It is generally thought that following up with donors to thank them for their contributions will increase the likelihood that they will give again in the future. Fundraising professionals believe this relationship-building strategy could increase future donation probability by as much as 80 percent.

But in a paper in the American Economic Journal: Applied Economics, authors Anya Samek and Chuck Longfield found that thank-you calls had no impact on donor retention.

Their results come from an experiment conducted in the United States with 67 public television stations that conduct on-air fundraising drives, involving roughly 500,000 individual donors and thank-you calls between 2011 and 2016. 

The authors randomly selected new donors to receive a thank-you call or not. Callers contacted donors in the treatment group five to seven months after their donation, addressing them by name and explaining the impact of their gift. Importantly, they did not request another donation. 

Figure 1 from their paper reports one of their main results.

Figure 1 from Samek and Longfield (2023)

The x-axis in the chart indicates the number of weeks since receiving a thank-you call. And the y-axis indicates the cumulative probability of donating over time, calculated as the proportion of the sample who donated again. 

The dashed blue line represents new donors who didn’t receive thank-you calls. This series shows that the probability of donating again increases rapidly during the first fifty weeks and then gradually levels off at around 40 percent. The solid red line represents new donors who did receive calls, and this series follows a nearly identical pattern, indicating that the calls had no effect on giving behavior.

Given the widespread use of thank-you calls in the nonprofit industry, the researchers’ findings suggest that their utility deserves more scrutiny.