Unaffected Strangers Affect Contributions

Several recent experimental studies have confirmed that social sanctioning can enforce cooperation in public good situations. These studies consider situations where the participants, who have monetary interest in the outcome of the public good game, inflict social sanctioning. The present experimental study, however, considers behavioral effects of social sanctioning from observers with no monetary interest in the outcome of the public good game. The experiment has two treatment effects. First, each participant’s identity and contribution to the public good is revealed to the observers. Second, we introduce information likely to affect participants’ expectations regarding the observers’ approval or disapproval of contributions to the public good. The data provides some evidence that indirect social sanctioning from these monetarily unaffected observers can increase voluntary contributions to public goods, provided that the participants have reason to believe that the observers have themselves contributed substantially in a similar situation. However, the effect on cooperation is not as strong as effects found in previous studies where participants themselves, and not only monetarily unaffected observers, are able to inflict social sanctioning.