The impact of peer ratings on cooperation : the role of information and cost of rating

In this study, we experimentally analyze the effectiveness of payoff‐irrelevant peer‐to‐peer ratings as a cooperation enforcement device in a finitely repeated public goods game setting. We run two treatments that differ in the amount of information on own and others' received rating points provided to the players, whereas, in a third treatment, we analyze peer approval when assigning ratings to others is costly. In particular, we wonder whether, even under anonymity and in the absence of reputational concerns, (a) players rate others' contribution decisions in the expected direction and (b) the peer rating mechanisms under study foster cooperation and welfare. Our findings reveal that, in the two costless rating treatments, peer rating concerns lead to higher contributions and efficiency, compared to our control. Introducing a small fixed cost for assigning rating points results in a very high percentage of subjects deciding not to rate others' behavior, so that cooperation cannot be enforced.