Social Preferences Under the Shadow of the Future

Social interactions predominantly take place under the shadow of the future. Previous literature on infinitely repeated games has highlighted the primary role of self-interested strategic considerations in explaining outcomes. Using indefinitely repeated prisoner’s dilemma games, this paper demonstrates experimentally the importance of social preferences for achieving efficient cooperative outcomes. Sorting agents by their pro-sociality, we find that cooperation is three to four times higher among prosocial players compared to selfish players. We also show that social preferences are less important when individuals interact in mixed populations. This can explain why the influence of social preferences has not been detected in previous studies.