraus folgenden Aktionen ist nicht möglich. Wie oben dargestellt wird der Torwart sich nie für eine Aktion entscheiden, bevor der Schütze dies nicht tut, und umgekehrt. Denn eine entsprechende Aktion würde dem Gegner tatsächlich eindeutig und glaubwürdig kommunizieren, wie die doppelte Kontingenz zu seinen Gunsten gelöst werden kann. Es kann auch angeführt werden, dass das Zustandekommen einer Elfmetersituation an sich schon die Folge von Kommunikation und anschließender Systembildung ist. Der Strafstoß ist dann schon eine strukturierte doppelte Kontingenz und weist nicht mehr die prinzipielle Offenheit einer reinen doppelten Kontingenz auf. Auch dieser Einwand führt allerdings nicht weiter. Denn erstens ist, wie oben schon aufgeführt, auch hier das Explanandum das Verhaltensmuster beim Strafstoß und nicht z.B. dessen konstituierende Regeln. Unterstellt man zweitens dennoch, dass die doppelte Kontingenz der Elfmetersituation durch vorgängige Systembildung bereits strukturiert ist, so müsste deren Auflösung dadurch gegenüber einer völlig offenen Situation sogar erleichtert sein. Dies ist jedoch nicht der Fall. Vielmehr kreiert die Elfmeterregel ja erst die doppelte Kontingenz. Und offenbar müssen die Spieler beim Elfmeter genauso den Zirkel von wechselseitigen Erwartungen lösen wie die Akteure in unstrukturierten Situationen, wie sie z.B. unten in der Diskussion beschrieben werden. Definitorische Umdeutungen geben der Analyse hier also keinen empirischen Gehalt. Luhmann gibt jedoch einen Hinweis, wie dies geschehen kann. Falls nämlich ein (oder wie im hier untersuchten Fall: mehrere) Beobachter feststellt, dass er bei einem Strafstoß auf zwei psychische Systeme zuschreibbare Handlungen beobachtet (vgl. Vanderstraeten 2002, S. 85), ergibt sich daraus, dass das System in »Gang gesetzt« wird und sich die Partner an der Frage orientieren, »ob eine Handlung ihm nützen oder schaden wird« (Luhmann 1988, S. 160, Hervorhebung im Original). Damit landet man auch mit Luhmann letztlich bei der Spieltheorie. Man kann sich deshalb fragen, ob Luhmanns Ansatz allgemeiner ist und die spieltheoretische Analyse als eine Art Spezialfall enthält. 20 Diese Frage ist zu verneinen, wie eine weitere Betrachtung zeigt. Erstens hat Luhmann für die in der Spieltheorie übliche Annahme der Eigennutzorientierung wenig übrig und weist sie als viel zu »anspruchsvoll« ab, »als dass man sie allgemein voraussetzen könnte« (Luhmann 1988, S. 160). Abgesehen davon, dass diese Vermutung empirisch belegt und nicht apriori behauptet werden sollte, erweist sich die Annahme eigennützigen Verhaltens gerade in der Elfmetersituation als die einzig vernünftige Prämisse. Dennoch könnte man davon ausgehen, dass Luhmann die hier untersuchte Form der doppelten Kontingenz zwar etwas stiefmütterlich behandelt, die spieltheoretische Lösung aber durchaus gelten lässt. Dies ist jedoch falsch, denn Luhmann lehnt die Idee, dass es in einem System von wechselseitig aufeinander bezogenen Erwartungen und daraus resultierenden Handlungen ein Gleichgewicht geben kann - also die Konzeption des 19) Allerdings werden solchen Aktionen durch die Regeln Grenzen gesetzt. Z.B. darf der Torhüter die Torlinie während der Ausführung des Elfmeters nicht verlassen und der Schütze darf den Anlauf nicht unterbrechen. 20) Immerhin hat Luhmann die Entwicklung der Spieltheorie durchaus zur Kenntnis genommen (vgl. Luhmann 1973). Die doppelte Kontingenz von Elfmeterschüssen 409 Nash-Gleichgewichts - explizit ab, wenn er behauptet: »Dies [die Antizipation von Alter durch Ego und umgekehrt, RB / RH] kann nicht in Form von verleinerter Voraussicht geschehen, weil dies das Problem nur neu ins Spiel bringen würde« (Luhmann 1988, S. 171; ähnlich z.B. Vanderstraeten 2002, S. 86). Damit geht Luhmann einen Schritt weiter als Parsons. Bei diesem ist noch denkbar, spieltheoretische Überlegungen in das Theoriegebäude einzubeziehen. Diesem Weg verschließt sich Luhmann prinzipiell. Und dies nicht nur für das betrachtete Spiel, sondern - wenn die obige Aussage ernst genommen wird - für sämtliche spieltheoretische Analysen. Damit, und weil die Kommunikationslösung hier nicht denkbar ist, ergeben sich auch aus dem Ansatz von Luhmann keine empirisch gehaltvollen Aussagen zur Lösung der doppelten Kontingenz des Elfmeterschusses. Daher beschränkt sich die nachfolgende empirische Analyse auf die Analyse spieltheoretisch begründeter Hypothesen. Zuvor wird der einschlägige Forschungsstand zusammengefasst. 4. Bisherige Evidenz zu gemischten Gleichgewichten Die empirische Forschung zum Verhalten von Menschen in Nullsummenspielsituationen ist überschaubar. Große Teile der einschlägigen Untersuchungen fanden dabei im Labor statt, und nur wenige unter realen Bedingungen. 4.1 Tests aufgemischte Gleichgewichtsentscheidungen in Laboruntersuchungen Es zeigt sich, dass in verschiedenen strategischen Entscheidungssituationen mit gemischten Gleichgewichten diese tendenziell erreicht werden. Dies gilt sowohl für Situationen mit der hier betrachteten »matching pennies«-Struktur (vgl. Mookehrjee / Sopher 1994), als auch fUr andere Nullsummenspiele (vgl. Brown / Rosenthal1990; O'NeillI987; 1991; Rapoport / Boebe11992; Rosenthai et al. 2003; Shachat 2000; 2002) und allgemeine Spiele mit gemischten Gleich~ewichten (vgl. Bloomfield 1994; Erev / Roth 1998; McKelvey et al. 2000; Ochs 1995). 1 Allerdings zeigen sich häufig Lerneffekte derart, dass in wiederholten Spielen die vorhergesagten Gleichgewichte eher erreicht werden als mit unerlahrenen Akteuren bzw. in einfach gespielten Spielen. 4.2 Tests aufgemischte Gleichgewichte anhand von realen Interaktionen im Sport Bisher existieren nur wenige Untersuchungen zu gemischten Gleichgewichten in realen Interaktionen. Diese beziehen sich alle auf Interaktionen im Sport, wahrscheinlich aus den beschriebenen methodischen Gründen. Fußball Zwei Analysen befassen sich mit der hier untersuchten Elfmetersituation. Chiappori et al. (2002) untersuchen alle 459 Strafstöße der ersten französischen (Spielzeiten 1997-1999) und italienischen (Spielzeiten 1997-2000) Liga. Die Autoren können alle Hypothesen bestätigen. Sie verwenden dabei die Modellierung mit den drei Strategien {Links, Mitte, Rechts}. Palacios-Huerta (2003) verwendet einen umfangreicheren Datensatz, der 1417 Strafstöße aus den Profiligen Spaniens, Englands und Italiens von 1995 bis 2002 umfasst. Wiederum können alle Hypothesen vollständig bestätigt werden. Allerdings modelliert der Autor nur 21) Neben dem hier im Fokus stehenden Nullsummenspiel »matching pennies« existieren auch verschiedene andere Spiele. die ebenfalls nur ein Gleichgewicht in gemischten Strategien aufweisen, aber keine Nullsummenspiele sind und / oder mehr als zwei Entscheidungsmöglichkeiten haben (vgl. z.B. Rasmusen 1998, S. 67ff). 410 Roger Berger und Rupert Hammer den Strategienraum {Links, Rechts}. Dafür untersucht er die Elfmeterentscheidung auch noch bei Elfmeterschießen in Turnieren, in denen der Torwart mindest fünf aufeinander folgende Entscheidungen treffen muss. Er kommt dabei zu der Folgerung, dass sich die Torhüter auch in dieser Situation rational verhalten. Moschini (2004) analysiert eine andere Spielsituation im Fußball, nämlich den Schuss aufs Tor aus dem rechten bzw. linken Halbfeld. Hierbei müssen sich die Schützen entscheiden, ob sie in die nähere Torecke (nach rechts von rechts und umgekehrt) oder in die entferntere (nach links von rechts und umgekehrt) schießen. Die Torhüter müssen sich entscheiden, ob sie eben diese nahe oder die entfernte Ecke besonders abdecken wollen. Die Situation ist insofern interessant, als die beiden Entscheidungen offenbar nicht die gleichen Erfolgschancen versprechen. Ein Schuss in die nahe Ecke ist einfacher zu bewerkstelligen als einer in die entferntere Ecke. Für den Torwart ist umgekehrt ein Schuss in die entfernte Ecke einfacher abzuwehren. Weil sich die Spieler aber wechselseitig an ihren erwarteten Auszahlungen orientieren, werden mehr Schüsse auf und mehr Tore in der entfernten Ecke erwartet, welche für den Schützen schwieriger zu treffen und für den Torwart einfacher abzusichern ist. Moschini kann diese Hypothesen anhand von Daten aus der italienischen ersten Liga der Spielzeit 2002-2003 bestätigen. Die doppelte Kontingenz von E/fmeterschüssen ben. Jede Situation ist dabei durch die folgenden, in Tabelle 1 zusammengefassten Angaben beschrieben: Beteiligte Schützen und Torhüter, Schussfuß des Schützen, Richtung des Torschusses (Links, Mitte, Rechts), Sprungrichtung der Torhüter (Links, Mitte, Rechts) und das resultierende Ergebnis in vier Kategorien (»Tor«, »vorbeigeschossen«, »PfostenlLatte« und »vom Torhüter abgewehrt«.). Die Richtungen werden einmal originär vom jeweiligen Spieler aus gesehen eingetragen und einmal in der beschriebenen einheitlichen Notation als »natürliche« Richtung. Tabelle 1: Deskription des Datensatzes Schussfuß Schützen 5. Datensatz und Ergebnisse Nach einer Beschreibung des verwendeten Datensatzes werden die Ergebnisse der damit durchgeführten Hypothesentests dargestellt. Dabei werden vorerst die zu Grunde gelegten Annahmen überprüft. 5.1 Daten Der verwendete Datensatz22 enthält Angaben zu allen 1043 Elfmetersituationen, die in den Spielzeiten 1992 / 1993 bis 2003 / 2004 der ersten deutschen Bundesliga stattgefunden ha22) Die Daten wurden von der Firma IMP AG erhoben. Diese beobachtet Bundesligaspiele, um die Daten anschließend an Interessenten, z.B. an die beteiligten Mannschaften, zu verkaufen. Dabei werden nicht nur Elfmetersituationen, sondern sämtliche Aktionen eines Spiels von insgesamt vier professionellen Beobachtern dokumentiert. Ergebnis R L Mitte R Tor vorbei prostenl Latte 377 666 441/433 151 451/459 788 27 24 520/542 17 506/484 Torhüter Die bisherige Evidenz zeigt damit, dass die spieltheoretischen Vorhersagen zu gemischten Gleichgewichten als Lösung von doppelten Kontingenzen bestätigt werden können; in realen Situationen vollständig, im Labor mit einigen Abstrichen. Im Folgenden wird untersucht, ob die obigen Hypothesen auch auf die Entscheidungen von Bundesligaspielern zutreffen. Schuss bzw. Sprungrichtung jeweils originärl »natürlich« L Tennis Die untersuchte Interaktionsstruktur findet sich jedoch nicht nur beim Fußball, sondern z.B. auch beim Tennis. Walker / Wooders (2001) analysieren dazu die Aufschlag- und Returnentscheidungen von professionellen Tennisspielern. Diese können jeweils auf die linke oder rechte Seite des Feldes aufschlagen. Der Return-Spieler wählt ebenso eine Seite aus. Die zentralen Hypothesen ergeben sich auch hier aus denselben theoretischen Überlegungen: Damit die beiden Spieler füreinander unberechenbar bleiben, muss die Wahrscheinlichkeit eines Punktgewinns unabhängig von der Seitenwahl sein (für beide Spieler, da es sich auch hier offensichtlich um ein Nullsummenspiel handelt). Anhand von vierzig Finalspielen bei Grand Slam- und Masters-Turnieren werden diese Hypothesen überprüft. Die Gleichheit der Gewinnwahrscheinlichkeiten (unabhängig von der gewählten Seite) kann eindeutig bestätigt werden. 411 23 abgewehrt 204 Die erste Zahl bei der Schuss- bzw. Sprungrichtung L (»Links«) und R (»Rechts«) bezeichnet die tatsächliche Richtung des Schusses bzw. des Sprungs, jeweils vom ausführenden Spieler aus gesehen. Die zweite Zahl bezieht sich auf die natürliche »rechte« und unnatürliche »linke« Richtung vom Torwart aus gesehen; dabei werden Schüsse und Sprünge auf die - vom Torwart aus gesehen - rechte Seite bei Rechtsfüßem als natürlich und bei Linksfüßern als unnatürlich gezählt. 5.2 Test der Annahmen Um das dargestellte Modell der Elfmetersituation mit dem Datensatz empirisch überprüfen zu können, müssen drei Annahmen erfüllt sein: Die Schützen müssen das gleiche Spiel spielen, unabhängig davon, welchen Schussfuß sie benutzen,24 und die Schützen und Torhüter müssen das gleiche Spiel spielen, unabhängig davon, welche Entscheidung sie treffen. Um die empirischen Häufigkeiten als Wahrscheinlichkeiten interpretieren zu können, ist weiterhin wichtig, dass das Spiel auch durch den Erwartungsdruck auf den Schützen nicht verändert wird. Der Erwartungsdruck wird durch den Spielstand, das Heimrecht (jeweils aus der Sicht des Schützen) und die Halbzeit, in der die Strafstoßsituation stattfindet, approximiert. Ergibt sich hier keine Heterogenität in den Daten, ist dies ein starker Hinweis auf eine homogene Spielsituation bei allen Strafstößen. Dies ist auch tatsächlich der Fall. In der logistischen Regression mit den obigen unabhängigen Variablen jeweils auf die Wahrscheinlichkeit, ein Tor zu erzielen, ein Tor abzuwehren, und die Wahrscheinlichkeit »Links« oder »Rechts« zu wählen findet sich kein signifikanter 25 Einfluss. Der höchste t-Wert einer unabhängigen Variable beträgt t=1,11 und zeigt, dass 23) Es handelt sich nur um Meisterschaftsspiele. Der Datensatz enthält also keine Beobachtungen zu Elfmeterschießen, wie sie bei unentschiedenem Spiel am Ende von Pokalspielen ausgetragen werden. 24) Die Frage, ob das Spiel sich in Abhängigkeit des Schussfußes unterscheidet, differiert von derjenigen, ob der Schuss auf die natürliche Seite einfacher ist. 25) Aus Einfachheitsgründen wurde der Schuss in die Mitte der natürlichen Seite zugeschlagen. Ein entsprechender Test mit einer multinomialen logistischen Regression, die alle drei Kategorien berücksichtigt, ändert den Befund aber nicht. 412 Roger Berger und Rupert Hammer das Spiel durch die unabhängigen Variablen nicht beeinflusst wird. Das maximale PseudoR 2 ist mit 0,0013 extrem gering und zeigt ebenfalls, dass die für die theoretische Analyse getroffenen Annahmen empirisch vollständig bestätigt werden können. 26 Die doppelte Kontingenz von Elfmeterschüssen 413 Tabelle 2b: Empirische Verteilung der Trefferwahrscheinlichkeiten des Schützen Torhüter Damit kann die eigentliche Überprüfung der Hypothesen vorgenommen werden. Inhaltlich zeigt sich hier außerdem schon, dass die Spieler sich insofern rational verhalten, als sie ihre Entscheidungen nicht durch einen erhöhten Erwartungsdruck verändern. Links Schütze Mitte Links 52,5% 83,3% 96,0% 75,5% Mitte 74,2% 33,3% 64,00/0 67,5% Rechts 91,8% 1000/0 64,5% 78,2% 73,1% 82,4% 77,50/0 75,60/0 5.3 Hypothesentests Die Hypothesen werden in der Reihenfolge der theoretischen Darstellung überprüft. H 1: Unabhängigkeit der Strategien von Schütze und Torwart Tabelle 2a zeigt die gemeinsame Verteilung der Strategiewahlen von Schützen und Torhütern. Der X2-Wert der Verteilung beträgt 2,5 bei 4 Freiheitsgraden und ist mit einem Signifikanzniveau von 0,65 weit davon entfernt, einen statistischen Zusammenhang anzuzeigen. Wie bei einem gemischten Gleichgewicht erforderlich, erfolgen die Entscheidungen der beiden Spieler damit tatsächlich unabhängig voneinander. Damit ist im Übrigen auch gezeigt, dass die oben fußballtechnisch belegte Annahme der Simultanität der Entscheidungen in der Tat zutrifft. Wenn sich die Torhüter nach den Handlungen der Schützen richten würden, müsste sich dies derart bemerkbar machen, dass die Hauptdiagonale in Tabelle 2a stärker besetzt wäre. Im umgekehrten Fall, wenn die Schützen auf die Handlung der Torhüter reagieren würden, müsste die Gegendiagonale (ohne die Mitte) stärker besetzt sein. Die entsprechenden Fallzahlen betragen 436 und 448 und unterscheiden sich nicht signifikant (t-Wert=0,30). Tabelle 2a: Empirische Verteilung der Strategiewahlen von Torwart und Schütze als absolute Häufigkeiten und als Prozentanteile Torhüter Schütze Links Mitte Rechts Links 202 19,4% 6 0,60/0 225 21,6% 433 41,5% Mitte 62 5,9% 0,30/0 86 8,2% 151 14,5% Rechts 220 21,1% 0,80/0 231 22,1% 459 44,0% 484 46,4% 17 1,6% 542 52,0% 1043 100% 3 8 Rechts Die Strategiewahl »Rechts« bezeichnet jeweils den Schuss bzw. den Sprung auf die natürliche Seite des Schützen. Die Zahlen in den Zellen bezeichnen jeweils die empirische Erfolgswahrscheinlichkeit (d.h. den Quotienten aus den Treffern und allen Schüssen) für den Schützen bei der betreffenden Strategiekombination. Die Abwehrwahrscheinlichkeit für den Torwart ergibt sich jeweils als Gegenwahrscheinlichkeit (vgl. Abb. 2). H2: Wahl der Option »Mitte« Es ist eindeutig erkennbar, dass die Schützen eine weit höhere Wahrscheinlichkeit haben, in die Mitte zu schießen (151 bzw. 14,5% aller Schüsse gehen dorthin), als der Torwart, dort stehen zu bleiben (17 bzw. 1,6% aller Entscheidungen). Diese beiden Werte unterscheiden sich hochsignifikant (t-Wert=17,01). H3a: Gleichheit der Trefferwahrscheinlichkeit für alle Strategien Aus Tabelle 2b wird ersichtlich, dass insbesondere die beiden Seitenwahlen für die Schützen ähnliche Erfolgswahrscheinlichkeiten aufweisen. Für die Wabl der»Mitte« trifft dies nur bedingt zu. Die eigentliche Trefferwahrscheinlichkeit entspricht allerdings der erwarteten Auszahlung für eine Seitenwahl. Diese korrespondiert dabei mit dem Produkt aus dem erwarteten Nutzen für eine bestimmte Strategiewahl und der Wahrscheinlichkeit, mit der die Strategie gewählt wird. Da - wie oben theoretisch begründet - die natürliche Seite des Schützen empirisch tatsächlich mit geringeren Kosten (weil einfacher zu schießen) versehen ist, sollte der Schuss auf diese Seite etwas häufiger vorkommen. Allerdings sind die genauen Kosten, anders als etwa bei »matching pennies«, apriori unbekannt und können nur empirisch aus den beobachteten Trefferwahrscheinlichkeiten geschätzt werden. Von diesen kann dann auf die optimale Mischung der Strategien geschlossen werden. 27 Tabelle 3 berichtet die vorhergesagte und beobachtete Mischung der Seitenwahl für die Schützen und Torhüter. Wegen der wenigen Fälle, in denen der Torwart in der Mitte stehen geblieben ist, wird der Strategienraum dabei auf {Links, Rechts} beschränkt und die Mitte dabei zur natürlichen Seite gezählt (vgl. oben). Die Strategiewahl »Rechts« bezeichnet jeweils den Schuss bzw. den Sprung auf die natürliche Seite des Schützen. 26) Eine ausführliche tabellarische Darstellung der Analyse findet sich in Berger I Hammer (2007). 27) Für eine formale Herleitung der Beziehung siehe Berger / Hammer (2007). 414 Roger Berger und Rupert Hammer Tabelle 3: Vorhergesagte und tatsächliche Wahrscheinlichkeiten der Strategiewahlenfür Schütze und Torhüter in Prozent Torhüter Schütze Links Rechts Links Rechts vorhergesagte Wahrscheinlichkeit 35,2 64,8 47,2 52,8 tatsächliche Wahrscheinlichkeit 41,6 58,4 47,2 52,8 Die Strategiewahl »Rechts« bezeichnet jeweils den Schuss bzw. den Sprung auf die natürliche Seite des Schützen. Es zeigt sich, dass die Schützen in der Tendenz zwar richtig liegen, aber dennoch erkennbare Unterschiede zwischen vorhergesagtem und beobachtetem Mischungsverhältnis der Strategien vorliegen. Die Schützen könnten das Mischungsverhältnis optimaler gestalten, wenn sie etwas häufiger auf ihre natürliche (rechte) Seite schießen würden. H3b: Gleichheit der Abwehrwahrscheinlichkeitfür alle Strategien Tabelle 2b weist auch für die Torhüter ähnliche Abwehrwahrscheinlichkeiten für die beiden Seitenwahlen aus. Wiederum gilt dies nur bedingt für die Wahl der »Mitte«. Allerdings muss beachtet werden, dass für die Torhüter hierzu kaum Fälle vorliegen, sodass diese Analyse wenig aussagekräftig ist. Die vorhergesagte und tatsächliche Strategienmischung der Torhüter wird gleich berechnet wie die optimale Mischung der Schussrichtungen für die Schützen und mit der beobachteten Häufigkeit verglichen. In Tabelle 3 zeigt sich, dass die Torhüter perfekt zwischen den beiden Seiten mischen, da die vorhergesagten und beobachteten Wahrscheinlichkeiten identisch sind. H4a: Wahl der natürlichen Ecke durch Schützen Tatsächlich wählen die Schützen die natürliche rechte Ecke 459mal (46,4% aller Fälle) und damit signifikant häufiger (K-S Anpassungstest auf Gleichverteilung z=15,5, asymptotisch signifikant 0,000) als die linke (433mal, 41,0% aller Fälle, vgl. Tab. 2a). Die Hypothese kann bestätigt werden. 28 H4b: Wahl der natürlichen Ecke durch den Torwart Dasselbe gilt für die Torhüter. Diese antizipieren offenbar, dass es für die Schützen günstiger ist auf ihre natürliche Seite zu schießen und springen entsprechend signifikant häufiger (542mal, 52,0 % der Fälle) dorthin als in die linke Ecke (484mal, 46,4% der Fälle, K-S Anpassungstest auf Gleichverteilung z=16,9, asymptotisch signifikant 0,000, vgl. Tab. 2a).29 28) Alternativ kann hier auch ein t-Test durchgeführt werden. Dieser zeigt an, dass sich die Verteilung nicht signifikant von einer 50:50-Verteilung unterscheidet (t-Wert=O,87). Werden die Schüsse in die Mitte in Anlehnung an Palacios-Huerta (2003) dagegen zur natürlichen Seite gezählt, wird die Differenz größer und damit auch signifikant (t-Wert=5,56). 29) Der durch das in der vorangehenden Fußnote beschriebene analoge Vorgehen geschätzte t-Werte lautet hier t= 1,81 und zeigt nur eine knapp signifikante Differenz an. Die doppelte Kontingenz von Elfmeterschüssen 4f5 H5: Wahl der natürlichen Ecke durch Torwart und Schütze Es kann bestätigt werden, dass die Torhüter mit größerer Wahrscheinlichkeit auf die natürliche Seite springen als die Schützen dorthin schießen. 459 Schüsse (46,4 %) gehen in die natürliche Ecke, aber die Torhüter springen 542mal (52,0 %) dorthin (vgl. Tab. 2a). Diese Differenz ist jedoch nicht signifikant, wie ein entsprechender t-Test zeigt (t-Wert=0,24). Wird die Wahl der »Mitte« durch den Schützen zu dessen natürlicher Seite gezählt (vgl. oben), so ergibt sich ein signifikanter Unterschied mit einem t-Wert von 2,54. Wird weiterhin davon ausgegangen, dass in den Daten nicht identifizierbare, selektive Verzerrungen vorliegen, und die Hypothese deswegen als Häufigkeitsaussage formuliert, so ist die vorliegende Häufigkeitsdifferenz ebenfalls signifikant (t-Wert=2,63). H6: Abfolge der Strategiekombinationen Wie vorhergesagt ist die Kombination [R, R] mit 22,1% (231 Fälle) am häufigsten. Danach folgen mit [L, R] (21,6 %, 225 Fälle) und [R, L] (21,1 %, 220 Fälle) die beiden gemischten Fälle. Im Durchschnitt treten diese 223mal, und damit in 21,4 % der Fälle auf. Die seltenste der vier Kombination ist [L, L] mit 19,4 % (202) aller Strategiekombinationen. Ein Maximum Likelihood-Test zeigt allerdings, dass diese Unterscheide nicht signifikant sind. Die größte Differenz liegt zwischen den Kombinationen [R, R] und [L, L] vor und weist ein Signifikanzniveau von 16% auf. Für die anderen Kombinationen ist dieser Wert entsprechend geringer. Wird wiederum die Wahl der »Mitte« durch den Schützen zu dessen natürlicher Seite gezählt (vgl. oben), so ergeben sich hochsignifikante Unterschiede zwischen allen Kombinationen, mit Ausnahme der Differenzen zwischen den beiden Gruppen [L, L] [L, R] und [R, R] [R, L]. Insgesamt können die spieltheoretischen Vorhersagen damit weitgehend bestätigt werden. Dies gilt insbesondere für die Torhüter, die sich optimal verhalten. Die Schützen dagegen zeigen z.T. suboptimale Entscheidungen. Allerdings sind nicht alle untersuchten statistischen Beziehungen signifikant, obgleich sie immer in die erwartete Richtung weisen. Diese Einschränkung kann jedoch fallengelassen werden, wenn die Hypothesen nicht als Wahrscheinlichkeits-, sondern als Häufigkeitsaussagen formuliert werden und / oder in Anlehnung an Palacios-Huerta (2003) der Strategienraum auf {Links, Rechts} beschränkt wird. In diesem etwas weniger harten Test der Theorie können nur die Hypothesen 3a und 6 nicht vollständig bestätigt werden. 6. Diskussion Die Analyse der Elfmetersituation als idealtypisches Beispiel einer doppelten Kontingenz zeigt, dass nur die Spieltheorie diese, insbesondere von systemtheoretisch orientierten Soziologen als problematisch betrachtete, Situation theoretisch auflösen kann. Nur die Spieltheorie impliziert entsprechende empirisch testbare Hypothesen über das Explanandum der zu erwartenden Handlungsmuster, nicht aber die Ansätze von Parsons und Luhmann. Die spieltheoretischen Vorhersagen können zudem anhand eines Datensatzes zu Elfmeterschüssen in der ersten Fußballbundesliga weitgehend bestätigt werden. Der spieltheoretische Ansatz weist damit den zweifachen Vorteil einer größeren theoretischen Reichweite und der bestätigten empirischen Korrektheit gegenüber den beiden anderen betrachteten Ansätzen auf. Derjenige von Parsons ist zwar theoretisch auf Situationen anwendbar, die einen Kooperationsgewinn versprechen, nicht jedoch auf die hier untersuchten Nullsummenspiele, für die es keine sinnvollen Normen sozialen HandeIns geben kann 416 Roger Berger und Rupert Hamlner (es sei denn, diejenigen, die in vollständig rationalen Erwartungen gründen). Luhmann schließt zusätzlich explizit aus, dass die Spieler den auftretenden infiniten Regress von Erwartungen und daran anschließenden Handlungen auflösen können. Denn weil er jede Handlungstheorie und dadurch auch die »common knowledge«-Annahme aufgibt, zieht er genau den Nagel, der diesen Zirkel von Erwartungen festhält. Damit lassen sich aus den Ausführungen von Luhmann und Parsons apriori keine Lösungen für die doppelte Kontingenz bei vollständiger Konkurrenz ableiten. Dies gilt insbesondere dann, wenn es sich wie beim Strafstoß um ein Spiel mit simultanen Zügen handelt, das zusätzlich die Kommunikationslösung ausschließt. Hinzu kommt, dass in reinen Konfliktspielen die Eigennutzannahme keine empirisch zu bestätigende Vermutung über eine Eigenschaft der beteiligten Akteure ist. Vielmehr ergibt sie sich hier aus der Struktur der Interaktion und ist damit eine soziale und keine individuelle Eigenschaft. Dabei stellt der Elfmeterschuss keineswegs einen zu vernachlässigenden Spezialfall einer doppelten Kontingenz dar, sondern steht stellvertretend für Nullsummenspiele und damit für eine ganze Kategorie sozialer Interaktionen. Diese sind insofern von besonderem Interesse, als sich hier Akteure mit exakt gegenläufigen Interessen gegenüberstehen, die weder kommunizieren wollen noch können, jedoch interagieren und dabei eine stabile und vorhersagbare Form von sozialer Ordnung entstehen lassen. Und dies, obschon beide Akteure gerade kein Interesse an der Entstehung oder Aufrechterhaltung einer solchen Ordnung haben. Mit einigen Beispielen kann die soziale Relevanz dieser Form der doppelten Kontingenz ausgemessen werden: Das klassische Beispiel in der Literatur (vgl. z.B. Morgenstern 1976) ist die Geschichte»The Final Problem« von A.C. Doyle, in der sich Sherlock Holmes in einer ganzen Kaskade solcher doppelter Kontingenzen mit seinem Gegenspieler Professor Moriarty befindet. Solche Interaktionssituationen ergeben sich allgemein, wenn Ego Alter verfolgt und Alter genau dies zu vermeiden versucht, und zwar - wie die Beispiele zeigen - unabhängig davon, ob dies innerhalb eines normierten Rahmens geschieht oder nicht. So wird jeder Polizist (oder eine andere Sanktionsinstanz) versuchen, den Einbrecher (oder einen anderen Normbrecher) genau dort zu überraschen, wo dieser es nicht erwartet und jeder Einbrecher versucht, genau dies zu vermeiden. Dies gilt auch für kollektive Akteure, wie ein anderes Beispiel aus dem Bereich Fußball zeigt: Die Firma Adidas versuchte die Eigenschaften des von ihr für die Fußballweltmeisterschaft 2006 gefertigten Balls möglichst lange geheim zu halten und Nachahmerfinnen zu täuschen, um ihnen keine Zeit zu geben, bis zur Durchführung des Turniers ein gefälschtes Produkt auf den Markt zu bringen. Im Extrem findet sich diese Interaktionsstruktur auch bei strategischen Entscheidungen im Krieg, wie das Beispiel zeigt, das als »Battle of the Bismarck Sea« in die Literatur eingegangen ist (vgl. Rasmusen 1998, S. 19f).30 Die weitgehende Bestätigung der spieltheoretisch generierten Hypothesen anhand von Daten zu einer realen Situation doppelter Kontingenz ist deshalb ein starkes Argument für deren Anwendung auf das soziologische Kerngeschäft der Analyse von Interaktionen. Wie die vorgeführte Analyse klar zeigt, kann die dabei unterstellte Rationalität der Akteure nicht als irgendwie bewusstes, kognitives Abwägen interpretiert werden. 3 ! Vielmehr sollte Rationali- Die doppelte Kontingenz von Elfmeterschüssen 417 tät als die bisher fruchtbarste »als ob«-Heuristik betrachtet werden, die auf der Individualebene unterstellt werden kann, um auf der Aggregatebene korrekte Prognosen abzugeben. Rationalität ist dann nicht eine individuelle, sondern eine »ökologische« Eigenschaft der Interaktionsstruktur (vgl. Smith 2003, auch Becker 1962). Deshalb müssten die spieltheoretischen Hypothesen nicht nur für die bisher betrachteten, ausschließlich professionellen Spieler zutreffen, sondern auch für ungeübte Amateure, die sich in entsprechenden realen Interaktionssituationen befinden. Diese empirische Analyse steht allerdings bislang noch aus. Literatur Becker, G. S. (1962): Irrational Behavior and Economic Theory, in: Journal ofPolitical Economy 70, S. 113. Berger R. / Hammer R. (2007): Links oder rechts; das ist hier die Frage. Eine spieltheoretische Analyse von Elfmeterschüssen mit Bundesligadaten. Arbeitsbericht des Instituts für Soziologie der Universität Leipzig Nr. 47. Bloomfield R. (1994): Learning a Mixed Strategy Equilibrium in the Laboratory, in: Journal of Economic Behavior & Organization 25, S. 411-436. Brown 1. N. / Rosenthai R. W. (1990): Testing the Minimax Hypothesis: A Re-Examination of O'Neill's Game Experiment, in: Econometrica 58, S. 1065-1081. Chiappori, P.