Cooperative Behavior and the Frequency of Social Interaction

合作可能符合每个人的长期利益，但在任何单一的社会互动中，每个人都可能有背叛合作行为的动机。 这就是社会困境的本质。 当个体在一种无限期的长期关系中配对时，引发他人对不合作行为的不合作反应的威胁可能足以维持合作行为。 然而，个人可能在一个社区生活很长一段时间，经常与该社区的各种成员互动，但与该社区的任何特定成员只有短期的，间歇性的关系。 在这种情况下，机会主义行为的受害者不可能直接惩罚叛逃者。 尽管如此，坎多里已经证明，在一定条件下，合作行为的社会规范可以通过同样的历史依赖策略来维持，这种策略可以在固定的个体对之间的长期关系中维持合作行为。 Kandori定理是Folk定理在无限重复博弈中的推广。 与民间定理一样，它只证明了合作可以通过依赖于历史的触发策略来维持。 一个群体是否以及在什么条件下会发展出合作行为的社会规范是本研究要解决的问题。具体而言，行为实验已被设计成调查在多大程度上的合作行为，在一个无限重复的囚徒困境阶段的游戏是由匹配技术的性质和字符的信息传递到下一个阶段的游戏的球员发挥的影响。 本研究将比较当固定的两人参与无限期重复的囚徒困境阶段博弈时，与在每个阶段博弈后匿名随机匹配的固定群体中观察到的合作行为的程度。 在随机匹配条件下，参与者对对手过去行为的信息量也会有所不同，从而决定更多的信息是否会导致合作行为的频率增加。（竞争性）在这种环境中，代理人既有随着时间的推移而合作的动机，又有在任何特定时刻机会主义竞争的动机在合作安排必须自我执行的许多情况下，时间的长短显然很重要。 其中包括各种不同的背景，如禁试条约的设计，相对绩效工资制度的设计，以及反垄断法的管理，以处理隐性勾结。 除了这些具有实际重要性的问题之外，这个实验的结果对实验经济学家也具有方法论上的重要性，因为他们经常使用随机匹配协议来研究策略情境中的学习行为，这些策略情境意味着代表一次性的遭遇。 .

Cooperation may be in everyone's long-term interest, but in any single social interaction each individual may have an incentive to defect from cooperative behavior. This is the essence of social dilemmas. When individuals are paired in an indefinitely long-term relationship, the threat of triggering non-cooperative responses by others to a non-cooperative act may be sufficient to sustain cooperative behavior. However, individuals may live in a community for a long time, frequently interact with various members of that community, but have only short-term, intermittent, relationships with any particular member of that community. In such circumstances, it is not be possible for the victim of an opportunistic act to directly punish the defector. Nevertheless, Kandori has shown that, under certain conditions, a social norm of cooperative behavior can be sustained by the same kind of history-dependent strategies that can sustain cooperative behavior in long-term relationships between fixed pairs of individuals. Kandori's theorem is an extension of the Folk Theorem for infinitely repeated games. Like the Folk Theorem, it only proves that cooperation can be sustained by history-dependent trigger strategies. Whether, and under what conditions a group will develop a social norm of cooperative behavior are the questions this study addresses. Specifically, a behavioral experiment has been designed to investigate the degree to which cooperative behavior in an indefinitely repeated prisoners' dilemma stage game is influenced by both the nature of the matching technology and the character of the information transmitted about the play of one stage game to the players of the next stage game. The study will compare the extent of cooperative behavior observed when fixed pairs play an indefinitely repeated Prisoners' Dilemma stage game with that observed in a fixed group that is anonymously and randomly matched after each stage game. In the random matching condition, the amount of information that players have concerning their opponent's past behavior will also be varied so as to determine whether more information leads to increases in the frequency of cooperative behavior.The question of what kinds of social interaction promote or inhibit cooperative (competitive) behavior in environments where agents have both incentives to cooperate over time and incentives to opportunistically compete at any particular moment of time is of obvious importance in many settings where cooperative arrangements must be self-enforcing. These include such diverse settings as the design of test-ban treaties, the design of relative performance pay systems, and the administration of anti-trust laws to deal with implicit collusion. Beyond these matters of practical importance, the results of this experiment are also of methodological importance for experimental economists who often use random matching protocols to study learning behavior in strategic situations that are meant to represent one time encounters. .