Round Giving: A Field Experiment On Suggested Donation Amounts In Public‐Television Fundraising

Direct‐mail fundraisers commonly provide a set of suggested donation amounts to potential donors, in addition to a write‐in option. Standard economic models of charitable fundraising do not predict an impact of suggested amounts on charitable giving. However, our field experiments on direct‐mail solicitations to over 10,000 members of a public television station tell a different story. We find that changing one of the suggested amounts in an ask string from $100 to $95 reduces the number of gifts greater than or equal to $90 by more than 30%. This contrasts with our finding that in three independent comparisons, increasing the entire vector of suggested amounts by 20%–40% reduces the probability of giving by approximately 15%, with little effect on the average size of the gift. Both manipulations lead to a larger proportion of write‐in donations, even as they reduce the number of total gifts. We propose a simple behavioral theory to explain the data: many donors prefer to give round numbers, and donors incur a cognitive cost when choosing to give a nonsuggested amount. (JEL C9, H4)