-A. / Levitt, S. / GroseclCJse, T. (2002): Testing Mixed-Strategy Equilibria When Players Are Heterogenous. The Case of Penalty Kicks in Soccer, in: American Economic Review 92, S. 1138-1151. Coleman, 1. S. (1986): Psychological Structure and Social Structure in Economic Models. in: R. M. Hogarth / M. W. Reder (Hrsg.), Rational Choice. The Contrast Between Economics and Psychology, London, S. 181-186. Coleman, J. S. (1990): Foundations of Social Theory, 2. Aufl., Cambridge-London. Diekmann, A. / Voss, T. (2004): Rational-Choice-Theorie in den Sozialwissenschaften, München. Dixit A. / Skeath S. (2004,): Games of Strategy, 2. Aufl., New York-London. Erev I. / Roth A. E. (1998): Predicting How People Play Games. Reinforcement Learning in Experimenta Games with Unique, Mixed Strategy Equilibria, in: American Economic Review 88, S. 848-881. Esser, H. (1991): Der Doppelpass als soziales System, in: Zeitschrift für Soziologie 20, S. 153-166. FIFA (Federation International de Football Association) (2005): Spielregeln 2005, Zürich Ganssmann, H. (2006): Double Contingency, in: J. Beckert / M. Zafirovski (Hrsg.), International Enc) clopedia of Economic Sociology, London-New York, S. 151-154. Johanni, S. / Tschacher, K. (2005): Ist der Elfmeter zu halten? Das Dilemma des Torhüters, mathematisc gesehen, in: uni.kurier.magazin der Friedrich-Alexander-Universität Erlangen-Nürnberg 106, S. 26-2: Kalter, F. (1999): Ethnische Kundenpräferenzen im professionellen Sport? Der Fall der Fußballbundesl ga, in: Zeitschrift für Soziologie 3, S. 219-234. Luhmann, N. (1988,): Soziale Systeme. Grundriß einer allgemeinen Theorie, 2. Aufl., FrankfurtlMain. 30) In dieser ModelIierung einer Seeschlacht des 2. Weltkriegs wählt der japanische Admiral dann den nördlichen Weg durch die Bismarck-See, wenn er erwartet, dass die amerikanische Flotte ihm im Süden auflauert, was diese veranlasst, doch nach Norden zu fahren, usw. usf. 31) Dies ist auch der Grund, wieso eine qualitativ-beschreibende Analyse von Elfmeterschüssen, wie sie etwa eine systemtheoretische Analyse der Situation nahe legen könnte, ohne soziologischen Erkenntnisgewinn bleiben muss. So ist das Unterfangen, die Sinnzuschreibung von Torwart und Schütze auf die Elfmetersituation oder deren Handlungsmotive zu rekonstruieren, zum Scheitern verurteilt, wenn damit die Absicht verfolgt wird, über individuelle ex-post Beschreibungen einer bestimmten historischen Situation hinauszugelangen (vgl. z.B. oben die Diskussion zu »Lehmanns Zettel«). Luhmann, N. (1973): Vertrauen. Ein Mechanismus der Reduktion sozialer Komplexität, Stuttgart. McKelvey, R.D. / Palfrey, T. / Weber, R. A. (2000): The Effects of PayoffMagnitude and Heterogenei on Behavior in 2x2 Games with Unique Mixed Strategy Equilibria, in: Journal of Economic Behavi & Organization 42, S. 523-548. Morgenstern, O. (1976): The Collaboration Between Oskar Morgenstern and John von Neumann on t Theory of Games, in: Journal of Economic Literature 14, S. 805-816. Moschini, G. (2004): Nash Equilibrium in Strictly Competitive Games. Live Play in Soccer, in: Econon Letters 85, S. 365-371. 418 Roger Berger und Rupert Hammer Nash, J. F. (1950): Equilibrium Points in n-Person Games, in: Proceedings of the National Academy of Sciences 36, S. 48-49. von Neumann, 1. (1928): Zur Theorie der Gesellschaftsspiele, in: Mathematische Annalen 100, S. 295320. Beobachtungen zwischen Funktionssystemen. Umweltdienstleistungsfirmen als intersystemische Organisationen Ochs, J. (1995): Games with Unique, Mixed Strategy Equilibria. An Experimental Study, in: Games and Economic Behavior 10, S. 202-217. Von Michael Guggenheim O'Neill, B. (1987): Nonmetric Test of the Minimax Theory of Two-Person Zerosum Games, in: Proceedings of the National Academy of Sciences 84, S. 2106-2109. Zusammenfassung: Wie verhalten sich Funktionssysteme zu Organisationen und wie können Organisationen Funktionssystemen zugeordnet werden? Die Systemtheorie ist diesbezüglich uneindeutig, widersprüchlich und kann wenig über Organisationen aussagen, die nicht einem Funktionssystem zugeordnet sind. Die Praxistheorie dagegen liefert dichte Beschreibungen, die theoretisch unterkomplex sind. Der vorliegende Aufsatz versucht die Defizite von Systemtheorie und Praxistheorie mit einer Typologie intersystemischer Organisationen zu beheben und eine genauere Beschreibbarkeit von Organisationen zu ermöglichen. Als Testbeispiel dient ein Typ intersystemischer Organisationen: Umweltdienstleistungsfirmen. Die Umweltdienstleistungsfirmen lassen sich anhand ihrer Organisationsstruktur, ihrer Publikationspraktiken und ihrer Forschungsbegriffe als vermittelnde und mehrdeutige intersystemische Organisationen beschreiben. Der Aufsatz versteht sich zudem als Beitrag zu einer Ethnographie intersystemischer Organisationen und wissensbasierter Dienstleistungen. O'Neill, B. (1991): Comments on Brown and Rosenthal's Reexamination, in: Econometrica 59, S. 503507. Parsons, T. / Shils, E.A. (2001 [Original: 1951]): Categories of the Orientation and Organization of Action, in: T. Parsons / E.A. Shils (Hrsg.), Toward a General Theory of Action. Theoretical Foundations for the Social Sciences, New Brunswick-London, S. 53-109. Parsons, T. / Shils, E.A. / Allport, G.W. / Kluckhohn, C. / Murray, H.A .I Sears, R.S. /Sheldon, R.C. / Stouffer, S.A. rrolman, E.C. (2001 [Original: 1951]): Some Fundamental Categories of the Theory of Action: A General Statement, in: T. Parsons / E. A. Shils (Hrsg.), Toward a General Theory of Action. Theoretical Foundations for the Social Sciences, New Brunswick-London, S. 3-29. Palacios-Huerta, I. (2003): Professionals Play Minimax, in: Review ofEconomic Studies 70, S. 395-415. Rapoport, A. / Boebel, R.D. (1992): Mixed Strategies in Strictly Competitive Games. A Further Test of the Minimax Hypothesis, in: Games and Economic Behavior 4, S. 261-283. Einleitung Rasmusen, E. (1998): Games and Information. An Introduction to Game Theory, 2. Aufl., Oxford. Rosenthai, R. W. / Shachat, J. M. / Walker, M. (2003): Hide and Seek in Arizona, in: International Journal of Game Theory 32, S. 273-293. Shachat,1. M. (2002): Mixed Strategy Play and the Minimax Hypothesis, in: Journal ofEconomic Theory 104, S. 189-226. Smith, V. L. (2003): Constructivist and Ecological Rationality in Economics, in: American Economic Review 93, S. 465-508. Vanderstraeten, R. (2002): Parsons, Luhmann and the Theorem of Double Contingency, in: Journal of Classical Sociology 2, S. 77-92. Varian, H. (1992): Microeconomic Analysis, 3. Aufl., New York-London. Walker, M. / Wooders, J. (2001): Minimax Play at Wimbledon, in: American Economic Review 91, S. 1521-1538. Dr. Roger Berger Dip!. Soz. Rupert Hammer Universität Leipzig Institut filr Soziologie Beethovenstrasse 15 04107 Leipzig [email protected] Eine Firma schreibt auf ihrer Homepage, dass sie »interdisziplinäre Umweltforschung« betreibe. I Die Firma verwendet Instrumente, Software, Methoden und Theorien, wie sie in unterschiedlichen wissenschaftlichen Disziplinen, von Soziologie bis zur Physik, angewandt werden. Sie publiziert jedoch kaum in wissenschaftlichen Zeitschriften, sondern schreibt Berichte für Auftraggeber, für die sie zum Beispiel Finanzierungsmodelle für den öffentlichen Verkehr evaluiert und FItisse zur ökonomischen und ökologischen Aufwertung modelliert. Die Firma beschäftigt als Projektmitarbeiter ausschließlich Personen mit Universitätsabschluss, einige davon mit Doktorat und Lehraufträgen an Universitäten. Wie soll man nun soziologisch solche Firmen beschreiben? Betreiben diese Firmen Wissenschaft? Soll man sie dem Wissenschaftssystem zurechnen? Oder handelt es sich dabei um Wirtschaftsorganisationen, die mit Wissen handeln? Eine Beschreibung solcher Firmen muss sich vor allem mit dem Problem funktionaler Differenzierung beschäftigen und mit der Frage, auf welcher Ebene funktionale Differenzierung beobachtbar ist. Bis dahin standen sich in dieser Frage eine empirieverliebte Praxistheorie und eine kommunikationszentrierte Systemtheorie unversöhnlich gegenüber. Beide Ansätze können jedoch theoretisch intersystemische Organisationen nicht adäquat beschreiben. Die Systemtheorie konzipiert Systeme als Kommunikationszusammenhänge und bleibt widersprüchlich, wie sich Organisationen zu Funktionssystemen verhalten, insbesondere, wenn sich Organisationen nicht einzelnen Funktionssystemen eindeutig zuordnen lassen. Die Praxistheorie sieht zwar diese Probleme, bietet jedoch theoretisch keine Alternative an, sondern belässt es bei der Feststellung, dass sich Organisationen Funktionssystemen nicht zuordnen lassen. Gerade intersystemische, d.h. nicht einem einzelnen Funktionssystem zuordenbare Organisationen bleiben dabei für beide Theorien theoretisch nicht fassbar. Dieser Aufsatz versucht die Defizite der beiden Theoriestränge mit einem Theoriemodell intersystemischer 1) Ich danke Monika Dommann und Jörg Potthast sowie den anonymen Reviewem für hilfreiche Kritik. Der Aufsatz beruht auf einem Forschungsprojekt »The Production of Socially Robust Knowledge«, das vom Schweizerischen Nationalfonds gefördert wurde. Eine ausführlichere Version des hier präsentierten Arguments findet sich in Guggenheim (2005). Soziale Welt 58 (2007), S. 419 -438 The Hinges of History: State-Making and Revolt in Early Modern France Author(s): Edgar Kiser and April Linton Source: American Sociological Review, Vol. 67, No. 6 (Dec., 2002), pp. 889-910 Published by: American Sociological Association Stable URL: http://www.jstor.org/stable/3088975 Accessed: 12/08/2010 07:22 Your use of the JSTOR archive indicates your acceptance of JSTOR's Terms and Conditions of Use, available at http://www.jstor.org/page/info/about/policies/terms.jsp. JSTOR's Terms and Conditions of Use provides, in part, that unless you have obtained prior permission, you may not download an entire issue of a journal or multiple copies of articles, and you may use content in the JSTOR archive only for your personal, non-commercial use. Please contact the publisher regarding any further use of this work. Publisher contact information may be obtained at http://www.jstor.org/action/showPublisher?publisherCode=asa. Each copy of any part of a JSTOR transmission must contain the same copyright notice that appears on the screen or printed page of such transmission. JSTOR is a not-for-profit service that helps scholars, researchers, and students discover, use, and build upon a wide range of content in a trusted digital archive. We use information technology and tools to increase productivity and facilitate new forms of scholarship. For more information about JSTOR, please contact [email protected]. American Sociological Association is collaborating with JSTOR to digitize, preserve and extend access to American Sociological Review. http://www.jstor.org THE HINGES OF HISTORY: STATEoMAKING AND REVOLT IN EARLY MODERN FRANCE EDGAR KISER University of Washington APRIL LINTON Princeton University The formation of early modern states-combining increases in taxation, warfare, and administrative centralization-was often violently opposed by subjects. A game theoretic model of strategic interactions between rulers and subjects is developed to more fully specify the relationship between state-making and revolt in France between 1515 and 1789. Quantitative analyses of revolts throughout France are combined with a brief case study of revolts in Guyenne (the most quarrelsome French province) to test propositions derived from the model. Offensive war (but not war in general) and administrative centralization increased the likelihood of revolt, while the presence of the Estates General (the national legislative assembly) decreased it. The effect of taxation on revolt depended on the historical context-high taxes and offensive wars tended to incite revolts prior to the Fronde (a cluster of revolts in 1648-1653), but had no effect afterwards. It is argued that the outcomes of significant revolts, like the Fronde, often serve as important turning points in the history of state-making. Potentially similar events in medieval England and early modern Spain are also discussed. HE PROCESS of early modem state- Imaking was often quite unpopular; it was marked by frequent wars, increasing taxation, and the growth and centralization of administrative institutions. As several scholars have shown, these factors often triggered revolts in early modern states (Barkey 1991; Berce 1987; Bonney 1978:214; Brustein and Levi 1987; Clark 1978; Goldstone 1991; Hopcroft 1999; Kiser, Drass, and Brustein 1993; Major 1960:127; Markoff 1996:12, 42; Mousnier 1970, 1979:741-42; Tilly 1975, 1986:7, 1993:17, 156-58; Zagorin 1982). We use a model of the strategic interactions between rulers and taxpaying subjects Direct correspondence to Edgar Kiser, Department of Sociology, Box 353340, University of Washington, Seattle WA 98195 (kiser@u. washington.edu). We thank Julia Adams, Terry Boswell, Julie Brines, Cai Yong, Jerry Herting, Peter Hoff, Hyojoung Kim, James Kitts, Becky Pettit, Kevin Quinn, Ron Schoenberg, Katherine Stovel, and several anonymous ASR reviewers for helpful comments. AMERICAN to explore the causal relationship between various aspects of state-making and tax revolts.' Both state-making and revolt are the result of choices, and these choices are always made in light of the anticipated reactions of other actors. Rulers consider the possibility of revolt when they think about raising taxes or pursuing unpopularpolicies. In deciding whether to revolt, subjects consider both the likelihood of rulers using repression and their other options for decreasing their tax burden,such as tax evasion. The determinants of the costs of tax evasion, in part a function of rulers' decisions about administrative techniques, must thus also be part of a model of revolt. To provide a rough heuristic model of the relationship between state-making and revolt, we use a game theoretic decision tree. 1 Revolts were caused by many factors other than taxation, including religious conflicts, population growth, price increases, elite conflicts, and the rise of capitalism (Barkey 1991; Goldstone 1991; Lachmann 1989, 2000). We focus only on revolts against state taxation. SOCIOLOGICAL REVIEW, 2002, VOL. 67 (DECEMBER:889-9 10) 889 890 AMERICAN SOCIOLOGICAL REVIEW The extensive form of game theory highlights the sequential nature of interaction, and thus precisely specifies the relationships between various aspects of state-making (war, taxation, and administrativecentralization) and revolt. We use the model in a limited way: We look at the state-making process from the point of view of subjects. Explaining the actions of rulers (such as tax increases and war-making) that initiate the process is beyond the scope of this paper.2 We test the relationship between aspects of state-making and revolt mainly via quantitative analyses of revolts in France between 1515 and 1789. Early modern France is a useful case in which to explore these relationships for several reasons. First, many of the classic historical studies of state-making and revolt cited above focus on this case, allowing us to draw on their insights in constructing our models and to compare their qualitative findings with our more quantitative results. Second, early modern France contains ample variation in the main aspects of state-making (levels of taxation, war, administrative centralization) and tax revolts, facilitating the testing of our arguments. Because tax rates and rates of revolt (among other things) varied substantially across provinces (Brustein and Levi 1987; Collins 1994:20; Major 1994:xviii; Markoff 1996:37; Mousnier 1979:641),3 it is important to supplement our analysis with an examination of these relationships at the provincial level.4 We focus on Guyenne, the 2An adequate test of the game-theoretic model as a whole would require both endogenizing the choices of rulers by explaining both tax rates and policy choices, and using comparative cases to show the conditions under which state-making goes down paths not followed in the French case. 3Although aggregated data on French taxation have been used as a measure of the tax burden in several exemplary historical analyses (Braudel 1972:684; Goldstone 1991:196-212; Mann 1993:358-400; Skocpol 1979; Tilly 1986:61-63; Wallerstein 1989), all of these scholars recognize that provincial variations across early modern France make incomplete any test that aggregates across them. 4 Our intent is not to reproduce Brustein and Levi's (1987) masterful analysis of the geography of revolt-an analysis of one province would not allow us to do that. We supplement their work by focusing on the timing of revolt. province in which revolt occurred most frequently in early modem France-almost onethird of the revolts in France occurred there. Guyenne is also a useful case because it allows us to explore in more detail the important fiscal and administrativechanges in the Pays d'Etat (provinces retaining provincial legislative assemblies in the sixteenth century) in southern France in the early seventeenth century. Because it is not possible to get quantitative data at the provincial level for our entire period (especially for tax rates, prices, and population), we do not reproduce our statistical analysis for Guyenne. However, we do have sufficient data to roughly test whether the same causal dynamics operate at national and provincial levels. STATE-MAKING AND REVOLT AS STRATEGIC INTERACTION We begin with two simple assumptions about the interests of actors.5The rulers (i.e., chief executives) of states want to maximize tax revenue while maintaining security of rule (Kiser 1994; Levi 1988; North 1981). Taxpayers collectively want public goods like security and social order that require taxation, but individually they want to minimize their tax burden.6Using these assumptions, and information and argumentsfrom the historical literatureto specify the structuralconditions within which these actors were embedded, we first outline propositions about how taxes, war, and centralization affected revolt in France, and then we construct a model showing how these factors are interrelated. TAXATION AND REVOLT Several scholars have argued that there is a relationship between levels of taxation and 5 The following discussion, based on these assumptions, outlines a stylized model of strategic interaction, and should not be taken as a historical description. 6 It is, of course, a simplification to group all taxpayers together, but the fact that most early modern tax revolts, in France and elsewhere, were class collaboration revolts involving a broad cross-section of subjects (Barkey 1991; Brustein 1985; Mousnier 1970:42) makes it a reasonable simplification. STATE-MAKING AND REVOLT IN EARLY MODERN FRANCE revolt frequency in early modern France (Barkey 1991; Berce 1987; Hopcroft 1999; Mousnier 1979; Tilly 1986; Zagorin 1982). Our model suggests that this relationship is produced by two micro-level causal mechanisms. Rulers will try to get as much tax revenue as they can without inciting revolts (because revolts threaten their security and are costly to suppress), and they will attempt to find nontax sources of revenue that will be less likely to instigate revolts. If rulers had perfect information about the probability of revolt at various levels of taxation, and if the costs of revolt were always greater than the benefits of tax increases, rulerswould always set taxes at the highest level that would not incite revolt and we would find no correlation between levels of taxation and revolt. First, however, rulers did not have perfect information, and thus would be expected to miscalculate in setting tax rates, thus sometimes triggering revolts.7 Second, even when rulers did have good information, there were some instances in which the gains from raising taxes or the costs of not doing so outweighed the costs of revolts, and rulers chose to increase taxes even if they thought revolt was a likely result. The most common early modem example is from international relations: Rulers could have an opportunity to begin or continue an unusually profitable offensive war, or fear a very costly invasion. Thus, for both of these reasons, we expect a positive relationship between levels of taxation and the frequency of revolts. WAR AND REVOLT Our primary argument about the effects of war on revolt is analogous to our argument about tax increases. Rulers want to pursue unpopularpolicies (those that serve their interests more than their subjects' interests), 7 Rulers would have to know the extent of the costs imposed on subjects by taxation (which will vary with population changes and the success of harvests), their military power relative to subjects, and the collective action capacity of subjects. Of course, as with rulers' decisions about increasing taxes and risking revolt, subjects' calculations that revolt will decrease taxes are made with incomplete information, and they are thus expected to miscalculate some proportion of the time. 891 but they realize that doing so can sometimes increase the likelihood of revolt. The lower the benefits to subjects provided by the current policy pursued by rulers (such as an unpopular war), the greater the potential benefit of a successful revolt that would alter or terminate that policy. This allows us to specify the relationship between war and revolt more precisely-it should depend on the type of war.8 Levi (1988, 1997) argues that citizens often view defensive wars as public goods from which they would benefit and thus for which they are willing to pay taxes, while they do not generally support offensive wars. Hopcroft (1999:82) suggests that this was true in early modem Europe. Although it is notoriously difficult to find reliable data on the perceptions of historical actors (Tilly 1975:9; Weber 1968:5-6), there is a great deal of evidence that subjects thought that offensive wars were less beneficial and legitimate than defensive wars. Offensive wars were often seen as enriching monarchs, but not their subjects, and were thus more difficult to justify (Klaits 1976:87-88; LeRoy Ladurie 1980:200; Rowen 1980; Seyssel [1519] 1981:130-31). The influential sixteenth century political philosopher, Claude de Seyssel ([1519]1981:130-31), argued that defensive wars were generally more legitimate than offensive wars and that the latter should only be initiated under certain limited circumstances. Klaits (1976:87-88) noted that of8There are two main bodies of work on the relationship between war and revolt-one is mainly quantitative and focuses on the nineteenth and twentieth centuries, and the second includes mainly qualitative historical analyses of the early modern era. In the quantitative literatureon modern states (see Stohl [1980] for a good summary), findings range from positive to negative relationships, with the majority of studies showing no strong relationship between the two. In contrast, almost all qualitative historical studies of early modern states suggest that war was a primary cause of revolts (Barkey 1991:703; Brustein 1985; Brustein and Levi 1987; Le Roy Ladurie 1980:292; Lublinskaya 1968:331; Pillorget 1975: 425-36; Tilly 1975, 1985, 1990, 1993). This raises an obvious question: Are the different findings in the two literatures due to differences in the time periods studied or differences in the methods used? A quantitative analysis of an early modern state should help us find the answer. 892 AMERICAN SOCIOLOGICAL REVIEW fensive wars had "ratherdubious legal foundations" and were thus frequently criticized in political pamphlets. Monarchs also seem to have been aware of this difference. In a discussion of offensive wars in his memoirs, Louis XIV ([1661-1668]1970) notes that he fears "being accused of recklessness when he rushes voluntarily into complications" (p. 123), although this fear was clearly not sufficient to stop him. We thus expect the relationship between war and revolt to be stronger for offensive wars than for defensive wars.9 ADMINISTRATIVE CENTRALIZATION AND REVOLT Subjects will choose to pay their full tax bill only when the options available to them to reduce or eliminate tax payments are more costly. Revolt is certainly the most risky and potentially the most costly strategy for subjects who want to decrease their tax burden. Therefore, subjects are expected to revolt only when the costs of their other options are prohibitively high. The most importantalternative available to subjects is tax evasion. Subjects can attemptto evade taxes, either by concealing taxable assets or by colluding with tax collectors (e.g., offering bribes for lower tax assessments).10 Tax evasion will 9 We also test an alternative argument about the relationship between war and revolt. States are often weak during wars, and thus more likely to be targets of revolt (Beik 1985:186, 196-97; Kiser et al. 1993; Tilly 1990:186, 1993:12). Subjects will only revolt when they think the probability of the ruler capitulating or unsuccessfully using repression is greater than the probability of rulers successfully repressing the revolt. This argument stresses the opportunities that war provides to potential rebels by temporarily shifting the balance of power in their favor, thus increasing the probability of a successful revolt. Like social movements (Tarrow 1998), revolts are thus expected to respond to shifts in political opportunity structures.The best indication of weakness is when a ruler's military resources are occupied elsewhere (e.g., in wartime). If this argument is correct, revolts will be more frequent during periods of warfare. l0 Another option is to exit the area being taxed, but this is prohibitively costly for subjects not living close to the border of another state (North and Thomas 1973). In fact, in the early almost always be preferable to revolt because it entails less cost and risk, does not require collective action, and provides clear tangible benefits in the form of lower tax payments. Therefore, subjects are expected to revolt more often when the costs of tax evasion increase. The costs of tax evasion depend primarilyon the effectiveness of rulers' tax administration apparatus. This is why both historians and sociologists argue that administrative centralization generated revolts (Barkey 1991:700, 708-09; Bonney 1978:214; Collins 1995:52; Mousnier 1970: 34, 38; Parker 1983:95; Westrich 1972:134; Zagorin 1982:215, 219). Because administrative centralization increases the effectiveness of assessment and collection, and thus also increases the costs of evasion (Matthews 1958:47; Mousnier 1979:611; Pillorget 1975:507-25), the greater the centralization of tax administration, the greater the expectedfrequency of revolt. THE HINGES OF HISTORY: TURNING POINTS IN STATE-MAKING AND REVOLT Neither rulers nor subjects can be expected to have perfect information about the relationship between tax levels and revolt, so many revolts will occur as a result of rulers' or subjects' miscalculations (see Gartzke 1999 for a similar argumentabout the causes of war). It is difficult to predict when such miscalculations will occur in historical analyses because it would require detailed knowledge of the information available to rulers at the time. However, we can predict that rulers will learn from past miscalculations, especially large miscalculations that had clear outcomes (Lublinskaya 1968:256). These events usually come in the form of major historical turning points (the "hinges" of history) in which the outcomes of revolts demonstrate to rulers (and subjects) either that future tax increases will not be beneficial for rulers (clearly successful revolts) or that revolting against taxes is likely to be an unsuccessful strategy in the future (clearly unsuccessful revolts). modern period it was very costly for most subjects, as 90 percent or more derived most of their wealth from land. Exit, thus, was not a viable alternative to revolt. STATE-MAKING AND REVOLT IN EARLY MODERN FRANCE 893 Recent developments in historical methods suggest that these turning points, critical junctures, or transformative events are important determinants of historical outcomes and are too often ignored in mainstream quantitative sociology (Abbott 1997; Collier and Collier 1991; Goldstone 1998; Issac and Griffin 1989; Mahoney 2000; Peirson 2000; Sewell 1996). Although researchers may use many different terms, all of their arguments suggest that key events can dramatically shift the trajectory of historical development. They also agree that these events can rarely, if ever, be predicted, but can be recognized by their consequences after the fact. Our argument focuses on the microfoundations of historical turning points. Historical turning points are important because they are likely to alter the structural factors affecting the cost-benefit calculations of actors, and thus (in this case) also affect the relationship between state-making and revolt. Focusing on potential turningpoints is one way to make quantitativesociology more historical (Issac and Griffin 1989). To begin we must first turn to the historical literature to identify them. Historians agree that there was such a turning point in early modern France-the relationshipbetween state-making and revolts changed following the collection of related revolts called the Fronde (1648-1653) (Collins 1995:77-78; Major 1994:xxi; Parker 1983:119; Westrich 1972: 140). As a result of both the information the Fronde provided about the relative power of rulers and subjects and the actions rulerstook in its aftermath(elaborated below), subjects viewed revolts as much more costly than before. Therefore, after the Fronde, we expect the relationship between taxation and unpopular policies (such as offensive war) and revolt to be much weaker than before. fensive war). Note that the "increase taxes" move also includes offensive war. We view these two moves as analytically similar-the tax rate specifies the costs to subjects, and the type of policy pursued determines the benefits. Throughout the game, subjects have three choices: pay, evade, or revolt (they are not entirely mutually exclusive, as subjects will generally choose some mix of pay and evade). If the ruler does not increase taxes, subjects will continue to choose some mix of pay and evade (depending on the costs of evasion), just as they did in prior years. (This assumes the conditions affecting the tax collection process do not change.) We call this situation a "customary taxation equilibrium." The more interesting developments follow from rulers' choices to increase taxes and pursue offensive wars, and these choices were the most common in early modern France. Subjects have the same three alternatives, but the payoffs for each are now quite different. The main effect of rulers choosing this strategy is to increase the costs of paying taxes or to decrease the benefits of the policies they fund. Therefore, both evasion and revolt become relatively more attractive.1 Subjects are expected to choose evasion more often (because it is less costly and less risky than revolt), but the frequency of revolt is expected to increase somewhat. The game then proceeds along two separate lines, depending on whether subjects choose to evade taxes or revolt. If subjects choose revolt, rulers then have to choose between using repression or giving in to subjects' demands and lowering the tax rate. If they lower the tax rate, the game ends with payoffs similar to the customary tax equilibrium. If they use repression, there is some uncertainty about the outcome-will they defeat the rebels or not? The role of chance A MODEL OF STA TE-MAKING AND REVOLT IISubjects may still choose to pay the tax, if the costs of evasion and revolt are too high. This leads to an upward spiral, as rulers again increase taxes. This is not a stable equilibrium. Eventually, the costs of paying will be higher than either evading or revolting. Subjects will then choose one of these two options, pushing them down to the lower branches of the game tree, as discussed below (indicated by dotted lines in Figure 1). Figure 1 outlines the state-making and revolt game, combining the factors we have discussed in a model of sequential, strategic decisions. Rulers move first and decide whether to keep the tax rate the same or increase it, and what policies to pursue (specifically, whether to initiate an unpopularof- 894 AMERICAN SOCIOLOGICAL REVIEW Co 0 co CLw cr n. w Era I~~~~~~~~~~~~~~~~~~~~C Co +L U) ~~~~~. - w ct ~ ~ L a 0~~~~~~~~~ U) -~~~~U)~ o k ~ L w ~~~~~~~~~~L a STATE-MAKING AND REVOLT IN EARLY MODERN FRANCE is capturedin game theory as a move by "nature"-either the repression is effective or it is not. If it is not, we return to something similar to the customary tax equilibrium. If it is successful, rulers are able to enforce the higher tax rate and their preferred policy choices. If subjects respond to tax increases or unpopular policies by increasing evasion, as we expect, rulers will attemptto increase the costs of evasion by centralizing administration. As with repression, there is an element of uncertainty regarding the outcome: Centralization may or may not be effective. This is again modeled as a move by "nature."If centralization is ineffective, the result is an outcome characterizedby high tax rates and high evasion, with a net effect similar to the customary tax equilibrium. If centralization is effective, subjects face high costs for both paying and evading. This is the situation in which their last-resort option, revolt, becomes most likely. Rulers respond to revolt either with repression or by conceding and lowering the tax rate. If they choose repression, it may or may not be effective (a move by "nature"as above). If it is not effective, the result is an unstable outcome characterized by high tax rates and frequent revolts. If it is effective, subjects will be forced to pay the higher tax rates and endure the unpopularpolicies chosen by rulers. We argue that this last outcome, a high tax equilibrium, is what eventually happened in early modem France. Rulers often chose to increase taxes and fight unpopular offensive wars, especially in the seventeenth century. Subjects sometimes revolted, but most often increased their tax evasion. Rulers responded by centralizing, primarily with the use of intendants. This centralization was in part successful, and when it increased the costs of evasion, revolts became much more common, culminating in the largest revolt of all, the Fronde. Rulers successfully used repression against this revolt (and co-optation after it), thus convincing subjects that future revolts would be unlikely to succeed. The result was a high tax equilibrium after the Fronde, as French rulers were able to raise taxes and fight offensive wars with little resistance from their subjects. Our quantitative analy- 895 Table 1. Description of Variables Used in the Analyses: Tax Revolt Initiations in France, 1515 to 1789 Variable Mean S.D. Tax revolt initiation (1 = yes) .11 Total tax per capita (in 100,000 it.) 5.06 Range 0-1 4.46 .87-37.12 Before and during the Fronde(1 = yes) .51 Administrativecentralization (1 = 1642 on) .53 - 0-1 Estates General (1 = yes) .37 - 0-1 Warin progress (1 = yes) .65 0-1 Defensive war in .34 0-1 .50 0-1 0-1 progress (1 = yes) Offensive war in progress (1 = yes) ses and provincial case study provide tests of many of the links in this causal chain.'2 DATA AND MEASURES Table 1 describes the variables corresponding to the empirical expectations discussed above, and Appendices A and B list the dates of all revolts and wars. Measures of the independent variables are lagged to assure the proper temporal order in our findings. The descriptive statistics in Table 1 document several interesting features of early modem Frenchhistory. The French state was forged by force, both internally and externally. Revolts were relatively frequent events, taking place in about 20 percent of the years between 1515 and 1789. They were initiated in about 11 percent of these years (see Appendix A). Wars were in progress during about 65 percent of the years during this period. Offensive wars were somewhat more common than defensive wars-France was involved in offensive wars in about 50 percent of the years, and in defensive wars in about 34 percent. 12Unfortunately,we cannot test all of the links, due to lack of data. There are no systematic data on tax evasion, for example. 896 AMERICAN SOCIOLOGICAL REVIEW REVOLTS Our dependent variable is "tax revolt initiation." Coded dichotomously, it marks the beginning of one or more tax revolts in a particularyear.'3The data are compiled from Heller (1991), Kiser et al. (1993), and Tilly (1986, 1993). We include what Tilly (1993) calls "revolutionarysituations,"in which the rebels held considerable instrumentsof state power, as well as regional events that he designates as "serious tax rebellions." These insurrections "stemmed from essentially the same processes" (Tilly 1993:156).14 Both shared the same objective-to lessen the tax burden-and entailed similar risks. They often cost thousands of lives. TAXATION Due in part to fires in the treasury archives, and in part to poor record-keeping by the monarchy, data on taxation in early modem Franceare incomplete and sometimes unreliable. Historians give very different estimates of the tax revenues in a particular year-a "reason for considerable caution" (Rasler and Thompson 1989:133). Thus, it is essential to know the literaturewell so as to make wise choices among conflicting figures. Our estimates of gross total taxation drawheavily on research by Guery (1978), Hoffman (1986, 1996), and Rasler and Thompson (1989).15 To arrive at a total tax amount for each year, it was sometimes necessary to ex13 In some cases, more than one revolt started in the same year (see Appendix A). An analysis in which revolt initiation is coded as the number of revolts beginning in a given year yields results that are substantively similar to the ones we report. 141 In earlier analyses, we found that coding revolt initiation according to revolt severity did not meaningfully alter our findings. 15 Direct taxation in early modern France took two main forms: the taille, levied on property, and capitation, levied on individuals. Collins (1988), Clamageran (1980), Lewis (1968), and Morineau (1968) offer considerable data on both of these. Indirect taxes primarily include a variety of tariffs such as the gabelle, a salt tax; aides, a tax levied on the consumption of a variety of products; and traites, duties paid when merchandise was imported and/or sold. trapolatebased on the data at hand. We have done this by (1) subtracting nontax revenue (revenue from crown lands and the sale of offices) from the total revenue figure for a given year, (2) aggregating data on all revenues contributing to total tax, or (3) carrying established figures from year to year. Because we are interested in measuring the real tax burden that French citizens bore, we express taxation in terms of livres tournois (1.t.) per capita.'6 Ideally, we would include in our models a control for both real wages and taxpayers' other main expenses (such as rents and tithes), but we lack reliable and comprehensive data on these factors during the early modem period.'7 HISTORICAL TURNING POINT: THE FRONDE The Fronde was a large-scale set of revolts with a very clear outcome. The crown emerged victorious and the state subse16 The population of France increased by over 10 million during the time span considered here. Dupaquier (1979) is our principal source of population data. We also use estimates by Bean (1973), Bonney (1979), and Wilson and Parker (1977). When yearly estimates were unavailable or contradictory, we smoothed the data between benchmark figures, allocating an average rate of population increase/decrease per year (cf. Goldstone 1991). 17 To explore the possibility that tax revolts really reflected a more general resentment toward rising costs or shortages, we tested models including (1) the price of wheat, and (2) a standardized tax variable that reflects the amount of wheat, in setiers (a common measure of grain that ranged in volume from 150 to 300 liters), that could be purchased with the per capita tax revenue for a given year (Baulant 1968). The wheat price variable was never significant, even with per capita tax absent from the model. The results of models with standardized tax are very similar to those we report in Tables 1 and 2, although overall model fit was poorer. We also investigated the possibility that subjects responded to nominal tax increases more than to the level of taxation (Goldstone 1991; Le Roy Ladurie 1980:263). The annual percent change in nominal or standardized taxes was never significant. This finding, however, does not conclusively discredit the proposition that tax increases prompted revolts-to do so would require additional case studies, preferably with better data. STATE-MAKING AND REVOLT IN EARLY MODERN FRANCE quently became stronger and more centralized (Hoffman 1994:247; Mousnier 1979: 571, 624). Tilly (1986) argues that the "midseventeenth century served as a hinge in the history of contention" (p. 40). In the aftermath of the state's "military victory" in the Fronde (Mousnier 1979:624; also see Lachmann and Adams 1988:154), several changes increased the power of the state relative to potential rebels. After the Fronde, a new law was passed confiscating half of town revenues for the central state, and intendants took more direct control of town spending (Berce 1987:16-17; Doyle 1996:19; Mousnier 1979:572). Town walls also atrophied after the Fronde. Towns expanded; tree-lined streets replaced old moats; rings of boundary stones replaced town walls (Berce 1987:54-55). Subjects lost power in judicial institutions that had been used to spreadinformationabout crown policies contrary to their interests. Moote (1971) argues that the limitation of the right of remonstrance in law courts (parlements) until after laws had been registered was "by far the most successful aspect of the continuing royalist revival after the Fronde" (pp. 356-57). Localities and provinces lost an important political tactic, substantial revenue, and the ability to defend against royal attacks. The development of a standing army also increased the costs of revolt by making quick repression more likely (Ranum 1993:346). In these ways, the Fronde "extinguished local resistance to the fiscal offensive of the crown" (Berce 1987:17; also see Parker 1983:119; Pillorget 1975:900-10). The aftermath of the Fronde was marked not just by repression but by concessions and co-optation as well (Lachmann and Adams 1988; Tilly 1986:40), and this too made revolt less likely. Opposition to the state was "subdued but not eradicated" after the Fronde (Moote 1971:355). Therefore, Louis XIV and subsequent rulers had to learn how to compromise (Mettam 1988:3-4, 11-12). They were more careful not to disrupt traditional privileges, and they provided additional lucrative state jobs to those elites whose supportthey required (Lachmann and Adams 1988:155-58). As our argument suggests, the one important result of this clear state victory, coupled with co-optation, is that potential rebels 897 learned that revolt was likely to be unsuccessful, so they shifted to more cautious and covert forms of disobedience (Mettam 1988:3-4, 11-12; Parker 1983:102-03).18 Because the crown emerged victorious and the state subsequently became stronger and more centralized, it is probable that the Fronde altered the relationship between state-making and revolt. We therefore include a variable coded 1 for the years before and during the Fronde (1515-1653), and 0 for the years thereafter. ADMINISTRATIVE CENTRALIZATION Direct tax collection in early modern states was generally decentralized. In almost all states, taxes were assessed and collected by officials elected or appointed and controlled locally, not by the central state. France was no exception. Rulers generally negotiated lump sum payments from regions and towns, and left it to the locals to collect these taxes as they saw fit (Markoff 1996:237). Although direct tax collection was never fully centralized in early modern France (even the revolution did not totally change this), there was a major turning point in the seventeenth century: the use of intendants (Kettering 1986:6). Parker(1983) notes that intendants were the "principalagent through which the concentration of authority was effected" (p. 81; also see Collins 1995:53). The intendants were part of a long list of royal attempts to use ad hoc commissioned officials, centrally appointed and controlled, to supervise local tax collection (dating back to the medieval bailiffs). Although Richelieu used intendants, their numbers and their powers were significantly increased in 1642, when they were given full authority to supervise tax collection (Bonney 1988:82). This was the most important administrative transformation in direct tax administration prior to the revolution, so we include a dummy variable for "administrative centralization" to capture this shift. 18 Tilly (1993) remarks that post-Fronde revolts were different in substance from earlier uprisings. Although nominally still tax revolts, they were more importantly protests against "the expense, arbitrariness, and corruption of the government"(p. 163). 898 AMERICAN SOCIOLOGICAL REVIEW WARS Our war data come from Kiser et al. (1993, 1995), with additions for the eighteenth century from Dupuy and Dupuy (1977) (see Appendix B). The war variables are dichotomous. A value of 1 indicates that the state was involved in a conflict during a given year; a value of 0 for war or for both offensive and defensive war means that no war took place. This allows us to assess the general relationship between war and revolt initiation, as well as to contrast the impact of defensive and offensive wars. NATIONAL AND PROVINCIAL REPRESENTATIVE INSTITUTIONS AS CONTROL VARIABLES Subjects can attemptto negotiate with rulers collectively to lower their tax obligations or to modify policies, usually throughrepresentative political institutions. There are two contrasting arguments about how the presence of representative institutions might affect revolt. First, they were important sites for the exchange of informationbetween rulers and subjects (Mousnier 1979:215). By increasing the flow of information between parties, they could decrease the level of uncertainty and thus decrease the frequency of revolt. Second, however, representative political institutions could enhance the collective action capacity of subjects and thus increase the frequency of revolt (Bonney 1978:347-48; Brustein and Levi 1987).19 19Collective action capacity is important, but the main question involves the level at which these institutions are most effective. Is it the country as a whole (Estates General), provinces (provincial estates), parishes (ad hoc meetings of groups of communities), or local communes? Until its demise in 1614, the Estates General intermittently brought together representatives from all over France. It served as a viable forum for negotiation about taxes (Mousnier 1979:215; Parker 1983:81), but was probably too large and heterogeneous to facilitate collective action, which was almost never organized at the level of the country as a whole. Provincial estates, which existed (decreasingly over time) in some regions but not others, were forums for negotiation (Collins 1994:23; Hoffman 1994:230; Mousnier 1979:610), but may also have been too large to facilitate collective action. We suspect that lo- Both of these possibilities, pushing in opposite directions, are consistent with the microfoundations of our model. We thus have no clear prediction about the effects of representative institutions; it will depend on which effect is stronger.We include both national and provincial representative institutions as control factors. The broadest of these institutions was the Estates General, a national legislative assembly comprised of representatives of the clergy, nobility, and the primarily bourgeois "third estate." It met intermittently until 1614, consulting kings on importantmatters such as war and taxes, and presenting lists of grievances. We therefore include a dummy variable for the existence of the Estates General, coded 1 prior to 1615, and 0 after that. We also explore the role of the provincial estates, even though we cannot include them in our regression analyses. In Table 4, we note, by region, whether a provincial estate existed when revolts were initiated. We discuss the effects of provincial estates along with our regression results. DATA ANALYSIS AND RESULTS REVOLTS IN FRANCE: REGRESSION ANALYSES Some degree of autocorrelation is common in time-series analysis. The logit regression model does not provide for unmeasuredfactors affecting the occurrence of revolts, nor does it allow for possible serial correlation due to the dependence of the observations. While this means that the estimates of the coefficients are not efficient, they are consistent (Robinson 1982). For statistical inference we use QML (quasi-maximum likelihood) standarderrors, which are consistent under misspecification of the model cally based institutions were more important determinants of collective action capacity. Berce (1987:75-76) stresses the importance of collective action at the parish level, with several communes (usually led by local notables) assembling to discuss shared interests, including possible revolts. Unfortunately, systematic data on the power and activities of these assemblies at the parish and commune level are not available for this period, so we cannot add this as a variable in our quantitative analyses. STATE-MAKING AND REVOLT IN EARLY MODERN FRANCE 899 Table 2. Logit Coefficients from the Regression of Tax Revolt Initiation on Selected Independent Variables: France, 1515 to 1789 IndependentVariable Total tax per capita (in 100,000 i.t.) (lagged one year) Model 1 Model 2 -.114* (.049) Before and duringthe Fronde 1.296** (.450) Model 3 Model 4 -.249 (.275) -.062 (.134) -1.407 (.310) .710* Before and during the Fronde x total tax per capita (.310) 1.852* Administrative centralization (lagged one year) Constant AIC 2.532** (.864) (.845) -1.161*** (.266) 180.35 -2.914*** (.388) 175.89 -1.107 (1.724) 157.75 -4.060*** (.984) 165.89 Note: N = 275 for each model. QML standarderrorsare shown in parentheses. *** < .001 (two-tailedtests) ** <.01 *p<.05 (Arminger 1995; Gourieroux, Monfort, and Trognon 1984; White 1982).20 The AIC (Akaike information criterion) fit statistic provides an accounting of use of degrees of freedom, and is especially useful when comparing nonnested models such as these. Comparatively small values indicate an improvement in fit. The models in Table 2 test the degree to which the level of taxation, the Fronde, and administrative centralization influence the likelihood of revolt initiation. By itself, the level of taxation is negatively related to revolt initiation (Model 1). Taxes were highest in the eighteenth century; revolts were least frequent then. Models 2 and 3 incorporate a dummy variable for the period before and during the Fronde-alone and in interaction with taxation. Model 3 specifically examines the effect of the Fronde on the relationship between taxation and revolt initiation. The impact of taxation on the probability of revolt is positive before and during the Fronde, whereas after the Fronde it is not significant. This finding demonstrates quantitatively what many historians have argued-that the Fronde was indeed a key turning point in 20 We also rana modelof revoltinitiationthat includeda laggeddependentvariable(revoltinitiationin thepreviousyear),andfoundverysimilar results. The lag did not contributesignificantlyto any of ourmodels. French history which changed the relationship between state-making and revolt (Collins 1995:77-78; Major 1994:xxi; Mousnier 1979:571, 624). This is easy to see graphically as well; although the Fronde divides the period covered in our study almost exactly in half, there were more than three times as many revolts prior to its conclusion than after it. As we argued above, the decisive defeat of the rebels signaled to all subjects that revolts were unlikely to be successful strategies for opposing taxation (Berce 1987:17; Mettam 1988:3-4, 11-12; Pillorget 1975:900-910). After the Fronde, rulers in France were able to raise taxes without fear of revolt. Model 4 incorporates administrative centralization after 1642. Here it appears that both the period before and during the Fronde and the years of direct tax centralization were times in which revolts were likely to begin. Ten revolt initiations-a third of the total-occurred in the years for which positive values for these variables overlap: 1643 through 1653. In substantive terms, this effect is explained by opposition to the use of intendants, central semibureaucratic royal agents that increasingly intervened in direct tax administration, eliminating some forms of local corruption that had benefited subjects at the expense of the monarch (Mousnier 1979:611; Pillorget 1975:50725). There is thus some supportfor the argu- 900 AMERICAN SOCIOLOGICAL REVIEW Table 3. Logit Coefficients from the Regression of Tax Revolt Initiation on Selected Independent Variables: France, 1515 to 1789 Model 1 Model 2 Model 3 Model 4 Model 5 -.185 Total tax per capita (in 100,000 It.) (lagged one year) (.168) .022 (.115) -.013 (.107) -.081 (.107) -.23 (.221) Before and duringthe Fronde .168 (.963) 1.487 (.814) -.853 (1.071) 1.531* (.730) IndependentVariable 1.732* (.768) -2.497*** Estates General -2.233*** (.639) War in progress (lagged one year) (.693) 1.984** (.661) Defensive war in progress .647 .659 .198 (.409) (.431) (.435) Offensive war in progress 1.378** -.541 1.131* (lagged one year) (.507) (.758) (.581) (lagged one year) Before/during the Fronde 2.910** x offensive war in progress (1.006) Constant -1.516 (1.201) -4.787*** (1.113) -4.085*** (.999) -2.268** (.962) -2.109 (1.253) AIC 151.08 156.89 156.22 145.90 140.82 Note: N = 275 for each model. QML standarderrorsare shown in parentheses. *p <.05 ** < .01 *** < .001 (two-tailed tests) ment that administrative centralization was an additional aspect of state-making that stimulated revolts, but its effect is temporally limited. The models in Table 3 explore the effects of representativeinstitutions and wars on the probability of revolt. The odds of a revolt initiation were almost 50 percent lower in years when the Estates General convened. In Model 1, both a restraining effect of the Estates General and a positive before/duringthe-Fronde effect are prominent. Half of the revolt initiations that we consider occurred between 1616 and 1653-years before or during the Fronde, but after the Estates General ceased to meet. Including both "before and during the Fronde" and "Estates General" markers in the same model (Model 1) effectively shows that, although revolts were much more likely to take place before or during the Fronde, this was not the case when a central legislative body existed and met. This finding suggests that the Estates General worked not as a collective action mechanism facilitating revolt, but as a forum for negotiation and information exchange that provided a less costly alternative to revolt. Although we could not include provincial estates in our regression analyses, we did gather data to assess their effects on revolt (see Table 4). Our data neither support our argument that their presence decreased revolts, nor Brustein and Levi's (1987) contention that they facilitated revolt. Rather, we find no significant difference in revolt initiation across provinces with and without provincial estates, or across time in areas where provincial estates met during only some of the years from 1514 to 1789. Table 4 shows that 17 tax revolts occurred in provinces where and at times when provincial estates met, whereas 18 took place where or when they did not. When we compare blocks of total province-years in which provincial estates met (3,544 years) and did not meet (7,681 years), we see that revolt initiations happened .46 percent of the time in the first block of years and .23 percent of the time in the second. Revolts thus seem to be slightly more likely when provincial estates were present, thus providing a bit more support for Brustein and Levi's view than for ours, but the difference is too small to be substantively significant. STATE-MAKING AND REVOLT IN EARLY MODERN FRANCE 901 Table 4. Provincial Estates and Revolts by Province: France, 1514 to 1789 Revolt Initiations Province Anjou Auvergne Bearne Berry Bigorre Boulonnais Bourbonnaise Bresse Brittany Burgundy Champagne Dauphind Foix Gavardan Guyenne he de France Ile de R6 Ile d'Oleron Labourd Languodoc Limosin Maine Marche Marsan Metz Navarre Nebouzan Nivernais Normandy Orleanais Picardy Poitou Provence Quatre-Vallees Saintonge Saumurois Soissonnais Soule Toul Touraine Verdun Total Provincial Estates No No Yes No Yes until 1622 Yes No Yes Yes Yes No Yes until 1628 Yes Yes until 1622 Yes until 1622 No No No Yes until 1622 Yes No No No Yes until 1622 No Yes Yes until 1622 No Yes until 1655 No No No Yes Yes until 1622 No No No Yes until 1622 No No No Numberof Years Numberof Years Provincial ProvincialEstates EstatesMet Did Not Meet When When EstatesDid EstatesMet Not Meet 0 0 275 0 108 275 0 275 275 275 0 114 225 108 108 0 0 0 108 275 0 0 0 108 0 275 108 0 141 0 0 0 275 108 0 0 0 108 0 0 0 275 275 0 275 167 0 275 0 0 0 275 161 0 167 167 275 275 275 167 0 275 275 275 167 275 0 167 275 134 275 275 275 0 167 275 275 275 167 275 275 275 0 0 3 0 0 1 0 0 2 0 0 0 0 0 5 0 0 0 0 4 0 0 0 0 0 0 0 0 1 0 0 0 1 0 0 0 0 0 0 0 0 1 0 0 0 0 0 1 0 0 0 0 0 0 0 7 1 0 0 0 0 1 0 0 0 0 0 0 0 0 1 0 4 0 0 2 0 0 0 0 0 0 3,544 7,681 17 18 902 AMERICAN SOCIOLOGICAL REVIEW Getting back to Table 3, Models 2 and 3 contrast two ways of measuring war.21 Model 2 considers all wars together; Model 3 separates offensive and defensive wars. Although the general war variable has the expected effect, comparison reveals that the type of war is of crucial importance: Offensive wars were responsible for the positive effect of war on revolt initiation. This test allows us to adjudicate between the three possible causal mechanisms linking war to revolt. It seems clear now that the relationship between war and revolt was not entirely due to the costs of war. Although we unfortunately have no data on the costs of each war, there is no reason to expect offensive wars to be significantly more expensive, and this would be accounted for by the tax variable in any case. Nor is the relationship due only to the weakening of the state due to war, because if anything, defensive wars might be expected to weaken the state more (Tilly 1990:186; 1993:12). The strong effect of offensive war in Model 3 suggests that subjects cared about how their tax money was spent. They were willing to pay for defensive wars that protected them from external threats, but not for offensive wars from which they expected few if any benefits and could pay very high costs (Hopcroft 1999; Klaits 1976:87-88; Rowen 1980; Seyssel 1981:130-35). They seem to have thought that defensive wars were public goods, but that offensive wars served narrower interests (Levi 1988, 1997). Of course, it would take a detailed cultural analysis of subjects' reactions to different types of wars to fully demonstrate this, and that is beyond the scope of this paper.22 21 TheFrondevariableapproachessignificance in thesemodels(p = .080 in Model2 and.068 in Model5). 