Moral Norms in a Partly Compliant Society

This paper analyses competition of moral norms and institutions in a society where a fixed share of people unconditionally complies with norms and the remaining people act selfishly. Whether a person is a norm-complier or selfish is private knowledge. A model of voting-by-feet shows that those norms and institutions arise that maximize expected utility of norm-compliers, taken into account selfish players' behavior. Such complier optimal norms lead to a simple behavioral model that, when combined with preferences for equitable outcomes, is in line with the relevant stylized facts from a wide range of economic experiments, like reciprocal behavior, costly punishment, the role of intentions, giving in dictator games and concerns for social efficiency. The paper contributes to the literature on voting-by-feet, institutional design, ethics and social preferences.