Replication Data and Code for: "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 non-profit 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\%. In stark contrast, we found a precisely estimated null effect of calls on donor retention.