22 Buena de Mesquita, Silverson, and Woller (1992) report that the outcome of wars, in conjunction with who initiated them, has a strong effect on revolt. We tried a fourfold differentiation like theirs: successful offensive wars, lost offensive wars, successful defensive wars, lost defensive wars. We found, however, that whether an offensive (or defensive) war was won or lost did not change the relationships we report. Variables that reflect outcome were nonsignificant in our models. Model 4 tests the proposition that the relationship between offensive wars-an unpopular policy-and revolt was weaker after the Fronde. Indeed, we find that offensive wars affect the likelihood of revolt only in the period before and during the Fronde. Model 5 best fits the observed pattern of revolt initiations.23It accounts for the combined effects of taxation, the Fronde, the Estates General, and wars. Here we see clear evidence of the multiple causal mechanisms linking state-making and revolts. Tax revolts were not simply a response to high taxes; they were facilitated or hindered by other factors that are key to the state-making process-notably offensive wars and the presence or absence of representative institutions. A PROVINCIALCASE STUDY: REVOLTS IN GUYENNE Figure 2 shows the geographic distribution of tax revolts in France in three periods: the reign of Francis I (1515-1548), the period between the death of Francis I and the beginning of the Fronde (1549-1648), and the years during and after the Fronde (16491789). In the first period, all of the revolts occur in the south and southwest. The two later periods show more geographical variation, although most revolts are still found in the south and southwest. This pattern has been documented and explained by Brustein and Levi (1987) and Hopcroft (1999). Although our focus is on temporal variation, the geographic concentration of revolts in southern and southwestern France suggests that it would be wise to look more closely at these areas to provide an additional and more precise test of our arguments. We selected the province with the highest rate of revolt in France, Guyenne -12 of the 36 tax revolts in early modern France occurred in this southwestern province. Guyenne was part of the dramatic change in the status of the Pays d'Etat in the seventeenth century, involving increases in taxation and centralization, and diminishing or 23 The fit is significantlybetter than that of modelsin whichtax centralizationis substituted for the EstatesGeneralvariable. STATE-MAKING AND REVOLT IN EARLY MODERN FRANCE 903 * ~~~~~~~~~* f~~~ * f * 1514-1548 * Figue 2 *+*i * R* Figure 2. Tax Revolt Initiations in France, 1515 to 1789 eliminating the provincial estates.24Prior to the seventeenth century, Pays d'Etat generally had more autonomy from the crown, both legislatively (through provincial estates) and administratively,which usually allowed them to minimize their tax burden relative to the more centrally controlled Pays d'IElection.25This began to change between 24 Le Roy Ladurie (1980:201) argues that the general factors causing revolts were similar throughout southern France, and historians discussing the southern provinces mention the same factors we have discussed for France as a whole-taxes, war, centralization, the role of provincial estates, and changes brought about by the Fronde (Beik 1985; Collins 1994; Le Roy Ladurie 1980:198, 201-202, 286; Major 1966; Mousnier 1979:622-23; Westrich 1972; Wolff 1969:210, 230). 25 The assault on the Pays d'Etat did not affect all provinces equally. Guyenne was a relatively rich province (as indicated by high levels of meat consumption [Ranum 1993:217-18]), known then and now primarily for the export of great wine (Bordeaux). In part because its wealth made 1549-1648 * 1649-1789 ** D A about 1620 and 1670 (Collins 1988:105), in what Major (1994) calls a shift from a "renaissance monarchy" to an "absolute monarchy." Tax increases were thus a key component of this transformation. As Collins (1994) puts it, "[K]ings saw the Pays d'Etat as an untapped (or poorly tapped) financial resource. After 1628, [Louis XIII] dramatically raised taxes in all of them" (p. 152). Although precise data are not available, the significant tax increases that hit all of the Pays d'Etat began in Guyenne in the 1620s (Ranum 1993: 220). To increase taxes, the administrative and legislative autonomy of the Pays d'Etat were decreased, and in some cases terminatedentirely (Barkey 1991:702). The process of administrative centralization (imposition of intendants) was complicated in Guyenne. Init an appealing place for monarchs to look for more revenue, Guyenne was hit especially hard, losing its Pays d'Etat status (Languedoc, for example, retained that status). 904 AMERICAN SOCIOLOGICAL REVIEW tendants were imposed, abolished, and then re-imposed several times between 1616 and 1653 (after which they remained in place).26 The elimination of representative institutions mattered less is Guyenne than elsewhere. Even when it was a Pays d'Etat, the provincial estates were always weak in Guyenne and were virtually eliminated after 1621 (Collins 1994:154; Major 1966:369; Parker 1983:81).27 With these rough measures of our independent variables at the provincial level, we can now explore their effects on revolts in Guyenne. Taxes alone had little effect-revolts were instigated in 4.7 percent of the years prior to the major increases in 1623 and in 4.2 percent of the years after those tax increases. However, just as for France as a whole, adding the turning point of the Fronde clarifies the relationship between taxation and revolt. Revolts were three times as likely in Guyenne before the Fronde, and tax increases before the Fronde were over five times as likely to cause revolts as were tax increases after the Fronde (13 percent of years with tax increases resulted in revolts before the Fronde, compared with only 2.2 percent after the Fronde). The effects of administrative centralization on revolts are similar-they too are highly conditioned by the Fronde. In the preFronde period, the imposition of indendants more than doubled the likelihood of revolt initiation (revolts startedin about 13 percent of years with intendants but in less than 5 percent of years without intendants prior to the Fronde in Guyenne). Just as it did with tax increases, the Fronde virtually eliminates the relationship between administrativecentralization and revolt-the use of intendants is more than five times more likely to produce revolt before the Fronde as after it. War had a very strong effect on revolt in Guyenne-11 of the 12 revolts in Guyenne were initiated during a French war. Revolts 26 Intendants were present in Guyenne in 1616, 1619, 1622-1625, 1627-1628, 1630-1648, 1650-1651, and 1653-1788. 27 The estates in Languedoc, for example, were always more powerful and met more frequently. But although they survived the onslaught on the Pays d'Etat, they were weakened substantially after 1663 (Hoffman 1994:230, 241; Major 1994: 346-47; Mousnier 1979:610-23). were initiated in roughly 8 percent of years experiencing warfare, but in less than 1 percent of the peaceful years. Revolts were slightly more likely to occur during offensive wars, but that effect is not strong. Revolts were initiated in about 5 percent of years with offensive wars, and in 3.6 percent of years in which France was fighting a defensive war. The presence of representativeinstitutions had no effect on revolt in Guyenne. Neither the Estates General nor the provincial estates affected revolt initiation. (Because the provincial estates were always weak in Guyenne [Major 1966], we would not expect them to affect revolts.) Overall, our results at the provincial level are similar to those for France as a wholetaxation, administrative centralization, and war (especially offensive war) are important causes of revolts, and the effects of the first two factors interact strongly with the Fronde. Because these results are based on only a few cases (12 revolts) and very rough measures of some of our causal factors (i.e., taxation), we cannot make any strong conclusions based on this analysis of Guyenne. However, its consistency with our nationallevel findings provides good evidence for the robustness of our conclusions. CONCLUSION We model the relationship between statemaking and tax revolt as the product of strategic interactions between rulers and subjects. Both groups are making cost-benefit calculations in which an important part of the decision-making process is their anticipation of the actions of others. Neither rulers nor subjects have perfect information, so both are expected to miscalculate sometimes. However, both are also expected to learn over time, especially when outcomes are clear and decisive, so experience should lead to fewer miscalculations.28 28 We do not want to overstate the extent of learning in this case. Although rulers did have some information about the policies of prior rulers (and reactions to those policies), Peirson (2000) is correct to note that learning is more difficult in the context of political institutions than in the context of markets. STATE-MAKING AND REVOLT IN EARLY MODERN FRANCE We find that the three main aspects of early modern state-making-war, tax increases, and administrative centralizationall incited tax revolts in early modern France. However, in each case, our findings show that these relationships are complex and often contingent on other factors. Our initial analyses show an effect of war on revolt, but this effect operates only through offensive wars. When we decompose wars into offensive and defensive types, our quantitativeresults show that only offensive wars consistently generated revolts. Our provincial analysis of Guyenne also shows a slightly stronger effect of offensive wars. This is consistent with our hypothesis, but the effect is stronger than we anticipated. The opportunity for revolt (based on the weakness of the state) was clearly not all that mattered-subjects primarily reacted to how their tax money was being spent. When wars were fought to defend them, subjects were more willing to pay; when rulers pursuedoffensive wars that seemed to provide few benefits, subjects frequently revolted. As Levi (1988, 1997) argues, subjects' compliance is in part a function of whether they think the state is providing them with public goods or not. These findings help us explain the difference between the strong effects of war on revolt found in most qualitative studies of early modern states and the weak effects found in quantitative studies of the nineteenth and twentieth centuries. Our quantitative analysis reinforces the qualitative findings for early modern states, and suggests that the early modern period is indeed different-that it is thus necessary to specify a scope condition for the relationship between war and revolt. Perhaps the relationship between warfare and revolt changes with the advent of nationalism in the nineteenth century (Hechter 2000). When "subjects" are transformed into "citizens" with some stake in the wars of "their"country, a "rally 'round the flag" reaction may become more common than revolt. However, because our data do not extend to the nineteenth century, we cannot test this hypothesis. Our control variable measuring the existence of representative institutions produced mixed results. The Estates General tended to 905 suppress revolt in France as a whole, suggesting that it worked as a forum for negotiation and information exchange in early modem France, but it had no effect on revolts in Guyenne. Moreover, we found no effect for provincial estates-they did not affect revolts in Guyenne, and had virtually no effect in our rough analysis of France as a whole. The effects of taxation and offensive war on revolt are complicated, due primarily to the existence of a significant historical turning point in our period. As we anticipated, the relationship between taxation and revolt was very different before the Fronde than after it. Prior to the Fronde, tax increases tended to generate revolts; after the Fronde they rarely did. The effects of offensive war on revolt are similar, in that they too were strongly affected by the Fronde. Offensive wars generated revolts prior to the Fronde. As with tax increases, the Fronde proved to be a decisive turningpoint-indicated in this case by the fact that offensive wars following the Fronde had no effect on revolt. These findings clearly demonstrate that history matters. Particularhistorical turning points change the causal relationships between variables (Goldstone 1998; Issac and Griffin 1989; Mahoney 2000; Peirson 2000). In this case, the Fronde was a clear and decisive victory for the state over rebellious subjects. The combination of repression and co-optation that followed it significantly changed the costs and benefits of revolt for more than a century. After the Fronde, subjects less often thought of revolt as a potentially successful strategy for decreasing taxes or opposing offensive wars, and statemaking proceeded relatively unimpeded. Although our empirical analysis is limited to France, we believe many of our arguments could apply to other early modern states in the process of state formation. For example, other states could also have experienced turning points that transformed the relationship between state-making and revolt. Although further research would be necessary to test this, it is possible that the "GreatRevolt" of 1381 in England and the Comuneros revolt in Spain (1520-1521) may have played roles similar to the Fronde. Both were responses to state-making, increased taxation, and administrativecentralization(Elliott 1963:141- 906 AMERICAN SOCIOLOGICAL REVIEW 49; Fryde 1981:9-11; Hopcroft 1999:74-75; Thompson 1994:182-85). Fryde (1981) and Hopcroft (1999) argue that the English tax revolt remained in popular memory and shaped the fiscal evolution of the English state for centuries by defining the limits of taxation (specifically, an invasive tax like the poll tax would not be tolerated). The Comuneros revolt in Spain, like the Fronde, resulted in a decisive victory for the state (Elliott 1963: 149; Thompson 1994:184). After thatpoint, the Cortes was marginalized, administrative centralization and taxes increased, yet "there were no more revolts in Castile against the power of the crown" (Elliott 1963:149). These and other turning points may well be keys to increasing our understandingof early modern state formation and reactions against it. APPENDIX Edgar Kiser is Professor of Sociology at the University of Washington. He has published articles in sociology, political science, and economics journals on topics including the determinants of war and revolt, the development and decline of voting institutions, the centralization and bureaucratization of state administration, and the methodology of historical sociology. April Linton is currently a visiting research fellow at the Office of Population Research, Princeton University, and will be, effective July 2004, Assistant Professor of Sociology at the University of California, San Diego. Her dissertation, completed in July 2002 at the Department of Sociology, University of Washington, is titled "Spanish for Americans? The Politics of Bilingualism in the United States." Currently she is pursuing research about bilingualism and language policy, thefair trade movement, and revolutions that incite large-scale social transformations. A Tax Revolts in France, 1514 to 1789 Year Location Description 1514 Agen, Guyenne Taxation and political exclusion 1528 Bordeaux, Guyenne Excise tax on wine 1539 Marseille, Provence Gabelle 1542 La Rochelle and Les Iles, Saintonge Gabelle 1544 St. Maixent, Poitou Taxation, religion 1545 Perigeux, St Foy, and Duras, NW Guyenne Gabelle 1545 Sarlat, Niort, and Saintes, Poitou Taxation 1545 St. Maixent, Poitou Taxation 1548-1551 Guyenne Pitaud insurrection 1594-1595 Guyenne Croquantrebellions 1621-1622 Bearn First Bearnese Revolt 1625-1626 B6arn Second Bearnese Revolt 1627-1629 Bearn Third Bearnese Revolt 1629-1630 Guyenne Croquantuprising 1635-1636 Guyenne Croquantuprising 1635-1636 Languodoc Croquantuprising 1637-1641 Perigord and Quercy, Guyenne Croquantuprising 1639 Normandy Nu-pieds 1640 Moulins, Bourbonnais Taxation 1640 Rennes, Brittany Taxation 1641 Poitou Taxation 1641 Saintonge Taxation 1643-1644 Languodoc Rouerge revolt in the South and West 1645 Montpellier, Languodoc Taxation 1648-1653 Angers, Anjou The Fronde (Continued on next page) STATE-MAKING AND REVOLT IN EARLY MODERN FRANCE (AppendixA continued) Year Location 1650-1651 Bordeaux, Guyenne The Fronde 1650 Tulle, Limosin The Fronde 1652 Guyenne, Ormee of Bordeaux 1655-1657 Guyenne 1658 Orldanais Sabotiers rebellion 1661-1662 Guyenne Benauge rebellion 1662 Boulonnais (Artois) Lustucru rebellion 1663 Roussillon, Languodoc Angelets guerilla warfare 1663-1670 Gascony, Guyenne Audijos rebellion 1675 Brittany Papier Timbre, Bonnets Rouges (Torreben) rebellions 1789 French Revolution Description Tardanizatrebellion Sources: Heller (1991); Kiser et al. (1993); Tilly (1986, 1993). APPENDIX B Wars Involving the French, 1515 to 1788 Year War Type of Wara 1521-1526 First Italian War Defensive 1526-1530 Second Italian War Defensive 1535-1538 Third Italian War Offensive 1542-1544 Fourth Italian War Offensive 1544-1546 Anglo-French War Defensive 1547-1559 Hapsburg-Valois War Offensive 1549-1550 1557-1561 Anglo-French War Anglo-French War War of the Three Henries Defensive 1609-1614 1624-1648 War of the Julich Succession Offensive French Thirty Years War Offensive 1627-1628 Defensive 1628-1631 Anglo-French War War of the Mantuan Succession 1642-1696 Iroquois-French War 1648-1659 1667-1668 Offensive 1672-1689 Franco-Spanish War War of Devolution Third Dutch War 1676-1679 Messian Rebellion Offensive 1688-1697 1701-1714 War of the Grand Alliance Offensive Spanish Succession Offensive 1718-1720 1733-1738 1744-1748 Quadruple Alliance Polish Succession King George's War French and Italian War Seven Years War Corsican War American Revolution Defensive Offensive Defensive Offensive Defensive Offensive Offensive 1589-1598 1754-1763 1756-1763 1764-1769 1775-1783 a We define wars initiated by powers other than France as defensive wars. Sources: Dupuy and Dupuy (1977); Kiser et al. (1993, 1995). Defensive Offensive Defensive Defensive Offensive Offensive 907 908 AMERICAN SOCIOLOGICAL APPENDIX REVIEW C Pearson Correlation Coefficients for Variables Used in the Regression Analyses of Tax Revolt Initiation in France, 1515 to 1789 Variable Variable (1) (1) Revolt Initiation 1.000 (2) Total tax per capita -.129* (3) Before/during the Fronde .183** (4) Administrative centralization -.094 (5) Estates General -.073 (3) (2) (4) (5) (6) (7) (8) 1.000 -.776*** 1.000 .776*** -.923*** 1.000 .754*** -.816*** 1.000 -.705*** (6) War .185** .039 -.152** .211*** -.227*** 1.000 (7) Defensive war .068 .012 -.223*** .334*** -.279*** .516*** 1.000 (8) Offensive war .185** .077 -.055 .135* .741*** -.206*** .120* 1.000 Note: All independent variables are lagged one year. *** < .001 (two-tailed tests) ** <.01 *p <.05 REFERENCES Abbott, Andrew. 1997. "On the Concept of Turning Point." Comparative Social Research 16:85-105. 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Such other-regarding choice is another example in which individual behavior differs from that predicted by subgame perfection, and supports the call for a new "behavioral game dieory" (Colin F. Camerer, 1997). Herein we extend the work of HMS to reveal a setting in which 95 percent of dictators follow game-theoredc predictions. In contrast to previous studies, our design has people bargain over eamed wealth rather than uneamed wealth granted by the experimenter. We aigue that just as rewaids must be salient (Kyung Hwan Baik et al., 1999), the assets in a baigain must be legidmate to produce radonal behavior.' Our results support this conjecture. Dictators bargaining over eamed wealth were more selfinterested than observed in previous studies; * Cheny: Depaitment of Economics, Appalachian State Univeisity, Boone. NC 28608; Ftykblom: Department of Economics. Swedish Univenity of Agricultural Sciences. Uppsala, Sweden: Shogren: Department of Economics and Fmance. University of Wyoming. Laramie. WY 82071. This research benefited grndy fiom Cheny's visit to the Economic Science Laboiatoiy at dw Univeisity of Arizona. Financial suppoit was partially provided by STINT, the Univeisity of Central Florida, and dw Bugas Fund at dw University of Wyoming. Charles Holt, Stephan Kroll, John List, Nicholas Rupp, and an anonymous referee provided helpful comments. ' While diis proposidon has not been explicidy examined in bargaining behavior, diere is closely related work widiin dw economics and psychology literature: for example, found-money effiect and mental accoundng (e.g.. Milton Friedman, 1957; James P. Keeler et al.. 1985; Richard Thaler, 1990: Hal Arices et al.. 1994; James Konow. 2000). and when they had complete anonymity, selfless behavior is essendally eliminated. L Ex PreUminaries.—Subjects wererecruitedfrom die undeigraduale student body at die University of Central Florida. All subjects were unfamiliar with bargaining games. We conducted three sessions, each having 52 or 61 bargaining pairs. Participants were randomly assigned to two groups, split into rooms A and B. The two groups did not have any contact before, during, or after the session. Subjects were only allowed to talk to administrators. Stages.—The experiment had two stuges (eamings and bargaining), each with a written protocol to ensure consistency. The eamings stage had subjects in Room A participate in a money-eaming session without knowledge of die second bargaining stage. Subjects eamed money by taking a quiz containing 17 questions taken from the sample secdon of the Graduate Management Admission Test (GMAT).- The amount eamed was determined by the following mle: if the subject answered at least ten quesdons correcdy, he or she would eam $40; otherwise, he or she received $10. Subjects knew they had 45 minutes to complete the quiz. After the dme elapsed, the monitors collected and graded the quizzes, and distributed cash eamings to each subject in confidence according to the specified eamings mle. After receiving their money, the subjects who eamed $40 were put in a separate room (Room Al) from those who eamed $10 (Room A2). The bargaining stage randomly matched subjects in Room Al and A2 with diose in Room B to form baigaining pairs. The person in Room A was thefirstmover (i.e.. dictator) and bargained over his or her eamed wealth. Instmctions for -The instrucdons are available upon request and the earnings quiz is provided in John A. List and Cheny (2000). Pilot sessions indicate die effect of dw earnings session is robust acioss tasks other than a quiz. 1218 VOL 92 NO. 4 CHERRY ETAL: HARDNOSE THE DICTATOR the dictator game were read aloud to both groups.^ All bargaining games were one-shot, and players had complete information. For each pair, the player in Room Al or A2 dictated a split of his or her wealth with the person in Room B. Administrators carried the offers from Room Al and A2 to Room B. Final eamings were paid according to the dictated split, and subjects departed one at a time with their cash payment. This concluded the bargaining stage, and ended the session. 1219 The only adjustments we make to incorporate the eaming session with HMS's isolation design is to separate those that eamed $40 versus $10, and adjust the number of blank slips of paper in the envelopes; 40 slips and bills, or 10 slips and bills. n. Resuits and Condnsion Figures 1 and 2 provide the cumulative distributions from our low- and high-stakes experiments. Results indicate that other-regarding Treatments.—^Based on the two-stage design, behavior is greatly diminished when bargaining involves eamed wealth, and this behavior is we created three treatments: baseline, eamings, nearly eliminated when eamed stakes are comand double blind with eamings. Given the dichotbined with anonymity. omous outcome of earnings, each of the three In the baseline treatments, the theoretically treatments had a high- and low-stakes session. In predicted "zero offer" occurred in 19 percent of the baseline treatment (B), subjects did not particthe low-stakes bargains and 15 percent of the ipate in an eamings stage prior to the baigaining high-stakes bargains. In contrast, legitimizing stage. As in previous studies, dictates in Room A wealth with an eamings session prior to barwere provided their wealth by the experimenter. gaining dramatically reduced off-equilibrium Specifically, subjects were tokl that "$X has been provisionally allocated to each pair and the person behavior, with zero offers arising in 79 and 70 percent of the bargains in the low- and highin Room A can propose how much of this each stakes eamings treatments. As the diagrams person is to receive." Dictators were allocated illustrate. Fisher's exact and Wilcoxon tests reeither $40 or $10 to provide a clean comparison to veal that the proportions of nonzero offers and the two potential eamings outcomes. the distribution of offers in the eamings treatIn the eamings treatment (E), subjects in ments are significantly lower than those found Room A participated in the eamings stage prior in the baseline treatments (p < 0.0000 in all to the bargaining stage. Instructions informed cases).^ all subjects that "the person in Room A has eamed an amount of money by participating in Now consider the double-blind eamings treata previous session" and "the person in Room B ment. When isolated dictators acted over eamed has not had the opportunity to eam any money." wealth, self-interested game-theoretic behavior Further, they were informed "the person in was the norm. Bargainers made zero offers 95 Room A decides how much of his or her eamings they are to receive and how much of his or her eamings the person in Room B is to rethe administrator reads the instructions aloud; (c) each perceive." For time management, subjects in Room son in Room A individually and randomly selects one of N + 2 opaque envelopes, in which N envelopes contain 10 B arrived one hour after those in Room A. (or 40) one-dollar bills and 10 (or 40) slips of paper, and the The double blind with earnings (DBE) treattwo additional envelopes contain 20 (or 80) slips of blank ment was identical to the eamings treatment, paper: (d) subjects open the envelope behind a large cardexcept that the bargaining stage was identical to board box and decide how many bills to leave for tbe person in Room B, where slips of paper replace bills to ensure the Double Blind 1 (DBl) protocol in '* ^ As in HMS, we used the experimental instructions from Robert Forsythe et al. (1994) as the baseline with the adjustment to incorporate whether die wealth was eamed or allocated. We note that it was common knowledge whether the stakes were eamed or allocated but only dictators knew of the two stake levels ($10 vs. $40). * In the DB 1 experiment, (a) the administrator chooses a subject from Room A to oversee the bargaining stage: (b) consistency in envelope thickness; (e) subjects seal the envelope and drop it in a box as they exit; (f) the process is repeated for all people in Rooms Al and A2; (g) the administrator takes the box of envelopes outside of the door of Room B; (h) people in Room B individually exit, in which they randomly select an envelope and the contents arerecordedby the administrator; (i) this process is repeated for eveiyone in Room B; and (j) the experiment concludes with the payment of the overseer selected in step (a). ' The Wilcoxon test statistic was W = 4.S7 for high stakes and W = 4.32 for low stakes. 