Explaining human cooperation in large groups of non-kin is a major challenge to both rational choice theory and the theory of evolution. Recent research suggests that group cooperation can be explained by positing that cooperators can punish non-cooperators or cheaters. The experimental evidence...

Customary law has been criticized from very different angles. Rational choice theorists claim that what looks like custom is nothing but self-interest. Positivists doubt that anything beyond consent assumes the force of law. In this paper, we adopt an experimental approach to test these claims....

In four independent Chapters, I examine how norms guide our behavior in an uncertain world. Methodologically, I apply the toolbox of experimental economics to research questions that are on the interface between economics and law (especially Chapter 1 and Chapter 2), sociology (especially...