Social Dilemma and Emergence of Cooperation

本研究从具有远见的von Neumann-Morgenstein稳定集的角度来研究囚徒困境和社会困境。主要结果如下：1.囚徒困境：当两个玩家独立行为时，唯一稳定集由两种状态组成：双方合作或双方都有缺陷。如果允许混合策略，则每对混合策略都包含在一个稳定的集合中。当他们被允许交流时，即使协议不具约束力，也存在一个独特的稳定集，由一个结果组成：双方合作。如果玩家使用混合策略，所有稳定的集合都由帕累托最优结果组成。此外，在交替移动的囚徒困境博弈中，静止的均衡为我们提供了与稳定集相似的结果。2社会两难：在社会两难中(多个参与者的囚徒困境)，即使参与者之间没有协议具有约束力，但任何马厩的结果都是帕累托最优的，并且是个人理性的。

This research studies prisoner's dilemma and social dilemma from the standpoint of von Neumann-Morgenstern stable sets with farsightedness of players. The following are the main results.1 Prisoner's dilemma: When two players behave independently, the unique stable set consists of two states: both cooperate or both defect. If mixed strategies are allowed, every pair of mixed strategies is included in a stable set. When they are allowed to communicate, even though agreements are not binding, there exists a unique stable set consisting of one outcome : both cooperate. If players use mixed strategies, all stable sets consist of Pareto optimal outcomes. Moreover, stationary equlibria in an alternating-move prisoner's dilemma game provide us with similar outcomes as stable sets.2 Social dilemma: In a social dilemma (a prisoner's dilemma with many players), even though no agreement among players is binding, outcomes in any stables set are Pareto optimal and individually rational.