1220 THE AMERICAN ECONOMIC REVIEW 4 SEPTEMBER 20O2 5 6 Offer (USS) RGURE I. CUMULATIVE DISTRIBUTIONS OF OFFERS IN THE $10 DICTATOR GAME.S FIGURE 2. CIAIULATIVE DISTRIBUTIONS OF OFFERS IN TOE $40 DICTATOR GAME.S percent of the time in the double-blind eamings treatments and 97 percent of the time in the high-stakes treatment. Such hardnose behavior by dictators stands in stark ccmtrast to previous work that reports only 20-60 percent of observed behavior adhere to subgame perfection. The frequency of nonzero offers and the distribution of offers observed in the double-blind eamings sessions is significantly lower than those in the baseline (p < 0.0000). Comparing the double-blind eamings and the straight eamings treatments, tests indicate that the increased anonymity from the double-blind pmtacol significantly lowered the frequency and distribution of off-equilibrium behavior in the highstakes sessions (Fisher's exact, p < 0.007; IV = 3.14, p = 0.002). Tests were less con- vincing for the low-stakes sessions (Fisher's exact, p = 0.256 and W = 1.40, p = 0.16).* We conclude with two observations that have broader implications. First, legidmizing wealth with effort is no less important than controlling reciprocity in explaining other-regarding behavior in simple bargaining games. It follows that asset origin could affect the degree of anomalistic behavior witnessed in other experimental settings. WindfaU wealth, for instance, might explain the lack of free-riding in the provision of public goods in the lab(»atory. Second, asset " Note tiiat behavior was statistically equivalent across ^ and low stakes. Uw result of no wealtii efftcts witii eamed money conesponds to previous findings witii allocated wealtii (e.g., Foisytiw et al.. 1994). VOL 92 NO. 4 CHERRY ETAL: HARDNOSE THE DICTATOR origin combined with isolation closed a longstanding gap between standard game theoiy and observation. When assets are legitimized with effort and strategic concems are controlled with isolation, altmism was the exception and selfinterest was the mle. Strategic concems—not faimess—appear to be the motivation for otherregarding behavior when people baigain over eamed wealth. This raises the question of when the efforts to explain the gq> generated by windfall assets are necessaiy. REFERENCES Arkes, Hal R.; Joyner, CyntUa A.; Pfeso, Mark V.; Nash, Jane G.; Siegel-Jacohs, Kuen and Stone, Eric "The Psychology of Windfall Gains." Organizational Behavior and Human Decision Processes, September 1994, 59(3), pp. 331-47, Balk, Kyung Hwui; Cherry, Todd L.; Kroil, St^ian and Shogran, Jason F. "Endogenous Timing in a Gaming Toumament." Theory and Decision, August 1999,47(\), pp, 1-21. Canwrer, Colin F. "Progress in Bdiavioral Game Theoiy." Joumal of Economic Perspectives, Autunui 1997, 77(3), pp. 167-88. Foi^ythe, Rohert; Horowitz, Joel; Smin, N. E. and Sefton, Martin. "Faimess in Simple Bar- 1221 gaining Experiments." Games and Economic Behavior, May 1994, 6(3), pp. 347-69. Friedman, MiKon. A theory qfthe consumption function. Princeton, NJ: Princeton University Press, 1957. Hofhnan, EHzahcth; McCahe, Kevin and Smith, Vemon. "Social Distance and Other-Regarding Behavior in Dictator Games." American Economic Review, June 1996, 86(3), pp. 653-60. Keeler, James P.; James, WiiHam L. and AbdeiGhany, Mohamed. "The Relative Size of Windfall Income and the Permanent Income Hypothesis." Joumal qf Business and Economic Statistics, June 1985, 3(3), pp. 20915. Konow, James. "Fair Shares: Accountability and Cognitive Dissonance in Allocation Decisions." American Economic Review, September 2000, 90(4), pp. 1072-91. List, John A. and Cherry, Todd L. "Leaming to Accept in the Ultimatum Game: Evidence fiom an Experimental Design that Generates Low Offers." Experimental Economics, June 2000, J(l), pp. 11-29. Thaler, Richard. "Savings, Fungibility, and Mental Accounts." Joumal of Economic Perspectives, Winter 1990, 4(1), pp. 193205. In Search of Homo Economicus: Behavioral Experiments in 15 Small-Scale Societies By JOSEPH HENRICH, ROBERT BOYD, SAMUEL BOWLES, COLIN CAMERER, ERNST FEHR, HERBERT GINTIS, AND RICHARD MCELREATH* Recent investigations have uncovered large, consistent deviations from the predictions of the textbook representation of Homo economicus (Alvin E. Roth et al,, 1991; Ernst Fehr and Simon Gachter, 2000; Colin Camerer, 2001), One problem appears to lie in economists' canonical assumption that individuals are entirely self-interested: in addition to their own material payoffs, many experimental subjects appear to care about fairness and reciprocity, are willing to change the distribution of material outcomes at personal cost, and are willing to reward those who act in a cooperative manner while punishing those who do not even when these actions are costly to the individual. These deviations from what we will term the canonical model have important consequences for a wide range of economic phenomena, including the optimal design of institutions and contracts, the allocation of property rights, the conditions for successful collective action, the analysis of incomplete contracts, and the persistence of noncompetitive wage premia. Fundamental questions remain unanswered. Are the deviations from the canonical model evidence of universal patterns of behavior, or do the individual's economic and social environ* Henrich: School of Business Administration, University of Michigan, Ann Arbor, Ml 48109; Boyd and McElreath: Department of Anthropology, University of California at Los Angeles, Los Angeles, CA 90095; Bowles: Department of Economics, University of Massachusetts, Amherst, MA 01003, and Santa Fe Institute; Camerer: Department of Economics, California Institute of Technology, Pasadena, CA 91125; Fehr: Institute for Empirical Research in Economics, University of Zurich, Blumlisalpstrasse 10, CH-8006, Zurich, Switzerland; Gintis; University of Massachusetts, Amherst, MA 01003, The research described in this paper was funded by the MacArthur Foundation's Research Group on the Nature and Origin of Norms and Preferences, directed by Robert Boyd and Herbert Gintis. The field experiments were carried out by Henrich, MeElreath, Michael Alvard, Abigail Barr, Jean Ensminger, Francisco Gil-White, Michael Gurven, Kim Hill, Frank Marlowe, John Patton, Natalie Stnith, and David Tracer. ments shape behavior? If the latter, which economic and social conditions are involved? Is reciprocal behavior better explained statistically by individuals' attributes such as their sex, age, or relative wealth, or by the attributes of the group to which the individuals belong? Are there cultures that approximate the canonical account of self-regarding behavior? Existing research cannot answer such questions because virtually all subjects have been university students, and while there are cultural differences among student populations throughout the world, these differences are small compared to the range of all social and cultural environments. To address the above questions, we and our collaborators undertook a large cross-cultural study of behavior in ultimatum, public good, and dictator games. Twelve experienced field researchers, working in 12 countries on five continents, recruited subjects from 15 small-scale societies exhibiting a wide variety of economic and cultural conditions. Our sample consists of three foraging societies, six that practice slash-and-bum horticulture, four nomadic herding groups, and three sedentary, small-scale agriculturalist societies. Our results are described in detail, with extensive ethnographic accounts of the cultures we studied and citations to the relevant literature, in Henrich et al. (2001); an extended overview paper is available online.' We can summarize our results as follows. First, the canonical model is not supported in any society studied. Second, there is considerably more behavioral variability across groups than had been found in previous cross-cultural research, and the canonical model fails in a wider variety of ways than in previous experiments. Third, group-level differences in economic organization and the degree of market ' URL: {www.santafe.edu) 73 AEA PAPERS AND PROCEEDINGS 74 integration explain a substantial portion of the behavioral variation across societies: the higher the degree of market integration and the higher the payoffs to cooperation, the greater the level of cooperation in experimental games. Fourth, individual-level economic and demographic variables do not explain behavior either within or across groups. Fifth, behavior in the experiments is generally consistent with economic patterns of everyday life in these societies. I. The Evidence Because the ultimatum game (UG) has been conducted throughout the world with student populations and has generated robust violations of the canonical model, we conducted this game in all of our 17 societies. The "proposer" in this game is provisionally assigned an amount equivalent to a day or two's wages in the society and asked to propose an offer to a second person, the "respondent." The respondent may then either accept the offer, in which case the two players receive the proposed amounts, or reject it, in which case the two receive nothing. If both players conform to the canonical model and if this is common knowledge, it is easy to see that the proposer will know that the respondent will accept any positive offer and so will offer the smallest possible amount, which will be accepted. In most of our field experiments subjects played anonymously, not knowing the identity of the person or persons with whom they were paired. The stakes of most games were denominated in money (though in some cases tobacco or other goods were used). In all cases, we tested prospective participants for their comprehension of the experiment and eliminated any who appeared not to grasp the game. The systematic deviations from the canonical model in our sample of simple societies can be inferred from Table 1, which lists all groups where UG's were conducted. Contrary to the prediction of the standard model, even the groups with the smallest offers have mean offers greater than 25 percent of stake size. Illustrating our second result (the large variation in mean offers across societies), others, including the Torguud and the Mapuche, offered between 30 percent and 40 percent, while still others, including the Achuar and the Sangu, offered MAY 2001 TABLE 1—THE ULTIMATUM GAME IN SMALL-SCALE SOCIETIES Group Macbiguenga Country Peru Mean offer" 0.26 Tanzania Hadza (big camp) Tanzania Hadza (small camp) Tsiman6 Bolivia 0.40 Quichua Ecuador 0.27 Torguud Mongolia 0.35 Khazax Mapuche Mongolia Chile 0.36 0.34 Au PNG 0.43 Gnau PNG 0.38 0.27 (38) 0.37 Sangu farmers Sangu herders Unresettled villagers Resettled villagers Achuar Tanzania 0.41 Tanzania 0.42 Zimbabwe 0.41 Zimbabwe 0.45 Ecuador 0.42 Orma Kenya 0.44 Achi Paraguay 0.51 Lamelara^ Indonesia 0.58 Lowoffer rejection rate'' Modes'" Rejection rate' 0.15/0.25 (72) 0.50 (28) 0.20 (8/29) 0.048 (1/21) 0.19 (5/26) 0.28 (5/16) 0.10 (I/IO) 0.80 (4/5) 0.31 0.5/0.3/0.25 (65) 0.25 (47) 0.25 (30) 0.25 0.50/0.33 (46) 0.3 (33) 0.00 (0)70) 0.15 (2/13) 0.05 (1/20) 0.00 (0/5) 0.50 (i/2) 0.00 (0/1) 0.067 (2/30) 0.27 (8/30) 0.2 (2/10) 1.00 (1/1) 0.50 (3/6) 1.00 (1/1) 1.00 (1/1) 0.33 (2/5) 0.57 (4/7) 0.00 (0/1) 0.00 (0/0) 0.00 (0/8) 0.00 (4/20) 0.4 (32) 0.50 (35) 0.50 (40) 0.50 (56) 0.50 (70) 0.50 (36) 0.50 (54) 0.50/0.40 (75) 0.50 (63) 0.4 (10/25) 0.25 (5/20) 0.05 (1/20) 0.1 (3/31) 0.07 (12/86) 0.00 (0/16) 0.04 (2/56) 0.00 (0/51) 0.00 (3/8) Note: PNG = Papua New Guinea. ° This column sbows the mean offer (as a proportion) in the ultimatum game for each society. "•Tbis column shows the modal offer(s), with the percentage of subjects who make modal offers (in parentheses). " The rejection rate (as a proportion), with the actual numbers given in parentheses. '' Tbe rejection rate for offers of 20 percent or less, with the actual numbers given in parentheses. ' Includes experimenter-generated low offers. between 40 percent and 50 percent. Finally, the Ache and the Lamelara had mean offers greater than 50 percent. These group differences are strikingly large compared to previous cross-cultural work comparing ultimatum-game behavior among university students (Roth et al., 1991). While mean offers in industrial societies are typically close to 44 percent, the mean offers in our sample range from 26 percent to 58 percent. Similarly, while modal offers are consistently 50 percent VOL 91 NO. 2 ECONOMICS AND SOCIAL BEHAVIOR in industrialized societies, our sample modes vary from 15 percent to 50 percent. As shown in the last two columns of Table 1, rejections are also much more variable than previously observed. While in industrial societies offers below 20 percent are rejected with probability 0.40 to 0.60, rejections of low offers are extremely rare among some groups. In other groups, however, we observe substantial rejections rates, including frequent rejections of offers above 50 percent. Among the Achuar, Ach6 and Tsimane, we observe zero rejections after 16, 51, and 70 proposer offers, respectively. Moreover, while the Ach6 and Achuar made fairly equitable offers, nearly 50 percent of Tsiman6 offers were at or below 30 percent, yet all were accepted. Similarly, Machiguenga responders rejected only one offer, despite the fact that over 75 percent of their offers were below 30 percent. At the other end of the rejection scale, Hadza responders rejected 24 percent of all proposer offers and 43 percent of offers at 20 percent and below. Unlike the Hadza, who preferentially rejected low offers, the Au and Gnau of Papua New Guinea rejected both unfair and hyper-fair (greater than 50 percent) offers with nearly equal frequency. In experiments with university subjects, offers are generally consistent with incomemaximization, given the distribution of rejections. In our sample, however, in the majority of groups the modal behavior of the proposers is not consistent with expected incomemaximization. In the Tsimane and Ach6 cases, for instance, there are no rejections of offers below 20 percent, although there were several low offers. The rejection rate for all other offers is also zero. Yet the modal offer in both groups is 50 percent, and the average offers are 37 percent and 51 percent, respectively. Where possible, we used the relationship between the size of the offer and the fraction of rejections to estimate income-maximizing offers for the group in question. In one group, the Hadza proposers approximated the income-maximizing offer quite closely, thus confirming the canonical model; but Hadza responders frequently rejected substantial positive offers, thus violating the canonical model. In all other groups, average offers exceeded the income-maximizing offer, in most cases by a substantial amount. 75 Data from public-goods games played in seven of these societies also show much greater variation than previously found, and again they exhibit novel deviations from the predictions of the canonical model. Public-goods games ask subjects to contribute to a common pool that will be expanded by the experimenter and then redistributed to all subjects. The canonical prediction is that everyone will free-ride, contributing nothing. Typical distributions of publicgoods game contributions with students have a U-shape, with the mode at contributing nothing, a secondary mode at full cooperation, and mean contribution between 40 percent and 60 percent. By contrast, for instance, the Machiguenga have a mode at contributing nothing, with not a single subject cooperating fully, yielding a mean contribution of 22 percent. Also, the Achd and Tsiman6 both exhibit inverted distributions, with few or no contributions at full free-riding or full cooperation. In three dictator games played in three of these societies, groups also deviate both from typical behavior in industrialized societies and the canonical predictions. The dictator game allows the proposer simply to assign some fraction of the stake to a passive second party who receives that amount. Among university students, the distribution of "offers" in the dictator game typically has a mode at zero and a secondary mode at 50/50, while the canonical model predicts that people will give zero. Contrasting with both, the Orma have a mode at 50 percent and a secondary mode at 20 percent. Hadza dictators show a mode at 10 percent. Offers of 0 percent and 50 percent are also popular. Among the Tsiman6, there were no zero offers; the mean was 32 percent, and the mode was 25 percent, II. What Explains Group-Level Differences? The large variations across the different cultural groups suggest that preferences or expectations are affected by group-specific conditions, such as social institutions or cultural fairness norms. The large variance in institutions and norms in our sample allowed us to address this question systematically. Because of space limits we here concentrate on the behavior of proposers in the UG, We rank-ordered the societies along two dimensions: 76 MAY 2001 AEA PAPERS AND PROCEEDINGS (i) Payoffs to cooperation (PCj.—How important and how large is a group's payoff from cooperation in economic production? (ii) Market integration (MI).—How much do people rely on market exchange in their daily lives? On the first dimension, payoffs to cooperation, the Machiguenga and Tsimane rank the lowest; they are almost entirely economically independent at the family level and engage rarely in productive activities involving more than members of a family. By contrast, the Lamelara whale-hunters go to sea in large canoes manned by a dozen or more individuals. The rationale for PC as a predictor of UG offers is that with little cooperative production there will be little necessity to share returns, while those whose livelihood depends on large-scale cooperation like the Lamelara must develop ways of sharing the joint surplus. Thus we might expect that a higher level of PC will increase sharing behavior in the UG. The rationale for market integration as an explanatory variable is that the more frequently people experience market transactions, the more they will also experience abstract sharing principles concerning behaviors toward strangers of which the UG is an example. We sought to explain group mean UG offers on the basis of these two dimensions of economic structure. In a regression, both PC and MI were highly significant, their (positive) normalized regression coefficients were large in magnitude (about 0.3), and the two measures jointly explained 68 percent of the variance. The impact of PC and MI remains large and robust in an equation predicting individual offers, including individual measures such as sex, age, relative wealth, village population size, stake size, and experimenter experience with the group. Surprisingly, none of these individual level measures was significantly related to offers. A plausible interpretation of our subjects' behaviors is that, when faced with a novel situation (the experiment), they looked for analogues in their daily experience, asking "What familiar situation is this game like?" and then acted in a way appropriate for the analogous situation. For instance, the hyper-fair UG offers (greater than 50 percent) and the frequent rejections of these offers among the Au and Gnau reflect the culture of gift-giving found in these societies. Among these groups, like many in New Guinea, accepting gifts, even unsolicited ones, commits one to reciprocate at some future time to be determined by the giver. Receipt of large gifts also establishes one in a subordinate position. Consequently, excessively large gifts, especially unsolicited ones, will frequently be refused because of the anxiety about the unspecific strings attached. Similarly the low offers and high rejection rates of the Hadza appear to reflect their reluctant process of sharing (termed "tolerated theft" by a leading ethnographer of the Hadza). While the Hadza extensively share meat, many hunters look for opportunities to avoid sharing and share only because they fear the social consequences of not sharing, in the form of informal social sanctions, gossip, and ostracism. This behavior is apparently transferred to the experimental setting. Unlike the Hadza, the Ache did not reject low offers, and despite this the vast majority of the Ache (94 percent) made offers above 40 percent of the stake size. This coincides neatly with ethnographic descriptions indicating widespread meat-sharing and cooperation in community projects despite the absence of a fear of punishment in Ache society. Ache hunters, returning home, quietly leave their kill at the edge of camp, often claiming that the hunt was fruitless; their catch is later discovered and collected by others and then meticulously shared among all in the camp. We think it likely that the stake in the game seemed to some of the Ach^ subjects as analogous to their catch. The Machiguenga show the lowest cooperation rates in public-good games, reflecting ethnographic descriptions of Machiguenga life, which report little cooperation, exchange, or sharing beyond the family unit. By contrast, Orma experimental subjects quickly dubbed the public-goods experiment a haramhee game, referring to the widespread institution of villagelevel voluntary contributions for public-goods projects such as schools or roads. Not surprisingly, they contributed generously (58 percent of the stake), somewhat higher than most U.S. subjects contribute in similar experiments. III. Discussion Our data indicate that the degree of cooperation, sharing, and punishment exhibited by VOL 91 NO. 2 77 ECONOMICS AND SOCIAL BEHAVIOR experimental subjects closely corresponds to templates for these behaviors in the subjects' daily lives, and that the substantial variability in experimental behaviors across groups is an expression of the large between-group differences in the structures of social interaction and modes of livelihood. How do we interpret these results? Some of the variability among groups may be due to variations in implementation. We doubt that this explains the markedly differing behaviors across groups, however, since the experiments were run from identical protocols across groups and were thus as similar in procedures and stake size as we could achieve. Where we could test for experimenter effects we found none. It is possible also that our subjects presumed that their actions would somehow become public. In a good many of our cases, however, subsequent conversations with participants convinced us that this was not the case. Finally, it could be that participants thought they were in a repeated interaction, even though the games we used were clearly one-shot. We do not find this interpretation compelling, however, since there is extensive evidence from experiments in advanced economies that subjects understand the game very well, and those who reject a positive offer in the ultimatum game, when interviewed by the experimenter, typically do not say that they made an error, but rather affirm having goals besides maximizing a monetary payoff. Why are many subjects willing to share resources and undertake costly reciprocal actions in anonymous one-shot interactions? Bowles et al, (2001) will provide a more extensive response than can be offered here. We suspect that a proximate reason for these behaviors is that situations cue emotional responses which induce the behaviors we have measured. For example, many ultimatumgame responders from advanced societies, when facing a low offer, experience an emotional impulse to hurt the proposer for being unfair, just as the subject might in a real-life bargaining situation. Similarly, the New Guinea responders who rejected hyper-fair offers in the UG may have experienced the same anxiety that emerges when somebody gives them an unsolicited gift in everyday life. What are the ultimate determinants of our emotions and situation-specific cues? Here long-run evolutionary processes governing the distribution of genes and cultural practices could well have resulted in a substantial fraction of each population being predisposed in certain situations to forgo material payoffs in order to share with others, or to punish unfair actions, as our experimental subjects did, A number of recent contributions have shown that, under conditions that appear to approximate the social and physical environments of early human populations, prosocial behavior can proliferate in a population in which it is initially rare (Bowles et al,, 2001), IV. Conclusion While our results do not imply that economists should abandon the rational-actor framework, they do suggest two major revisions. First, the canonical model of the self-interested material payoff-maximizing actor is systematically violated. In all societies studied, UG offers are strictly positive and often substantially in excess of the expected income-maximizing offer, as are contributions in the public-goods game, while rejections of positive offers in some societies occur at a considerable rate. Second, preferences over economic choices are not exogenous as the canonical model would have it, but rather are shaped by the economic and social interactions of everyday life. This result implies that judgments in welfare economics that assume exogenous preferences are questionable, as are predictions of the effects of changing economic policies and institutions that fail to take account of behavioral change. Finally, the connection between experimental behavior and the structure of everyday economic life should provide an important clue in revising the canonical model of individual choice behavior, REFERENCES Bowles, Samuel; Boyd, Richard; Fehr, Ernst and Gintis, Herbert, eds. The foundations of social reciprocity. Unpublished manuscript. University of Massachusetts, 2001. Camerer, Colin F. Behavioral economics. Princeton, NJ: Princeton University Press, 2001 (forthcoming). 