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

- Framed field CPR experiment with small-scale fishers from coastal lagoons
- We combined a social disapproval treatment with and in-group/mixed-group treatment
- Mixed groups reduce their extraction in response to the threat of social sanctions
- We find no in-group bias with respect to cooperation
- Individuals adjust their extraction levels to match their peers' previous mean

We provide experimental evidence on the effects of social disapproval by peers among communities of Uruguayan small-scale fishers exploiting a common pool resource (CPR). We combined this treatment with an in-group (groups from a single community)/mixed group (groups composed of fishers from different communities) treatment. Our aim is to compare the effects of social disapproval in a context in which individuals exploiting a CPR belong to different communities relative to the case in which only individuals from the same community are allowed to exploit the resource. We find that mixed groups-unlike in-groups-reduce their exploitation of the resource in response to the threat of punishment. We do not find any differences in behavior between in-groups and mixed groups when the possibility of being punished is not available. Both in in-groups and mixed groups there is substantial antisocial punishment, which leads to increased extraction of the CPR by those who are unfairly punished. We interpret that the effectiveness of social disapproval is reduced because cooperation was not perceived as the unique social norm. These findings indicate that effective peer punishment requires coordination to prevent antisocial targeting and to clarify the social signal conveyed by punishment.