The perils of peer punishment: Evidence from a common pool resource framed field experiment

We provide a model and experimental evidence on the effects of non monetary punishment (NMP) by peers among communities of Uruguayan fishers exploiting a common pool resource (CPR). To our knowledge, this is the first study that examines the relevance NMP in a CPR game. We find a) experimental groups composed of fishers from different communities (out-groups) who are sometimes in conflict over fishing did not overexploit the resource more than groups from a single community (in-groups) and unlike in-groups, out-groups reduced their exploitation of the resource in response to the threat of punishment, b) a substantial amount of punishment is targeted on cooperative individuals who respond by increasing their exploitation of the resource; and c); wealthier individuals practiced greater overexploitation of the resource. Our results suggest that the relevance of in-group favoritism in promoting cooperation due to social preferences may be overrated, the effectiveness of peer punishment is greater when individuals are motivated by social preferences and coordination is required to prevent anti-social targeting and to enhance the social signal conveyed by the punishment.