The observability of partners' past play is known to theoretically improve cooperation in an infinitely repeated … information per se may not improve cooperation. A structural estimation suggests that a certain percentage of players act …

Evolution of cooperation by reciprocity has been studied using two-player and n-player repeated prisoner’s dilemma … cooperation when less generous, and better at maintaining a long-term cooperation in the presence of rare defectors when more …

facilitate and obstruct cooperation in a repeated prisoners' dilemma game. In finitely repeated games a player who cares only for … infinitely repeated games with two emotional players less patience is required to sustain cooperation. However, emotions can also … obstruct cooperation if they make the players unwilling to punish each other, or if the players become hostile when punished. …

In evolutionary models of indirect reciprocity, reputation mechanisms can stabilize cooperation even in severe … cooperation problems like the prisoner's dilemma. Under certain circumstances, conditionally cooperative strategies, which … lead to a breakdown of this kind of indirectly reciprocal cooperation. Backward induction, however, requires strategies …

equilibrium remains an open question. With restrictions of simple symmetry with eternal mutual cooperation, defection, or (matched …