Explaining human cooperation in large groups of non-kin is a major challenge to both rational choice theory and the theory of evolution. Recent research suggests that group cooperation can be explained by positing that cooperators can punish non-cooperators or cheaters. The experimental evidence...

This paper investigates how the introduction of social preferences affects players’ equilibrium behavior in both the one-shot and the infinitely repeated version of the Prisoner’s Dilemma game. We show that fairness concerns operate as a ”substitute” for time discounting in the...