Voluntarily Separable Repeated Prisoner's Dilemma (Fujiwara-Greve and Okuno-Fujiwara, 2009) has many kinds of equilibria. Focusing on monomorphic and bimorphic equilibria, we show that a bimorphic equilibrium consisting of cooperators and defectors is most efficient, under a mild payoff...

In repeated Prisoner's Dilemma, the C-trigger strategy played by all players is well-known to achieve symmetric efficiency when players are sufficiently patient. By contrast, if players are free to quit from a repeated Prisoner's Dilemma without information flow to new partners, cooperation from...