This paper investigates the driving forces behind informal sanctions in cooperation games and the extent to which theories of fairness and reciprocity capture these forces. We find that cooperators' punishment is almost exclusively targeted towards the defectors but the latter also impose a...

Informal sanctions are a major determinant of a society's social capital because they are key to the enforcement of implicit agreements and social norms. Yet, little is known about the driving forces behind informal sanctions. We systematically examine the determinants of informal sanctions by a...