78 AEA PAPERS AND PROCEEDINGS Fehr, Ernst and Gachter, Simon. "Fairness and Retaliation: The Economics of Reciprocity." Journal of Economic Perspectives., Summer 2000, 74(3), pp. 159-81. Henrich, Joseph; Boyd, Robert; Bowles, Samuel; Camerer, Colin; Fehr, Ernst; Gintis, Herhert and McElreath, Richard. "Cooperation, Reciprocity and Punishment in Fifteen Small- MAY 2001 Scale Societies." Working paper, Santa Fe Institute, 2001. Roth, Alvin E.; Prasnikar, Vesna; Okuno- Fujiwara, Masahiro and Zamir, Shmuel. "Bargaining and Market Behavior in Jerusalem, Ljubljana, Pittsburgh, and Tokyo: An Experimental Study." American Economic Review, December 1991, 57(5), pp. 1068-95. Chimpanzees Are Rational Maximizers in an Ultimatum Game Keith Jensen, et al. Science 318, 107 (2007); DOI: 10.1126/science.1145850 This copy is for your personal, non-commercial use only. If you wish to distribute this article to others, you can order high-quality copies for your colleagues, clients, or customers by clicking here. Permission to republish or repurpose articles or portions of articles can be obtained by following the guidelines here. Updated information and services, including high-resolution figures, can be found in the online version of this article at: http://www.sciencemag.org/cgi/content/full/318/5847/107 Supporting Online Material can be found at: http://www.sciencemag.org/cgi/content/full/318/5847/107/DC1 A list of selected additional articles on the Science Web sites related to this article can be found at: http://www.sciencemag.org/cgi/content/full/318/5847/107#related-content This article cites 31 articles, 5 of which can be accessed for free: http://www.sciencemag.org/cgi/content/full/318/5847/107#otherarticles This article has been cited by 33 article(s) on the ISI Web of Science. This article has been cited by 7 articles hosted by HighWire Press; see: http://www.sciencemag.org/cgi/content/full/318/5847/107#otherarticles This article appears in the following subject collections: Psychology http://www.sciencemag.org/cgi/collection/psychology Science (print ISSN 0036-8075; online ISSN 1095-9203) is published weekly, except the last week in December, by the American Association for the Advancement of Science, 1200 New York Avenue NW, Washington, DC 20005. Copyright 2007 by the American Association for the Advancement of Science; all rights reserved. The title Science is a registered trademark of AAAS. Downloaded from www.sciencemag.org on August 12, 2010 The following resources related to this article are available online at www.sciencemag.org (this information is current as of August 12, 2010 ): REPORTS Keith Jensen,* Josep Call, Michael Tomasello Traditional models of economic decision-making assume that people are self-interested rational maximizers. Empirical research has demonstrated, however, that people will take into account the interests of others and are sensitive to norms of cooperation and fairness. In one of the most robust tests of this finding, the ultimatum game, individuals will reject a proposed division of a monetary windfall, at a cost to themselves, if they perceive it as unfair. Here we show that in an ultimatum game, humans’ closest living relatives, chimpanzees (Pan troglodytes), are rational maximizers and are not sensitive to fairness. These results support the hypothesis that otherregarding preferences and aversion to inequitable outcomes, which play key roles in human social organization, distinguish us from our closest living relatives. umans are able to live in very large groups and to cooperate with unrelated individuals whom they expect never to encounter again, conditions that make the standard mechanisms for cooperation unlikely (1), namely kin selection (2) and reciprocal altruism (3). Nevertheless, people help others, sometimes at great personal cost. But people are not obligate altruists; they do not tolerate abuse of their generosity. Not only will they punish or shun individuals who free-ride or exploit them, they will do so even if they themselves do not benefit from correcting the behavior of norm violators (4). The willingness both to cooperate and to punish noncooperators has been termed strong reciprocity (5) and has been claimed to be uniquely human (6). To cooperate in these ways, humans must be more than self-regarding rational decision-makers; they must also, at least to H Max Planck Institute for Evolutionary Anthropology, Deutscher Platz 6, D-04103, Leipzig, Germany. *To whom correspondence should be addressed. E-mail: [email protected] A some degree, have concern for outcomes and behaviors affecting others (other-regarding preferences) (4) as well as a general concern for norms of fairness (7, 8). The benchmark test for examining sensitivity to fairness and other-regarding preferences is the ultimatum game (9). In the standard version of the game, two anonymous individuals are assigned the roles of proposer and responder. The proposer is offered a sum of money and can decide whether to divide this windfall with the responder. The crucial feature of the ultimatum game is that the responder can accept or reject the proposer’s offer. If the responder accepts it, both players receive the proposed division; if the responder rejects it, both get nothing. The canonical economic model of pure self-interest predicts that the proposer will offer the smallest share possible and that the responder will accept any nonzero offer. This is not what happens. Although the specifics vary across culture and setting, the basic finding is that proposers typically make offers of 40 to 50% and responders routinely reject offers under 20% (10). These findings suggest that responders are B food dish Downloaded from www.sciencemag.org on August 12, 2010 sensitive to unfairness and punish proposers who make inequitable offers by rejecting those offers at a cost to themselves, and knowing this, proposers make strategic offers that are less likely to be refused. The ultimatum game has been used in dozens, possibly hundreds of studies, including various human cultures (11) and children (12). Testing the ultimatum game on other species would be an important contribution to the debate on the evolution and possible uniqueness of human cooperation (6). Chimpanzees are our closest extant relatives and engage in cooperative behavior such as group hunting, coalitionary aggression, and territorial patrols (13). Furthermore, in experiments they have been shown to coordinate their behavior (14) and to provide help (15, 16). However, there is ongoing debate about whether chimpanzees are sensitive to, and tolerant of, unfairness (17) or whether they simply attend to their own expectations with no regard for what others receive (18). Additionally, experiments have failed to reveal other-regarding preferences when food was involved (19, 20) other than to punish direct theft (21). Having chimpanzees play the ultimatum game would address these conflicting findings on fairness and negative reciprocity and allow direct comparisons to humans. In the current study, we tested chimpanzees in a mini-ultimatum game. The mini-ultimatum game is a reduced form of the ultimatum game in which proposers are given a choice between making one of two pre-set offers which the responder can then accept or reject (22). In one such study (23), there were four different games. In all games, the proposer had as one option an amount that would typically be rejected by a human responder as unfair, namely 80% for the proposer and 20% for the responder (8/2 offer; the proposer received the amount to the left of the slash and the responder received the amount to the right). In the 5/5 (fair) game, the proposer Chimpanzees Are Rational Maximizers in an Ultimatum Game C divider tray rope ends Proposer rods Responder Fig. 1. Illustration of the testing environment. The proposer, who makes the first choice, sits to the responder’s left. The apparatus, which has two sliding trays connected by a single rope, is outside of the cages. (A) By first sliding a Plexiglas panel (not shown) to access one rope end and by then pulling it, www.sciencemag.org SCIENCE the proposer draws one of the baited trays halfway toward the two subjects. (B) The responder can then pull the attached rod, now within reach, to bring the proposed food tray to the cage mesh so that (C) both subjects can eat from their respective food dishes (clearly separated by a translucent divider). VOL 318 5 OCTOBER 2007 107 was faced with the choice of 8/2 versus 5/5. The other games were 8/2 versus 2/8 (unfair versus hyperfair), 8/2 versus 8/2 (no choice), and 8/2 versus 10/0 (unfair versus hyperunfair). Human responders rejected the 8/2 offer most when the alternative was fair (5/5 game), less when the alternative was hyperfair (2/8 game), even less when there was no alternative (8/2 game), and hardly at all when the alternative was for the proposer to be even more selfish (10/0 game) (23). The differential rejection of unfair outcomes across the games suggests that people are not sensitive solely to unfair distributions (7) nor solely to unfair intent (24) but to a combination of both (8). If chimpanzees are sensitive to unfairness and are negatively reciprocal, they would behave like Homo reciprocans (25), whereas if they accept any nonzero offer regardless of alternatives for the proposer, they will be more like the hypothetical Homo economicus (26). Subjects were 11 chimpanzees from a grouphoused colony at the Wolfgang Köhler Primate Research Center (27). The proposer sat to the left of the responder, who was in an adjacent cage in an L-shaped arrangement. The test apparatus, which was outside of the cages, had two sliding trays. On each tray were two dishes with raisins, separated by translucent dividers: one for the proposer and the other for the responder (Fig. 1). Proposers would first choose one of the two trays by pulling it halfway to the cages (as far as it would go); responders could accept the offer by pulling the proposed tray the remaining distance (via the rod which came into reach only as a result of the proposer’s pull) or could reject it by not pulling at all within 1 min. The responder’s acceptance led to both subjects being able to reach the food in their respective dishes. Rejection led to both getting nothing, because the experimenter would remove all food dishes after the trial ended. There were four games (as in the study described above), all played within a single session: 2/8, 5/5, 8/2, and 10/0—each versus 8/2. The order of games was counterbalanced across subjects. The most important finding is that responders tended to accept any offer. As can be seen in Fig. 2, responders rejected 8/2 offers at overall Proposer Payoffs Responder Fig. 2. Offers made by Offers Proposer Responder Rejections proposers and rejections Game by responders in the four 8 2 games. In each game, the 39 (75%) 2 (5%) proposer could choose 5/5 between two payoff op5 5 13 (25%) 0 (0%) tions: 8/2 (8 raisins for the proposer and 2 for the responder) and an alternate [2/8 (2 for the 8 2 45 (87%) 3 (7%) proposer and 8 for the 2/8 responder), 5/5 (5 for 2 8 7 (13%) 0 (0%) the proposer and 5 for the responder), 8/2 (8 for the proposer and 2 8 2 for the responder), and 10/0 (10 for the proposer 53 (100%) 6 (11%) 8/2 8 2 and 0 for the responder)]. Results on the left show the total number and corresponding per8 2 centage of offers for each 29 (54%) 4 (14%) option made by propos10/0 10 0 ers in each game. (Trials 25 (46%) 11 (44%) in which the proposer did not participate are not included, therefore the total number of offers varies across the games; percentages are therefore based on the total number of offers for each option out of the total number of trials played for each game.) Results on the right indicate the total number of each offer rejected and the corresponding percentage of rejections out of the total number of offers for each game. 50 Rejection Rate (%) Fig. 3. Rejection rates (% of trials) of 8/2 offers in the four games for chimpanzees in this study (black bars) and for human participants (white bars) [data are from (23)]. 40 30 20 10 0 5/5 2/8 8/2 Game 108 5 OCTOBER 2007 VOL 318 SCIENCE 10/0 low rates (from 5 to 14% of the time). There was a trend toward different rejection rates of 8/2 offers across the four games (Friedman’s c23 test = 6.643, P = 0.069). However, all paired comparisons were nonsignificant, indicating that, crucially, chimpanzees rejected 8/2 offers equally often regardless of the alternatives available to the proposers (27). Moreover, this trend toward rejections was in the opposite direction of the finding for humans (23). When proposers offered non-8/2 alternatives (available in all but the 8/2 game), responders accepted them differentially across the games (Friedman’s c22 test = 10.00, P = 0.012). In line with the principle of selfinterest to accept any nonzero offer, responders rejected 10/0 offers (in which the responder receives nothing) more often than 5/5 offers [Wilcoxon T+ test = 28.00, n = 8 (1 tie), P = 0.016] and marginally more often than 2/8 offers [Wilcoxon T+ test = 15.00, n = 7 (2 ties), P = 0.063]. Indeed, the only offers rejected by responders more than 0% of the time were 10/0 offers (one-sample t test t9 = 4.735, P = 0.001). In short, responders did not reject unfair offers when the proposer had the option of making a fair offer; they accepted almost all nonzero offers; and they reliably rejected only offers of zero. As can be seen in Fig. 3, these results contrast strongly with those of adult humans, who reject 8/2 offers most often when a fair (5/5) option is available for the proposer and least often when the alternative for the responder is even more selfish than the 8/2 option (10/0) (23). Furthermore, unlike human responders, who report being angry when confronted with unfair offers (28), chimpanzee responders showed signs of arousal [displays and tantrums (13, 29)] in less than 2% of the test trials (all occurrences were by one individual in all trials of a single session), whereas in a previous study in which the subjects had food taken away from them, these same individuals exhibited tantrums or displays 40% of the time (21). Consistent with previous studies on chimpanzees (19, 20), proposers did not appear to take outcomes affecting the responder into account. When given the opportunity, proposers did not make fair offers (Fig. 2) [see also (27), and fig. S1]. Given the propensity of responders to accept any nonzero offer, it is not surprising that chimpanzee proposers acted according to traditional economic models of self-interest. However, it is perhaps surprising that proposers made zero offers to the responders, given that these offers were rejected at the highest rate (Fig. 2); chimpanzees are certainly capable of distinguishing two pieces of food from zero when choosing for themselves (30). To rule out more trivial interpretations of our results, it was necessary to demonstrate that responders and proposers understood the critical features of the task. To this end, we conducted familiarization and probe trials as well as a follow-up study. First, sensitivity to fairness in the ultimatum game requires that responders and proposers each know what the other gains. We www.sciencemag.org Downloaded from www.sciencemag.org on August 12, 2010 REPORTS REPORTS We gave chimpanzees the most widely recognized test for a sensitivity to fairness, the ultimatum game, and found that they did not systematically make fair offers to conspecifics, nor did they systematically refuse to accept unfair offers from conspecifics even though they could discriminate between the quantities available to themselves and their partners. It thus would seem that in this context, one of humans’ closest living relatives behaves according to traditional economic models of self-interest, unlike humans, and that this species does not share the human sensitivity to fairness. References and Notes 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14. 15. 16. 17. R. Boyd, P. J. Richerson, J. Theor. Biol. 132, 337 (1988). W. D. Hamilton, J. Theor. Biol. 7, 1 (1964). R. 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London Ser. B 272, 253 (2005). Widespread Role for the Flowering-Time Regulators FCA and FPA in RNA-Mediated Chromatin Silencing Isabel Bäurle,1* Lisa Smith,2† David C. Baulcombe,2‡ Caroline Dean1* The RRM-domain proteins FCA and FPA have previously been characterized as flowering-time regulators in Arabidopsis. We show that they are required for RNA-mediated chromatin silencing of a range of loci in the genome. At some target loci, FCA and FPA promote asymmetric DNA methylation, whereas at others they function in parallel to DNA methylation. Female gametophytic development and early embryonic development are particularly susceptible to malfunctions in FCA and FPA. We propose that FCA and FPA regulate chromatin silencing of single and low-copy genes and interact in a locus-dependent manner with the canonical small interfering RNA–directed DNA methylation pathway to regulate common targets. eterochromatin in many organisms is characterized by extensive DNA methylation and histone modifications (1). Plants display cytosine methylation in CG, CNG (N = any nucleotide), and CHH (H = A, H C, or T) sequence contexts. In Arabidopsis, small interfering RNAs (siRNAs) are involved in localizing and maintaining these chromatin modifications in processes requiring RNADEPENDENT RNA POLYMERASE2 (RDR2), www.sciencemag.org SCIENCE VOL 318 18. J. Bräuer, J. Call, M. Tomasello, Proc. R. Soc. London Ser. B 273, 3123 (2006). 19. J. B. Silk et al., Nature 437, 1357 (2005). 20. K. Jensen, B. Hare, J. Call, M. Tomasello, Proc. R. Soc. London Ser. B 273, 1013 (2006). 21. K. Jensen, J. Call, M. Tomasello, Proc. Natl. Acad. Sci. U.S.A. 104, 13046 (2007). 22. G. E. Bolton, R. Zwick, Games Econ. Behav. 10, 95 (1995). 23. A. Falk, E. Fehr, U. Fischbacher, Econ. Inq. 41, 20 (2003). 24. M. Rabin, Am. Econ. Rev. 83, 1281 (1993). 25. E. Fehr, S. Gächter, Eur. Econ. Rev. 42, 845 (1998). 26. R. H. Frank, Am. Econ. Rev. 77, 593 (1987). 27. Additional details on the methods and results can be found in the supporting material on Science Online. 28. M. Pillutla, J. Murnighan, Organ. Behav. Hum. Decision Processes 68, 208 (1996). 29. T. Nishida, T. Kano, J. Goodall, W. C. McGrew, M. Nakamura, Anthropol. Sci. 107, 141 (1999). 30. S. T. Boysen, G. G. Berntson, J. Comp. Psych. 103, 23 (1989). 31. However, the same subjects could discriminate 10 from 8 in a previous study (35), and chimpanzees can reliably discriminate 0 from 2 (30), which they would have done had they attended to responder outcomes. 32. M. Shinada, T. Yamagishi, Y. Ohmura, Evol. Hum. Behav. 25, 379 (2004). 33. K. J. Haley, D. M. T. Fessler, Evol. Hum. Behav. 26, 245 (2005). 34. J. Stevens, D. Stephens, Behav. Ecol. 13, 393 (2002). 35. D. Hanus, J. Call, J. Comp. Psych. 121, 241 (2007). 36. We thank the keepers of the Leipzig zoo, notably S. Leideritz, D. Geissler, N. Schenk, and “Mozart” Herrmann for their help; G. Sandler for reliability coding; R. Mundry for statistical advice; and two anonymous reviewers for helpful comments. Downloaded from www.sciencemag.org on August 12, 2010 therefore ran follow-up probe trials to determine whether the chimpanzees were capable of attending to the amount of food available to the partner. Subjects were tested alone, and they had to look into the distal food dishes to correctly choose the tray that would yield the largest payoff from the partner’s position before going through the open door to the adjacent cage to get it. They chose correctly at greater than chance levels, demonstrating that they would have been capable of seeing payoffs to the partner (27). Second, in inhibition probe trials, we found that subjects could inhibit pulling the rod when it led to no food gain about 64% of the time, about the same rate of pulling as in the 10/0 condition, suggesting that some of the failure to reject zero offers was due, at least some of the time, to an inability to inhibit a natural tendency to pull. Third, in discrimination probe trials, responders could distinguish between all offers available to them (fig. S2), and proposers could do so for all but 10/0 versus 8/2 (fig. S1) (31), demonstrating that subjects were able to make maximizing choices. Our subjects were from a single social group, they did not interact anonymously, and they played both roles in the game. However, anonymous one-shot games are used in experiments with humans to decrease the likelihood of making fair offers or accepting unfair offers (32, 33), and so if anything, our experimental design should have been skewed in favor of finding fairness sensitivity. The fact that chimpanzees in this study did not punish other individuals for making unfair offers may be in part a reflection of the fact that active food sharing is rare in this species (34) and may also be because they were unwilling to pay a cost to punish. Supporting Online Material www.sciencemag.org/cgi/content/full/318/5847/107/DC1 Materials and Methods SOM Text Figs. S1 and S2 References Movies S1 and S2 30 May 2007; accepted 16 August 2007 10.1126/science.1145850 DICER-LIKE3 (DCL3), ARGONAUTE4 (AGO4), and the two RNA polymerase IV isoforms, Pol IVa and b (2–9). To identify further components required for siRNA-mediated chromatin silencing, we used a reporter system in which the Arabidopsis phytoene desaturase (PDS) gene is silenced in response to a homologous inverted repeat (SUCPDS) (10). Two mutants that partially suppressed the silencing of PDS (Fig. 1, A, B, C, and E) showed late flowering that was reversible by vernalization. The silencing and flowering phenotypes cosegregated, and the mutations mapped to chromosomes 2 and 4. The flowering phenotype suggested involvement of FPA and FCA, two members of the autonomous pathway (11), mapping to those genomic regions. Sequencing revealed a premature termination codon in FPA (Trp98*, G to A, fpa-8) and FCA (Gln537*, C to T, fca-11). The flowering defect was confirmed by complementation analysis with previously known flowering mutants (fca-9, fpa-7, and fve-3; Fig. 1F), which also showed PDS silencing (fig. S1). Thus, FCA and FPA are required 5 OCTOBER 2007 109 Institute for Empirical Research in Economics University of Zurich Working Paper Series ISSN 1424-0459 Working Paper No. 318 Discrimination and In-group Favoritism in a Citywide Trust Experiment Armin Falk and Christian Zehnder April 2007 Discrimination and In-group Favoritism in a Citywide Trust Experiment∗ Armin Falk and Christian Zehnder† April 2007 Abstract This paper provides field experimental evidence on the prevalence and determinants of discrimination and in-group favoritism in trust decisions. We observe choices of about 1,000 inhabitants of the city of Zurich who take part in a sequential trust game, in which first movers can condition their investments on the residential districts of second movers. Our main results can be summarized as follows: First movers discriminate significantly in their investment choices, i.e., strangers receive different investments depending on the district they live in. The systematics of the discrimination pattern is underlined by data from an additional newspaper study, where participants correctly guessed the outcome of the study. In terms of district characteristics two factors seem to be key for a district’s reputation: while expected trustworthiness of a district increases in the socio-economic status it decreases in the degree of ethnic heterogeneity. Observed discrimination is not just based on mistaken stereotypes but can at least partly be classified as statistical discrimination. This can be inferred from the fact that, on a district level, both expected return on investment and actual investments are positively correlated with actual back transfers. First movers correctly anticipate different levels of trustworthiness and discriminate accordingly. Furthermore, we provide evidence of in-group favoritism, i.e., people trust strangers from their own district significantly more than strangers from other districts. Finally, we discuss individual determinants of discrimination and in-group favoritism. JEL-Classifications: C90, D63 Keywords: Discrimination, In-group Favoritism, Trust, Trustworthiness, Reciprocity, Social Capital, City Development ∗ Financial support by the Research Committee and the Young Academics Support Committee of the University of Zurich is gratefully acknowledged. We thank the Statistical Office of Zurich for very valuable support. We also like to thank seminar participants at Caltech, ENABLE Workshop (Fraueninsel), Mac Arthur Research Network Workshop (Philadelphia), University of Southern California, University of Chicago and University of Munich. † Armin Falk: IZA and University of Bonn, Schaumburg-Lippe-Strasse 7/9, D-53113 Bonn, [email protected]; Christian Zehnder: Institute for Empirical Research in Economics, University of Zurich, Bluemlisalpstrasse 10, CH-8006 Zurich, [email protected]. 1 Introduction Trust is an elementary component of social and economic life. It is therefore not surprising that economists have accumulated a large body of evidence on the existence and economic consequences of trust using field data, experiments and surveys. Surprisingly little is known, however, about whether people discriminate in their trust and if so, what determines whether they trust strangers from a particular group more than members from another group. We also know little about whether trust discrimination is based on stereotypes or actual differences in trustworthiness and what determines trust discrimination at the individual level. We address these questions with the help of a field experiment conducted among roughly 1,000 inhabitants of the city of Zurich. The experimental game is a variant of the so-called trust or investment game.1 In this sequential two-player game first movers send money to second movers, which is tripled by the experimenters. Second movers then decide how much to return. The amounts sent and returned inform us about the levels of trust and trustworthiness, respectively. Studying trust discrimination requires a social environment that defines distinct groups. In our study these groups are defined by the 12 districts of the city of Zurich. We think that districts of a city are a well-suited environment to study trust discrimination: districts are natural geographic entities, have a social meaning and are sufficiently heterogenous to potentially justify different reputations with respect to trust and trustworthiness. Moreover, district affiliation is relevant in every day transactions, which means that investments observed in the experiment can be interpreted as a proxy for efficiency enhancing and trust-related decisions taken every day, such as car repair or hiring and moving decisions. First movers in the experiment made a contingent decision: before knowing the residential district of their second mover they had to decide on an investment decision for each of the 12 districts, including their own district. This design feature allows us to study discrimination in a straightforward way, simply by comparing the amounts sent into the different districts. First movers were also asked about expected back transfers for each investment. Second mover decisions were elicited with the help of the contingent respond method, which enables us to measure actual trustworthiness of the inhabitants of different districts. Our data on the choices of first and second movers are complemented by socioeconomic and individual background information about all participants. The data come from two sources, the statistical office of Zurich and a questionnaire that each participant in the 1 This game was introduced by Berg et al. (1995). 1 experiment had to complete. We also use statistical information about the districts and data from an additional newspaper experiment we conducted in collaboration with a large daily newspaper in the Zurich area. In this experiment we asked newspaper readers from Zurich, who were informed about the rules of the experiment, to predict the outcome of the study. In particular they had to indicate the two districts that they thought would receive the lowest investments and the two districts that would receive the highest investments. To guarantee incentive compatibility we paid three randomly chosen readers among those whose answers were correct a prize of CHF 200. The results of our newspaper study provide a robustness check for our main experiment. If the newspaper readers predict the participants’ choices correctly, we have additional evidence that the discrimination pattern in our experiment is systematic. Our main findings can be summarized as follows. First, we investigate the prevalence of trust discrimination. We find that investment levels differ systematically across the residential districts of second movers, i.e., many first movers discriminate. Across districts first movers expect very different returns on investment and invest accordingly. The systematics of the discrimination pattern is supported by the results of our newspaper study. The readers predict which districts receive the highest and lowest investments extremely well. This underlines that beliefs about the districts’ different reputations are commonly shared. In terms of district characteristics that determine a trustworthy reputation, two factors are key: socioeconomic status and ethnic heterogeneity. The higher the economic status and the lower the ethnic heterogeneity, the higher is the reputation of a particular district, i.e., the higher is the expectation that a stranger from this district is actually trustworthy. Second, we explore the nature of the discrimination process. It turns out that observed discrimination is at least in part statistical in nature. This can be inferred from the fact that – on a district level – both expected return on investment as well as investments are positively and significantly correlated with actual trustworthiness. In other words, first movers correctly anticipate different levels of trustworthiness and discriminate on the basis of this belief. In a third step, we explore in-group favoritism, which is a particular form of discrimination, where people tend to favor members of their own group. We show that first movers invest significantly higher amounts to strangers who belong to their own district, compared to strangers from other districts. This in-group bias is not just taste driven as our data on expected back transfers reveals: first movers not only send more money, they also believe that fellow citizens from their own district are more trustworthy than strangers from other districts. 