Understanding the proximate and ultimate sources of human cooperation is a fundamental issue in all behavioural sciences. In this article we review the experimental evidence on how people solve cooperation problems. Existing studies show without doubt that direct and indirect reciprocity are...

We study public goods game where the contribution efforts are observable. When the players are observed, they contribute more and free-riding diminishes significantly. On the other hand, presence of an audience does not affect the performance of players if there is no strategic aspect of the...

Monetary incentives are often considered as a way to foster contributions to public goods in society and firms. This paper investigates experimentally the effect of monetary incentives in the presence of a norm enforcement mechanism. Norm enforcement through peer punishment has been shown to be...

Ethical goods are increasingly available in markets for conventional goods giving proethically motivated consumers a convenient option to contribute to public goods. In a previous experiment we explored the behavioural relevance of impure public goods in a withinsubject setting and observed...