Why do many oppose the selling of human organs if, as economists argue, this would increase supply? Economists see material incentives as key to changing behaviour – and are puzzled if incentives don’t work as expected. For psychologists, social norms explain such behaviour; legal scholars say law can shape society’s norms. CEPR DP8663 tries to reconcile these disparate insights with a unifying theory that could explain puzzles such the aversion to organ-selling as well as why so many people resist economists’ advice.

What are the fundamental causes of differences in income per capita across countries? Although there is still little consensus on the answers to this question, it is often argued that social attitudes such as trust are one of the main determinants of economic development.