Do Thank-You Calls Increase Charitable Giving? Expert Forecasts and Field Experimental Evidence

Calling to thank donors is considered a key fundraising strategy in the charitable giving industry. Yet the effectiveness of thank-you calls remains untested. We conduct field experiments with public television stations and a national nonprofit in which 500,000 new donors were randomized to receive a thank-you call or not. Fundraising professionals predicted that the calls—which followed standard practices in the industry—would increase donor retention by 80 percent. In stark contrast, we found a precisely estimated null effect of calls on donor retention. (JEL C83, C93, D64, D91, L31, L82)