Many important social and political goals are at least partially funded by charitable donations (e.g. environmental, public health, and educational). Recently a number of laboratory experiments have shown that a potential donor’s incidental emotions—those felt at the time of the decision but unrelated to the decision itself—are important factors. We extend these findings by examining the effect of incidental emotions on charitable giving using a natural field experiment, where the potential donors are unaware of the intervention. In partnership with a (...) pledge drive at a small national liberal arts college, we demonstrate that participants who were asked to recall a person or event that has benefited them since graduating, pledged larger amounts (an increase of 92%) compared to the control group, although the probability of making a pledge was statistically no different. (shrink)