Altruistic cooperation

We characterize 'Games of Altruistic Cooperation' as a class of games in which cooperation leaves the individual and the group of decision-makers worse off than defection, but favors individuals outside the group. An example is climate change mitigation. In this context, we experimentally investigate whether decentralized institutions using costly punishment and/or communication support altruistic cooperation to sustain the welfare of future generations. Without punishment or communication, cooperation is low; communication alone even increases the incidence of zero contributions. However, combining peer punishment with communication strongly increases cooperation, showing that an effective decentralized solution to a Game of Altruistic Cooperation exists.