2 In a final step of the analysis we turn to the individual determinants of discrimination. We classify people who invest different amounts into different districts as discriminators and show that better educated people as well as people who have children discriminate less, while older people as well as people who favor right wing parties discriminate more. Turning to individual determinants of in-group favoritism we find that in-group favoritism is not significantly correlated with individual characteristics, such as gender or age. The only variable that significantly explains different levels of in-group favoritism is the degree to which people feel closely associated with their own district. Our paper offers several contributions to the literature. First, to the best of our knowledge, it is the first to document trust discrimination based on residential districts, i.e., on a community level.2 This type of discrimination is particular important in light of the fact that trust and trustworthiness constitute central components of a community’s social capital (see, e.g., the definitions in Loury, 1977; Coleman, 1990; Putnam, 2000), which influences a wide range of important economic phenomena, such as governmental and judicial efficiency (Putnam et al., 1993; La Porta et al., 1997), financial development and volume of trade (Guiso et al., 2004) or the rate of overall economic growth (Knack and Keefer, 1997; Knack and Zak, 2001). In this sense trust can be seen as a sort of lubricant for economic transactions, especially if markets are imperfect and contracts remain incomplete.3 Second, our results show that trust discrimination can be the result of statistical discrimination: first movers have relatively accurate expectations about districts’ trustworthiness and invest more in districts that are actually more trustworthy. This is different to previous studies where discrimination has not been statistical in nature. Fershtman and Gneezy (2001), e.g., investigated gender and race effects in a trust game played between Ashkenazic and Eastern Jews from two Universities in Israel. While there is no evidence for ethnic discrimination to and by women, male subjects exhibit a significant discrimination pattern, transferring less money to Eastern males than to Ashkenazic males. Different to our findings, however, this discrimination is not statistical but turns out to be the consequence of largely mistaken stereotypes. Third, our findings shed new light on the controversial issue of in-group favoritism. Starting with the famous “Robber’s Cave Experiment” by Sherif et al. (1961) many experiments in psychology have demonstrated the presence of in-group favoritism even if 2 Previous studies on discrimination have predominantly focused on ethnic or gender discrimination, starting with the seminal paper by Fershtman and Gneezy (2001), who investigated gender and race effects in a trust game played between Ashkenazic and Eastern Jews from two Universities in Israel. 3 In a famous quote Kenneth Arrow notes: “Virtually every commercial transaction has within itself an element of trust...”, see Arrow (1972), p. 357. 3 group affiliations are created artificially (see Yamagishi et al., 1999, for a survey of this literature). In recent years many economists have become interested in the phenomenon of in-group favoritism in trust decisions. Interestingly, the present state of the literature is fairly mixed. In experiments conducted on the basis of the minimal group paradigm the evidence in favor of an in-group bias is very weak (see e.g., Buchan et al., forthcoming; Güth et al., 2005). But also studies based on naturally defined groups provide ambiguous evidence. While a number of studies find no or only weak evidence for ingroup favoritism (see, e.g., Fershtman and Gneezy, 2001; Glaeser et al., 2000; Bouckaert and Dhaene, 2004; Haile et al., 2006), there are two studies which report a significant in-group bias in trust decisions (see, Bernhard et al., 2006; Götte et al., 2006). We contribute to the emerging literature on in-group favoritism in several ways. First, we show that in the context of city districts in-group favoritism is relevant in naturally occurring groups. Subjects in our study use their experience from every day life to determine how much they trust inhabitants from different parts of the city they live in. Second, we do not only document the existence of in-group favoritism but we are also able to explain at least part of it with subjects’ beliefs. Investments to the own district are not only higher because of taste but also reflect the fact that people expect higher returns on investments in their own district. Finally, we contribute to the existing literature by studying individual determinants that are driving trust discrimination and in-group favoritism. Our large and heterogenous non-student subject pool allows us to do this in a meaningful way. The remainder of the paper is organized as follows: in the next section we describe the design and the used background information. In section 3 we present our results. Section 4 summarizes and concludes the paper. 2 Design and Background Information In this section we first describe the details of the trust experiment and the questionnaire subjects had to complete. We then discuss the design of the complementary newspaper study. Finally, we describe data provided by the statistical office of Zurich. 2.1 A Field Experiment on Trust and Discrimination Our experimental tool to measure trust and trustworthiness is a variant of the so-called trust or investment game introduced by Berg et al. (1995). Two randomly chosen subjects constitute an interaction group. At the beginning of the experiment both subjects receive an endowment of 20 Swiss Francs (CHF 1 ∼ US-$ 0.8). One person is assigned the role 4 of the first mover, the other the one of the second mover, respectively. The first mover decides how much of his endowment to transfer to the second mover. The transfer can be any amount in steps of 2 Swiss Francs, i.e., 0, 2, 4, ..., or 20 Francs. The chosen transfer is tripled by the experimenter and passed to the second mover. Contingent upon the first mover’s transfer the second mover decides on a back transfer to the first mover. This back transfer can be any integer amount between 0 and 80 Swiss Francs. Given the back transfer of the second mover incomes are determined: the first mover earns his endowment minus his own transfer plus the back transfer of the second mover. The second mover gets his endowment plus 3 times the first mover’s transfer minus the back transfer. Our design differs in important ways from previous trust experiments. Since we are mainly interested in discrimination based on group affiliation we add concrete context to the decision environment. In particular, first movers could condition their investment decision on the residential district of the second mover. When they took their decision, they did not yet know the residential district of their second mover. Therefore they had to make twelve investment decisions, one for each of the 12 districts of Zurich. First movers made their decisions with the help of a table with twelve rows (see Table 1). The first column of this table stated the following question: “Suppose the other person lives in district ... . How much of your CHF 20 do you invest? ”. In the second column first movers indicated how much they invest if the second mover lives in district 1, in district 2 etc. up to district 12. In Column (3), first movers were also asked to state their beliefs about the second movers’ repayment decision for each of the twelve districts. Thus first movers made 12 investment decisions and indicated 12 beliefs, one for each district. Knowing first movers’ beliefs is important as it allows us to calculate expected returns on investments and to distinguish between different motivations behind investments. We can identify, e.g., whether high investments are made in the expectation of high back transfers or simply reflect a desire to be altruistic. The instructions also contained a map of Zurich, which displayed the district borders as well as the names of the neighborhoods in each district (see Figure 1). Notice, however, that we did not provide subjects with any statistical information concerning the districts’ characteristics. Thus, any observed differentiation across districts is based on the subjects’ everyday knowledge about Zurich. The fact that first movers made multiple decisions may raise concerns about a potential experimenter demand effect. One could argue that by presenting twelve options, subjects were induced to differentiate their investment decisions biasing our results in favor of discrimination. While this is a potentially important concern we are quite confident that it does not compromise our findings. First, previous discrimination studies have 5 argued against a contingent elicitation procedure because it would underestimate the amount of discrimination, simply because subjects may not like to reveal that they are discriminating. Second, independent of the level of discrimination our method does not induce a particular pattern of discrimination. In other words, if subjects were simply induced to choose different investments in different rows, the resulting pattern would not be systematic but random. Even more important, multiple observations for each individual provide us with valuable information, which is why we chose to implement this procedure. It enables us to classify individuals as discriminators (if investments vary across districts) or non-discriminators (if investments are all the same). This classification is necessary to identify individual determinants of discrimination. The same argument can be made with respect to our interest in studying in-group favoritism: since first movers invest in all districts, including their own, we can easily identify whether first movers perceive strangers from their own district as more or less trustworthy than strangers from other districts. Moreover, we are able to study individual determinants of such an in-group favoritism. In order to elicit second movers’ willingness to reciprocate, we used the contingent response method. This means that each second mover, before knowing the actual first mover’s investment, made a back transfer decision for each of the 11 possible investments (0, 2, ..., 20). Whether this method overestimates or underestimates people’s willingness to reciprocate is an open question.4 For our purpose, however, the contingent response method provides reliable information about second movers’ willingness to reciprocate, which is key for calculating the level of reciprocation on a district level as well as understanding individual determinants of reciprocation. Moreover, we are not predominantly interested in the level of reciprocity but in the differences across districts, which should not be confounded by the usage of this elicitation method. Finally, since the strategy method allows for the simultaneous elicitation of first and second mover decisions it also facilitated the procedures of our experiment considerably. Our mailing also included a questionnaire to elicit detailed information about socioeconomic and individual background of participants. In the cover letter it was emphasized that the questionnaire was part of the experiment and had to be completed. The questionnaire asked about personal attributes like gender, age, marital status, profession, nationality and number of siblings. In addition we elicited information about the personal and residential background of participants: political orientation, duration of residency in 4 For example, Güth et al. (2001) report behavioral differences between a game where subjects played a game sequentially vs. playing the strategy method. On the other hand, Brandts and Charness (2000) and Cason and Mui (1998) report evidence indicating that the strategy method does not induce different behavior. 6 district and city, how closely associated subjects feel with their district and city, number of phone calls during last week, whether subjects are afraid of crime in their district and number of club memberships. In addition to the information collected with the help of the questionnaire, we also received individual background information from the Statistical Office of Zurich. Together with the random sample of address files which we needed to run the study, we received a set of individual characteristics of the participants such as taxable income, gender, age, type of profession, religious affiliation, number of children and foreigner status. This data is of great value as it allows us to complement our questionnaire data and to verify its accuracy. The Statistical Office of Zurich also provides very detailed information about district characteristics. In the results section we use several of these characteristics, such as median per capita income, fraction of foreigners or religious background (see Table 4). 2.2 Experimental Procedures Our subjects are a random sample of the city of Zurich, implying that our subject pool exhibits much greater variance with respect to socioeconomic and personal background than the typically used student samples. This feature of our data is a prerequisite to investigate the impact of person specific characteristics on trust, discrimination and trustworthiness in a meaningful way. For logistical reasons the experiment was conducted via mail correspondence. The Statistical Office of Zurich provided us with address files for each of the twelve city districts of Zurich. The address files constituted a random sample of the population of each district. In total 986 persons took part in the experiment (509 first movers and 477 second movers). All potential participants received a mailing including a cover letter, detailed instructions, a decision sheet and a questionnaire. The cover letter informed subjects about the possibility to take part in a paid experiment, conducted by the University of Zurich. In order to enhance the credibility that we would actually pay subjects we added the remark that the Legal Service of the University (Rechtsdienst) guarantees that the study is run exactly according to the rules stated in the instructions. We also made clear to subjects that the study was run in accordance with the data protection legislation of the city of Zurich. In particular, we stated that all data will be used only for scientific purposes and not given to any third parties. Moreover, we guaranteed that data will be stored in anonymous form and that any information specific to persons will be destroyed after the data collection will be completed. We offered participants to send us an email (using a neutral University email address) or to call us, in order to answer potential questions. Only very few people made use of these options. The instructions explained the idea and 7 the rules of the experiment in detail. First and second movers were told that they were matched with another anonymous person who was randomly selected and lives in Zurich. Participants had to complete the questionnaire and the decision sheet, i.e., first movers filled out the table concerning investments and beliefs and second movers filled out the table concerning back transfers. Subjects then returned the completed decision sheet to us, using a pre-stamped envelope. It was made clear in the cover letter that the decision sheets had to be returned before the end of a deadline, which was about one week after subjects had received their letter. Among all participants we randomly formed pairs. Given the district of the second mover we determined the respective investment of the first mover. Using the investment we then checked the corresponding back transfer.5 In a second mailing all participants were informed about the outcome of the experiment, including the district of the second mover, the investment and back transfer decisions and the resulting payoffs for both players. The second mailing also contained the payments in a sealed envelope.6 2.3 The Newspaper Study In order to get additional and independent information about the systematics and robustness of our discrimination results from the field experiment we ran an additional newspaper experiment. Several months after we had collected the data from our field experiment we contacted a large daily newspaper in the Zurich area, the Tages-Anzeiger. We decided to publish two articles in the newspaper. The first one reported in detail aims and design of the study. In particular, we explained the rules of the experiment and the fact that randomly drawn people from all districts of Zurich had taken part in the study. The first article did not mention any result, however. Instead readers were invited to take part in a quiz. They were asked to answer the following two questions: (1) What do you think, which are the two districts that received the lowest investments? (2) What do you think, which are the two districts that received the highest investments? To guarantee incentive compatibility, we promised to randomly select three readers among all those readers whose answers are correct, and to pay them 200 Swiss Francs. Readers could either email their answers or send them by postcard, within three days after the article had been published. A total of 281 readers took part. The second article appeared one week after the first one and contained the results of our field experiment and the newspaper study. Since there was much public interest in the study, the second article 5 As there were a few more first movers than second movers, some second movers were matched twice. The payoff of these players was determined by the decisions associated with the first match. 6 We deleted all names and address files after having sent the second mailing. 8 also contained an interview with the authors of the study as well as with the mayor of Zurich. 3 Results In this section we present our results. We first investigate prevalence and determinants of trust discrimination. We then explore the nature of this discrimination process by relating the trust reputation of districts to their average level of trustworthiness. In a third step we investigate a particular form of discrimination, in-group favoritism. Finally, we identify determinants of trust discrimination and in-group favoritism on an individual level. 3.1 Discrimination Our first result concerns the level of trust and district specific discrimination. Result 1 (Trust and discrimination) On average first movers reveal a relatively high willingness to trust and invest about 66 percent of their endowment. However, trust levels differ systematically across the residential districts of second movers, i.e., first movers discriminate. Support for Result 1 comes from Figure 2 and Tables 2 and 3. Figure 2 shows a histogram of all investment decisions of first movers.7 The amounts invested are comparable to what has been observed in laboratory studies and reveal that the citizens of Zurich display a relatively high level of trust towards their fellow citizens. On average, first movers invest 13.16 Swiss Francs, which corresponds to 66 percent of their endowment, with a standard deviation of 7.07. In the presence of trust discrimination we should observe that first movers send different amounts of money into different districts. Table 2 shows the average investment levels into each of the 12 districts of second movers. These investments indeed vary: the district with the lowest average investment, e.g., is district 4 while the district that received the highest investment is district 8.8 In terms of magnitude the variation between lowest and highest investments is 11 percent. Thus, the mere fact that someone lives in a district with 7 Since we used the strategy method to collect the decisions, each first mover made 12 investment decisions, one for each of the possible residential districts of the second mover. All these decisions are included in Figure 2. 8 These differences at the aggregate level are the result of the investment behavior of the 55 percent of first movers who discriminate. 45 percent of first movers send the same amount into each district. In Section 3.3 we investigate discrimination at the individual level in more detail. 9 a low vs. a high reputation, reduces received investments by a remarkable amount. In ¢ ¡ back transfer the second row we calculate the expected return on investment = expected −1 investment for each district.9 The resulting levels vary substantially, from 0.15 in districts 4 and 5 to 0.30 in district 1. Moreover, at the district level investments and expected returns on investment are strongly positively correlated, which suggests that different levels of investments are in fact driven by different expectations concerning the districts’ levels of trustworthiness (Spearman’s rho = 0.863, p < 0.001).10 Table 3 reveals that the investment differences displayed in Table 2 are significant for most district comparisons. This table reports the p-values of Wilcoxon-signed-rank tests conducted for pairs of districts. In the table districts are sorted by the level of received average investment. For example, investments into districts 4 and 12, the two districts with the lowest reputation, are not significantly different. Neither are districts 4 and 5 significantly different. However, from district 9 up to district 8, all districts received significantly higher investments than district 4. In total we find that out of the 66 possible comparisons, 51 are significant at least at the 5 percent level.11 How robust and systematic is the ranking of the districts’ trust reputation shown in Table 2? Does it reflect a stable and commonly held perception of district reputation or is this ranking rather arbitrary? A good test for the systematics of the ranking is to ask inhabitants of Zurich and check whether they are able to predict it. This is what we did in our newspaper study. As outlined in more detail in section 2.3, we asked the readers of a large daily newspaper from Zurich to assess which are the two districts that received the lowest and highest investments, respectively. 281 readers took part in this incentive compatible study. Their answers are shown in Figure 3. The grey bars indicate the fraction of readers who think that a specific district is among the two districts that received the lowest investments, the black ones represent the respective fraction of readers 9 We calculate the expected return on investment for each single positive investment decision of first movers. In cases where investments are zero, no meaningful values can be calculated. These observations are therefore neglected (7 percent of our observations contain investments equal to zero; in 91 percent of these cases expected back transfers are zero as well). 10 Since first movers not only state their investment decision for each district but also their belief about the second mover’s back transfer, we can also check whether first movers who do not discriminate, i.e., who send the same amount to all districts expect different back transfers from each district. We find that among those first movers who do not discriminate, 37 percent indicate varying beliefs, i.e., they expect district specific levels of trustworthiness. When we compare this belief based ranking with the one that results from the differences in investments (see Table 2) we find a positive and significant correlation (Spearman’s Rho = 0.59; p = 0.041). This finding reinforces the systematics of discrimination across different districts. 11 An alternative way to show the significance of the investment differences across districts is to simply regress the first mover investments on district dummies (robust standard errors, clustering on individuals). An F-Test shows that district differences are significantly different from zero (p < 0.0001). 10 concerning the two districts with the highest reputation. Districts are displayed on the horizontal axis, ordered according to the actual level of received investments. Figure 3 shows that the newspaper readers predicted the outcome of the experiment extremely well. For example, almost 70 percent think that district 4 is among the two districts receiving the lowest investments and about 50 percent think that this holds for districts 12 and 5, respectively. Almost nobody believes that districts 3 or higher (in terms of actually received investments) are among the two lowest districts. Likewise almost nobody believes that districts 3 or lower (in terms of investments) belong to the group of districts that are among the two districts that received the highest investments. The correlation between the rank order resulting from the answers of the newspaper readers and actual investment ranks is strong and highly significant. For answers concerning the two high investment districts the respective Spearman’s rho is 0.89 (p < 0.0001) while for the two low districts it is -0.88 (p < 0.001). Thus the results from the newspaper study provide strong and independent evidence that districts in Zurich differ significantly and systematically in their perceived trustworthiness. In the next section we analyze potential reasons for these differences. Result 2 (Determinants of trust discrimination) Districts characterized by higher economic status and lower ethnic heterogeneity receive higher investments. In the social capital literature several factors that are associated with trust have been discussed. In this literature subjects from different regions within or across countries are asked about how willing they are to trust strangers. An important difference of this approach with respect to ours concerns the specification of the group that is supposed to be trusted. In the previous literature this group typically remains unspecified and it is not not entirely clear what group concept subjects have in mind when answering the trust question. In contrast, we explicitly fix the group and ask about trustworthiness of a stranger from a specific district of the city of Zurich. Moreover, we are interested in trust discrimination and elicit different levels of trust for different groups. In the following we check whether the factors that have been shown to be relevant for understanding trust in the previous literature also explain group specific trust, i.e., trust discrimination. Some authors have pointed out a positive relation between economic and social status and trust or social capital (Alesina and La Ferrara, 2002; Knack and Keefer, 1997). Another important factor identified in the literature is ethnic and religious heterogeneity (Costa and Kahn, 2002; Alesina and La Ferrara, 2002). The negative correlation between heterogeneity and trust may reflect the fact that each ethnic and religious group is characterized by specific cultural and social norms. The more different norms and cultures are in 11 a district, the more difficult it is to build up social networks and trust. In a similar vein a high degree of mobility and low rates of home ownership have been shown to be negatively correlated with social capital (Glaeser et al., 2002; DiPasquale and Glaeser, 1999; Alesina and La Ferrara, 2002). Finally, it has been argued that members of rather ‘hierarchical’ religions (roman Catholics and Muslims) show relatively low levels of trust. In contrast to the rather liberal tradition of protestant churches, catholic and islamic churches are characterized by strong hierarchies and authorities making it more difficult to establish trust and social capital (La Porta et al., 1997; Knack and Keefer, 1997; Gabriel et al., 2002). Table 4 shows how these variables are distributed across the 12 districts of Zurich. The data is provided by the statistical office of Zurich. Social and economic status is measured by the variables income and high education. Income is the taxable median income per district in 1000 Swiss Francs. High education measures the fraction of people who hold at least a “Matura” degree, an exam that comes at the end of university-track high school in Switzerland and is a prerequisite for attending university. Our measure of ethnic heterogeneity is the fraction of foreigners in a given district. As Column (4) in Table 4 shows, the variation in the fraction of foreigners is quite substantial ranging from 19 percent in district 7 to 44 percent in district 4. Religious heterogeneity is measured with a fragmentation index, i.e., 1 minus the sum of squared fractions of the following religious groups: protestant, catholic, muslim, jewish and other. We measure mobility with the variable years of residency, which shows how long people have lived in their respective district, on average. For example, while the average time lived in district 5 is 6.7 years, people in district 9 live 11.3 years in their district, on average. The variable home ownership shows the fraction of apartments owned by inhabitants. Finally, the variable hierarchical religion measures the fraction of people who are roman catholics. The two rows at the bottom of Table 4 show how the district characteristics are correlated with the mean investments into the districts together with respective p-values of Spearman rank tests in brackets. All coefficients have the expected sign. The correlation for years of residency is insignificant, all others are significant at least at the 5-percent level. For example, the richer a district or the higher educated its inhabitants, the higher its reputation measured in terms of received investments. Likewise, the higher the degree of heterogeneity the lower the trust reputation. Table 5 explores the determinants of trust discrimination in more detail. It shows OLS-regressions where the first mover investments are regressed on district specific characteristics. The dependent variable contains 12 investment decisions per first mover; robust standard errors (in brackets) allow for clustering at the individual level. Note that it makes little sense to run multivariate regressions, regressing investments on all district 12 characteristics simultaneously. The reason is that most of the characteristics are highly correlated and there are only 12 districts to identify the effects. For example, the correlation between income and fraction of foreigners is strong and highly significant (Spearman’s rho=-0.84, p < 0.001). We therefore chose the following estimation strategy. We selected the two variables that are most strongly correlated with investments, income and fraction of foreigners, and show that they are highly significantly correlated with investments, even jointly (see Columns (1) to (3) of Table 5). In Columns (4) to (8) of Table 5 we include all other variables but only one at a time. It turns out that income and ethnic heterogeneity remain highly significant while all other variables are insignificant. The results therefore suggest that economic status and ethnic heterogeneity are important determinants of a district’s trust reputation. Living in a district with a high economic status and a low level of ethnic heterogeneity implies receiving higher investments. Controlling for these two factors all other district characteristics are of less importance. We now turn to the behavior of second movers. We first study whether second movers reciprocate the trust of first movers. In a second step we explore the nature of district specific discrimination and correlate trust and reciprocation at the district level. Result 3 (Back transfers) On average, second movers are reciprocal: the higher the first mover investments, the higher are the back transfers. Moreover, the level of the back transfers exceeds first movers’ expectations. Support for Result 3 comes from Figure 4. It shows averages of expected and actual second mover back transfers for each possible first mover investment. The dark bars show the reciprocal repayment pattern of second movers. It is obvious from Figure 4 that higher investments are reciprocated with higher back transfers. Moreover, the extent of reciprocation is quite high. Compared to student populations where the returns on investment are often close to zero (see, e.g., Camerer (2003), p. 86, and the references therein), second movers from our non-student subjects pool reveal a relatively strong reciprocal inclination. For example, second movers are willing to send back about 35 Swiss Francs if they received 20 Francs. This means that they almost equalize final payments. Over the whole range of investments the slope between investment and pay backs estimated from a simple OLS-regression is about 1.6. Figure 4 also shows that first movers expect reciprocation on the side of the second movers (grey bars). The more they invest, the more they expect to get back. They also expect to get back more than they invest. For example, those who send 20 Swiss Francs expect a back transfer of 27 Francs, on average.12 Comparing expectations and actual 12 This also suggests that high investments are made in the expectation of high back transfers and are not predominantly driven by the desire to be simply altruistic. 