We use epistemic game theory to explore rationales behind cooperative behaviors in the finitely repeated Prisoner’s Dilemma. For a class of type structures that are sufficiently rich, the set of outcomes that can arise when each player i is rational and satisfies \((m_i-1)\)th order strong belief of rationality is the set of paths on which each player i defects in the last \(m_i\) rounds. We construct one sufficiently rich type structure to elaborate on how different patterns of cooperative behaviors arise under sufficiently weak epistemic conditions. In this type structure, the optimality of forgiving the opponent’s past defection and the belief that one’s defection will be forgiven account for the richness of the set of behavior outcomes.

我们使用认知博弈论来探索有限重复囚徒困境中合作行为背后的基本原理。对于一类足够丰富的类型结构，当每个参与者i是理性的并且满足\((m_i-1)\)次强理性信念时可能出现的结果集是每个参与者所走的路径集我在最后一个缺陷\(m_i\)回合。我们构建了一个足够丰富的类型结构来详细说明在足够弱的认知条件下不同的合作行为模式是如何产生的。在这种类型的结构中，原谅对手过去的背叛和相信自己的背叛将被原谅的最佳性解释了行为结果集的丰富性。