This paper uses variation in traffic safety laws and obesity rates to identify substitution patterns between living and cadaveric kidney donors. Using panel data from 1988-2008, we find that a 1% decrease in the supply of cadaveric donors per 100,000 increases the supply of living donors per...

We build a theory of prosocial behaviour that combines heterogeneity in individual altruism and greed with concerns for social reputation or self-respect. The presence of rewards or punishments creates doubt as to the true motive for which good deeds are performed, and this ‘overjustification...

This paper is an empirical study of the motives for charitable donations, based on a unique data set of the English National Opera. Merging all their box office and fundraising data, our data set not only contains individuals’ donations, but also their opera attendance and all the fringe...

Gratuitous cooperation (in favour of non-relatives and without repeated interaction) eludes traditional evolutionary explanations. In this paper we survey the various theories of cooperative behaviour, and we describe our own effort to integrate these theories into a self-contained framework....

We run an experiment with users of internet message boards. We find that forum users cooperate more with partners of their own forum than with partners from a different forum but they are equally altruistic when they made a gift to a partner of their forum or from another one. We also find that...