13 back transfers reveals that the average level of reciprocation is systematically higher than expected by first movers. In other words first movers generally underestimate the amount of reciprocation that is prevalent in the population of Zurich. Turning to second mover behavior on a district level, we now check whether reciprocation varies across districts and, in particular, whether there is a correlation between investments and the level of reciprocation: Result 4 (Statistical discrimination) Different levels of investment into districts as well as expected returns on investment are both significantly correlated with respective back transfers. This indicates that first movers’ investment decisions are at least in part motivated by statistical discrimination and not just by mistaken stereotypes. We know already that investments into districts correspond to different levels of expected returns on investment (see Table 2). In this sense we can already say that investments are not purely taste driven but actually reflect different levels of expected trustworthiness. In this section we go one step further, however, and ask whether investments and expected returns are actually correlated with back transfers. In other words we investigate whether the observed different expectations merely represent mistaken stereotypes or whether they are actually justified in terms of different levels of trustworthiness. In order to assess a district’s trustworthiness we aggregate people’s back transfers in a given district. In order to so, we cannot only use those back transfers that were actually executed and paid, because even if reciprocal inclinations across districts would be identical, we would find that districts that receive high investments return more than districts that receive low investments. Instead we use data from the contingent response method, which informs us about willingness to reciprocate independent of actual investments. In a first step, we calculate for each subject the relation between investment and back transfer: running simple OLS regressions of back transfer on investment and forcing the slope through the origin we get an estimate of a subject’s reciprocal inclination.13 The higher the estimated coefficient the more sensitive is a second mover’s reaction to varying levels of investments. In a next step, we calculate the averages of these slope for every district. The resulting variation is quite substantial and ranges from about 1.4 to about 2. Figure 5 displays how these district averages are associated with average investments into the respective districts. The numbered dots represent the 12 districts, the dashed line is a weighted linear trend. Figure 5 shows that investments and back transfers are positively and significantly correlated on a district level (Spearman’s rho = 0.67, p 13 We also estimated reciprocal inclinations using individuals’ average back transfers for all possible investments. Qualitatively this yields the same result. 14 < 0.02). Moreover, mean trustworthiness of districts is also correlated with expected return on ivestment (see third row of Table 2). The respective Spearman rank correlation between expected return on investment and average level of reciprocation on a district level is 0.7113 (p < 0.01). This brings us full circle: first movers hold particular beliefs about the trustworthiness of different districts, which determine their trusting decisions. These beliefs correspond on average with actual trustworthiness. 3.2 In-group Favoritism A particular form of discrimination is in-group favoritism, i.e., the tendency to favor strangers who belong to one’s own group. While the relevance of in-group favoritism is well established for simple allocation tasks (see Yamagishi et al., 1999), the literature is yet quite inconclusive about the existence, importance and determinants of in-group favoritism in the context of trust decisions. In trust experiments conducted on the basis of the minimal group paradigm the evidence in favor of an in-group bias is weak. Buchan et al. (forthcoming) and Güth et al. (2005) conducted trust games within and across minimal groups. While Buchan et al. (forthcoming) find some in-group favoritism in trust for American students but not for Chinese students, Güth et al. (2005) don’t find any indication of an in-group bias at all. Similarly, studies based on naturally defined groups provide rather mixed evidence. The discrimination pattern identified in Fershtman and Gneezy (2001) is not a consequence of an ingroup bias. Both, Ashkenazic and Eastern males invest less money if their opponent is an Ashkenazic male. In their trust game study among Harvard undergraduates Glaeser et al. (2000) find that in pairs with participants from different countries or races trust and trustworthiness are lower, but the effect is only of statistical significance for the latter. Bouckaert and Dhaene (2004) report results from trust games with small businessmen of Turkish or Belgian origin in the city of Ghent. Their data does not contain any evidence for the existence of ethnic discrimination or in-group favoritism. Haile et al. (2006) conducted trust experiments with students from two South African Universities. While they do not find evidence for in-group favoritism in total, they observe that low income subjects of both races trust high income subjects from the other race significantly less. Two exceptions that provide evidence in favor of ingroup-favoritism are Bernhard et al. (2006) and Götte et al. (2006). The former is an experiment with two non-hostile clans in Papua New Guinea. First movers in a trust game transfer significantly more to members of their own clan. The latter reports results from experiments with officer candidates in the Swiss Army. Subjects show higher levels of cooperation in a simultaneous prisoner’s dilemma when they interact with a member of their own platoon. 15 Our field experiment offers an ideal set-up to study in-group favoritism in a natural environment. Since first movers make investments for each possible residential district of the second mover, including their own district, we can assess the extent of in-group favoritism by comparing investments into own district relative to other districts. Result 5 (In-group favoritism) We observe a pronounced in-group bias in trust. First movers invest significantly higher amounts into their own districts compared to other districts. Result 5 is supported by the fact that 11 out of the 12 districts invest more to their own district than they invest on average to the other districts. Finding this outcome in the absence of in-group favoritism is very unlikely (Binomial test, p < 0.01). In Table 6 we explore the nature of in-group favoritism in more detail. In the first column we regress first movers’ investments on a dummy for own district, which takes value 1 if the particular investment is meant for the own district and 0 otherwise. The coefficient is positive and highly significant, revealing that first movers systematically favor their own district over other districts. On average they invest 1.40 Swiss Francs more into their own district, which is about 10 percent more than they send on average into the other districts. It turns out that the observed in-group favoritism in trust is in part driven by different expectations about trustworthiness. In Column (2) we regress expected back transfers on the own district dummy. In addition we control for investments. The dummy coefficient is positive and highly significant, suggesting that in-group favoritism is partly explained by different expected levels of trustworthiness: for a given investment, subjects believe that back transfers are 1.08 Francs higher if they interact with strangers from their own district compared to interactions with strangers from other districts. Put differently, people believe that fellow citizens from their own district are more trustworthy than the average citizen, which means that in-group favoritism does not just reflect a particular taste to favor members of one’s own group. 3.3 Individual Determinants of Discrimination and In-group Favoritism Little is known about individual determinants of discrimination and in-group favoritism. Due to a lack of appropriate behavioral data and insufficient variation in personal characteristics of student subject pools, previous work has mainly focused on establishing average effects. In this last results section we combine behavioral data from the contingent re- 16 sponse method with individual background data, and explore individual determinants of discrimination and in-group favoritism. We first examine personal characteristics of people who discriminate in our trust experiment. Overall, 55 percent of the first movers differentiate their investments, while 45 percent send the same amount into each district. Those who discriminate are significantly less trusting than those who don’t. Discriminators send on average CHF 9.47, which is significantly less than the amount sent by those who don’t discriminate (CHF 17.65). In columns (1) to (3) of Table 8 we estimate Probit models, where the dependent variable is an indicator variable, which takes value one if the respective first mover has discriminated and zero otherwise. All estimation results are based on robust standard errors. In the first column we regress the indicator variable on a non-linear specification for age, gender and whether the first mover is an only child. We find no gender and only child effects but a strong age effect. Older people are more likely to discriminate than younger people. In Columns (2) and (3) we add individual characteristics that are influenced by a person’s choices in life. These variables are potentially endogenous and therefore not easy to interpret in a causal way. Column (2) includes variables on income, education, marital status, the number of children, and whether the first mover is a foreigner. In Column (3) we add ideological, religious and attitudinal variables. We find that education and having children reduces the amount of discrimination, while those who classify themselves politically as right-wingers tend to discriminate more. Interestingly, discrimination is neither associated with the time a first mover has lived in Zurich or in his district nor with how associated he feels to Zurich or his district, respectively. In Columns (4), (5) and (6) of Table 8 we study individual characteristics that potentially explain in-group favoritism. We report OLS-estimates where the dependent variable is the individual in-group bias, i.e., the difference between a first mover’s investment into his own district and his average investment into the other districts. In Column (4) the explanatory variables are age dummies and two dummies for gender and only child. None of the coefficients is significant. We add further explanatory variables in Columns (5) and (6), analogously to Columns (2) and (3). Again, none of the variables is significant, with one exception: first movers who feel closely associated to their own district display significantly stronger in-group favoritism.14 These results suggest that in-group favoritism in terms of trust is not a particular gender or age specific phenomenon. Moreover, family, religious or political background 14 The exact wording of the question, which we asked in the questionnaire reads as “How strongly associated do you feel with your city district?” Answers could be given on a five point scale, ranging from ‘not at all’ to ‘very strongly’. We constructed a dummy, which takes value one if a subject answers the question with ‘very strongly’ and zero otherwise. 17 don’t seem to matter. What does matter – quite intuitively – is the nature of the relationship with the particular in-group. People who identify with their group and state that they feel associated favor in-group members over members from other groups, even in anonymous interactions. 4 Concluding remarks In this paper we study prevalence and determinants of discrimination, in-group favoritism and trust and reciprocity across different districts of Zurich. Many people discriminate and trust strangers from different districts differently. Given that Zurich is a relatively homogenous city, in comparison with many other cities, it is quite striking to find discrimination even here. We speculate that discrimination is even more pronounced in more heterogenous cities or regions. Our data reveal that first movers hold particular beliefs about the trustworthiness of different districts, which are associated with their trusting decisions. These beliefs correspond on average with actual trustworthiness. This is a strong result. It implies that first movers know quite a lot about their city and use this information to determine their decisions. As a consequence, first movers invest more into districts that are actually characterized by higher levels of trustworthiness. In this sense, we can interpret the observed discrimination pattern, at least in part, in terms of statistical discrimination. Rather than being only driven by taste or prejudice, many people in the city of Zurich discriminate on the basis of their relatively accurate beliefs. We also find strong support for the existence of in-group favoritism in trust. Citizens of Zurich tend to favor strangers from their own district, in part because they expect them to be more trustworthy than strangers from other districts. The fact that people discriminate between strangers from different districts can have important economic and social consequences, not only for an individual living in a particular district but also for districts as a whole. On an individual level it is relevant insofar as many economically relevant transactions involve some element of trust. In the hiring process, e.g., two otherwise equal applicants may be treated differently simply because they come from different parts of the city. On the level of districts, trust discrimination may foster the process of segregation. The Zurich case shows that districts with a relatively high socio-economic status are also those, which enjoy the highest reputation of being trustworthy. Since this reputation favors investments there is an endogenous tendency to reinforce inner city inequalities. Relatively richer districts are trusted more and therefore become even richer. This process is reinforced by housing rents and moving decisions. Those who can afford it will move to high reputation districts, again increasing 18 district inequalities. Our results are also relevant from a city development point of view. The study demonstrates that policy makers can use field experiments to identify the reputation of different neighborhoods in a way that is relevant for the citizens of the respective city or region. Running similar experiments could help identify problem areas in a cheap and reliable way. 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Walker (eds), Advances in Group Processes, Volume 16, Jai Press Inc., pp. 161–97. 22 Figure 1: Map of Zurich as distributed to participants 23 0 .1 Relative frequency .2 .3 .4 Figure 2: Histogram of first mover investments 0 2 4 6 8 10 12 Investments 24 14 16 18 20 Fraction of participants in the newspaper study .1 .2 .3 .4 .5 .6 .7 .8 Figure 3: Answers of newspaper readers 0 High Low 4 12 5 9 11 3 2 1 Receiving districts 25 10 6 7 8 Average back transfer 10 15 20 25 30 35 Figure 4: Actual and expected second mover back transfers 0 5 Exp. back transfer Back transfer 0 2 4 6 8 10 12 Investment 26 14 16 18 20 2.2 Figure 5: Correlation of investments and reciprocal inclination Mean reciprocal inclination 1.6 1.8 2 1 6 7 2 8 9 5 10 3 4 11 1.4 12 12.5 13 13.5 Mean received investment 14 Notes: Each numbered dot in the figure corresponds to one of Zurich’s districts. The line represents the predicted values for the mean reciprocal inclination based on a linear regression of mean reciprocal inclination on mean received investments. 27 Table 1: Decision table for first movers Suppose the other person lives in district 1 2 ... 12 How much of your CHF 20 do you invest? 28 How much do you expect to get back? Table 2: Average investment into districts and expected back transfers Into district Investment Expected back transfer Expected return on investment1 1 2 3 4 5 6 13.41 13.30 13.04 12.44 12.50 13.72 18.22 17.43 16.73 15.12 15.26 18.15 0.30 0.23 0.24 0.15 0.15 0.24 Into district Investment Expected back transfer Expected return on investment1 7 8 9 10 11 12 13.74 13.83 12.90 13.68 12.91 12.45 17.87 18.17 16.07 17.63 15.96 15.07 0.25 0.25 0.19 0.23 0.17 0.16 ´ ³ back transfer We calculate the expected return on investment = expected − 1 for each single investment positive investment decision of first movers. Note that in cases where investments are zero, no meaningful values can be calculated. These observations are therefore neglected (7 percent of our observations contain investments equal to zero; in 91 percent of these cases expected back transfers are zero as well). 1 29 Table 3: Pair-wise comparison of investments into districts Districts 4 12 5 9 11 3 2 1 10 6 7 12 0.99 5 9 11 3 2 0.20 0.00 0.00 0.00 0.00 0.35 0.00 0.00 0.00 0.00 0.01 0.01 0.00 0.00 0.86 0.20 0.00 0.10 0.00 0.03 1 0.00 0.00 0.00 0.01 0.01 0.10 0.80 10 0.00 0.00 0.00 0.00 0.00 0.00 0.01 0.17 6 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.57 7 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.01 0.22 0.43 8 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.03 0.65 0.53 0.89 Notes: The table reports p-values of pair-wise Wilcoxon-signed-rank tests. The units of observation are individual first mover investments. Districts are ordered by received investments such that districts with similar received investment are located close to each other. 30 31 Income 39 40 35 30 36 40 44 42 36 40 36 31 0.92 [0.000] High education2 0.48 0.33 0.26 0.25 0.30 0.44 0.47 0.44 0.19 0.33 0.24 0.15 0.83 [0.001] Foreigners 0.22 0.23 0.33 0.44 0.39 0.23 0.19 0.25 0.33 0.25 0.33 0.35 -0.85 [0.000] 3 Religious heterogeneity4 0.68 0.72 0.72 0.71 0.71 0.69 0.68 0.69 0.70 0.70 0.71 0.71 -0.65 [0.022] Years of residency5 8.1 10.9 9.4 7.7 6.7 9.9 10.8 10.0 11.3 10.3 9.4 11.0 0.18 [0.572] Home ownership6 0.09 0.06 0.04 0.04 0.06 0.06 0.13 0.08 0.05 0.09 0.06 0.04 0.74 [0.006] Notes: Source: Statistical Office of Zurich and Statistical Yearbook of the City of Zurich (2003) 1 median per capita income in 1000 Swiss Francs (data for unmarried persons only) 2 population fraction with at least a ”matura” degree (prerequisite for attending university) 3 population fraction of foreigners 4 fragmentation index = 1 - sum of squared population fractions of all religions 5 average number of years with residency in the same district per person 6 fraction of apartments owned by inhabitants 7 population fraction of Catholics 8 Spearman’s Rho for the correlation of first mover investments and the variable (p-values in brackets) District 1 2 3 4 5 6 7 8 9 10 11 12 Spearm. Rho8 1 Table 4: District characteristics Catholics7 0.27 0.31 0.33 0.36 0.32 0.32 0.28 0.31 0.37 0.32 0.35 0.34 -0.75 [0.005] 32 8.928*** [0.616] YES 6087 0.85 (1) 0.113*** [0.017] 14.981*** [0.280] YES 6087 0.85 -6.239*** [0.952] (2) 11.740*** [0.892] YES 6087 0.85 (3) 0.063*** [0.018] -3.150*** [1.134] 11.889*** [0.881] YES 6087 0.85 (4) 0.051*** [0.020] -2.954** [1.168] 0.677 [0.747] 10.547*** [1.432] YES 6087 0.85 4.252 [3.691] (5) 0.058*** [0.018] -2.803** [1.168] Received investment 11.716*** [1.155] YES 6087 0.85 0.001 [0.038] (6) 0.063*** [0.018] -3.129** [1.253] 11.263*** [0.926] YES 6087 0.85 -3.869 [2.485] (7) 0.082*** [0.021] -3.197*** [1.135] 2.268 [2.285] 11.085*** [1.081] YES 6087 0.85 (8) 0.065*** [0.018] -3.694*** [1.281] Notes: OLS-estimation with robust standard errors clustered on individuals in brackets. The dependent variable contains 12 investment decisions per first mover (one for each district). Details on the independent variables are found in Table 4. * significant at 10%; ** significant at 5%; *** significant at 1%. Individual fixed effects Observations R-squared Constant Roman catholics Home ownership Years of residency Religious heterogeneity High education Foreigners Income Dependent variable Table 5: Determinants of received investments at the district level Table 6: First mover’s in-group bias Dependent variable Own district Investment Exp. back transfer (1) 1.396*** [0.160] (2) 1.076*** [0.247] 1.097*** [0.067] 2.294*** [0.872] YES 6086 0.89 First mover’s investment Constant Individual fixed effects Observations R-squared 13.032*** [0.013] YES 6087 0.85 Notes: OLS-estimations with robust standard errors clustered on individuals in brackets. The dependent variables contain 12 observations (investments resp. expected back transfers) per first mover (one for each district). * significant at 10%; ** significant at 5%; *** significant at 1%. We lose one observation in Column (2) due to a non-response. 33 Table 7: Definitions of variables (personal chararacteristics) Age X-Y Female Only Child Tax Income High skilled Married Children Foreigner Years of residency in city Associated with city Years of residency in district Associated with own district Rightwinger Leftwinger Catholic Protestant Other religion Dummy variable that takes on the value 1 if the person is in the age range X to Y and 0 otherwise. Dummy variable that takes on the value 1 if the person is female and 0 otherwise. Dummy variable that takes on the value 1 if the person does not have siblings. Taxable income as reported to the tax authorities of Zurich (in 10’000 Swiss Francs). As married couples only report their combined income to the authorities, we divide the reported value by 2 in case of married people. Dummy variable that takes on the value 1 if the person has a ISCO skill level of 4 and 0 otherwise. The International Standard Classification of Occupations (ISCO-88) organizes occupations in an hierarchical framework and assigns a skill level (1 (elementary occupations) to 4 (professionals)) to each occupation. Dummy variable that takes on the value 1 if the person is married and 0 otherwise. Number of children of the person Dummy variable that takes on the value 1 if the person is not a Swiss citizen and 0 otherwise. Number of years that the person has lived in the city of Zurich. Dummy variable that indicates whether the person feels strongly associated with the city of Zurich; originally measured on a four-point scale from 1 (not at all) to 4 (very strongly). The dummy takes on the value 1 if the person has ticked “very strongly” and 0 otherwise. Number of years that the person has lived in the current district of residency. Dummy variable that indicates whether the person feels strongly associated with her district of residency; originally measured on a four-point scale from 1 (not at all) to 4 (very strongly). The dummy takes on the value 1 if the person has ticked “very strongly” and 0 otherwise. Dummy variable that indicates whether the person conceives herself as a rightwinger; originally measured on a five-point scale from 1 (leftwing) to 5 (rightwing). The dummy takes on the value 1 if the person has ticked “rightwing” and 0 otherwise. Dummy variable that indicates whether the person conceives herself as a leftwinger; originally measured on a five-point scale from 1 (leftwing) to 5 (rightwing). The dummy takes on the value 1 if the person has ticked “leftwing” and 0 otherwise. Dummy variable that takes on the value 1 if the person is a roman Catholic and 0 otherwise. Dummy variable that takes on the value 1 if the person is a Protestant and 0 otherwise. Dummy variable that takes on the value 1 if the person reports a confession other than Catholic or Protestant (but not no confession) and 0 otherwise. 34 Table 8: Individual determinants of discrimination and in-group favoritism Dependent variable Age 31-45 Age 46-60 Age 61-75 Age 76 and older Female Only child Discrimination (1) -0.027 [0.168] 0.175 [0.188] 0.691*** [0.219] 0.955*** [0.300] 0.05 [0.125] 0.113 [0.182] (2) 0.049 [0.181] 0.213 [0.201] 0.568** [0.246] 0.727** [0.359] 0.041 [0.133] 0.027 [0.192] 0.001 [0.016] -0.362*** [0.125] 0.042 [0.150] -0.148* [0.083] 0.249 [0.228] -0.116 [0.154] 491 0.019 [0.178] 470 Tax Income High skilled Married Children Foreigner Years of residency in city Associated with city Years of residency in district Associated with own district Rightwinger Leftwinger Catholic Protestant Other religion Constant Observations R-squared In-group Bias (3) 0.051 [0.190] 0.291 [0.220] 0.551* [0.289] 0.752* [0.428] 0.021 [0.138] -0.02 [0.195] -0.01 [0.017] -0.327** [0.128] 0.035 [0.153] -0.151* [0.083] 0.257 [0.234] 0.003 [0.006] 0.124 [0.136] -0.003 [0.007] 0.086 [0.182] 0.822** [0.392] -0.211 [0.162] 0.087 [0.198] -0.303 [0.190] -0.161 [0.217] 0.092 [0.251] 467 (4) -0.774 [0.480] -0.593 [0.538] 0.298 [0.606] 0.509 [0.767] 0.136 [0.353] 0.344 [0.516] (5) -0.722 [0.512] -0.601 [0.570] 0.327 [0.672] 0.392 [0.938] 0.109 [0.374] 0.614 [0.538] 0.026 [0.047] -0.35 [0.352] -0.052 [0.416] -0.047 [0.224] 0.183 [0.632] 1.713*** [0.441] 491 0.02 1.771*** [0.507] 470 0.02 (6) -0.647 [0.527] -0.561 [0.612] 0.285 [0.795] 0.13 [1.123] 0.047 [0.380] 0.573 [0.548] 0.034 [0.050] -0.391 [0.358] -0.02 [0.422] -0.11 [0.228] 0.295 [0.651] 0.008 [0.015] 0.255 [0.381] -0.007 [0.018] 1.433*** [0.519] -0.226 [0.973] 0.137 [0.447] -0.242 [0.545] -0.597 [0.529] -0.38 [0.600] 1.712** [0.690] 467 0.05 Notes: Columns (1) to (3): Probit estimations with robust standard errors in brackets. The dependent variable is an indicator variable that takes the value 1 if the first mover has discriminated and 0 otherwise. Columns (4) to (6): OLS-estimations with robust standard errors clustered on individuals in brackets. The dependent variable is the difference between a first mover’s investment into his own district and his average investment into other districts. Details on the independent variables in all regressions of this table are found in Table 7. * significant at 10%; ** significant at 5%; *** significant at 1%. We lose observations in Columns (2), (3), (5) and (6) due to non-responses. 35