Sanction Enforcement among Third Parties:New Experimental Evidence from Two Societies

Sanction enforcement offers the potential to mitigate free riding on punishment among multiple third parties. This paper experimentally studies third-party enforcement of social norms in a prisoner fs dilemma game with and without opportunities for higher-order punishment. Based on insights from the literature on cooperation, kinship and moral systems, we compare people fs sanction enforcement across student subjects in two societies: India and the United Kingdom. The experiment results show that, in both societies, third parties f first-order punishment is most severe for defectors and that a third party fs failure to punish a defector invites higher-order punishment from their fellow third parties. These findings are consistent with a model of social preferences and literature from anthropology and theoretical biology. Further, third-party punishment is stronger in the UK than in India, consistent with the conjecture that people in a society with relatively looser ancestral kinship ties are more willing to engage in pro-social punishment. However, in contrast to the theory or conjecture, there is clear difference in the group size effects between the two research sites: whereas third parties free ride on others f punitive acts in the UK, they punish more when in the presence of other third parties in India.