Social norms are a ubiquitous feature of social life and pervade almost every aspect of human social interaction. However, despite their importance we still have relatively little empirical knowledge about the forces that drive the formation, the maintenance and the decay of social norms. In...

Throughout human history, informal sanctions by peers were ubiquitous and played a key role in the enforcement of social norms and the provision of public goods. However, a considerable body of evidence suggests that informal peer sanctions cause large collateral damage and efficiency costs....