Round Giving: A Field Experiment on Suggested Charitable Donation Amounts in Public Television
Direct-mail fundraisers commonly provide a set of suggested donation amounts to potential donors, in addition to a write-in option. We conducted field experiments on direct-mail solicitations to over 10,000 members of a public television station, varying the string of suggested amounts. Increasing the vector of suggested amounts by 20-40 percent statistically significantly reduced the overall probability of giving by 15 percent, with no impact on gift amount. However, lowering the second-highest suggested amount from $100 to $95 produced an effect in the opposite direction, significantly reducing the number of gifts above $90 by over 30%. Both manipulations (increasing the suggestion vector and using a non-round number) led to a larger proportion of write-in donations, even as they reduced the number of total gifts. In contrast to standard economic models of charitable giving, our results provide evidence that donors incur a cognitive cost from writing in an amount that differs from a suggested amount.
This paper previously circulated under the title "How do Suggested Donations Affect Charitable Gifts?"
First version: January 2015
Last revised: April 2017