Previous experiments have found a moderate, positive effect of group size on cooperation in voluntary contribution mechanism (VCM) games. This effect has been typically observed in experiments with groups of size 4 or more, and contrasts with results from n-person prisoner's dilemma and...

This paper computes the share of all household giving accounted for by the American households donating the largest amounts over the 1960–2012 period. The share of donations accounted for by a minority of top donors has risen sharply over this period. This rising concentration is driven by...

The philanthropic sector is highly consequential, particularly in the United States, and the most important policies directed toward this sector are tax policies. Yet most economic analysis of the optimal tax treatment of charitable giving is ad hoc, treating it as a subject unto itself. This...

We explore whether environmental motivation affects environmental behavior by focusing on volunteering. The paper first introduces a theoretical model of volunteering in environmental organizations. In a next step, it tests the hypothesis working with a large micro data set covering 32 countries...