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 report experimental findings on the role of charitable promises in bargaining settings. We vary the enforceability of such promises within variants of ultimatum games where the proposer suggest a split between himself, the responder and a char-itable donation. By reneging on initial pledges,...