Thank You, Now What? How Donors Respond to Calls to Action

We study whether thank-you communications charities send to past donors should include a call to action (CTA), a direct request to give again, and show that the answer depends on whether the donor has already given in the current giving cycle. Although CTAs can clarify desired behavior and increase compliance, they may backfire when the request asks for giving beyond a donor’s typical cadence and violates expectations about when requests are appropriate. In a field experiment with 35,077 prior donors to a major Indian charity, we compare thank-you letters that include a CTA with otherwise identical letters without one. Response rates are low, as is typical in direct mail, with 0.69% of recipients giving. The CTA x recency interaction is statistically significant for donation amounts. Among donors who have not yet given in the current cycle, the CTA significantly increases giving, whereas among donors who have already given, point estimates indicate lower giving. The CTA helps one segment but is associated with lower giving in the other, so aggregate evaluations mask this heterogeneity. The results suggest that a donor’s giving status within the current cycle, a simple observable characteristic, can improve the targeting of fundraising communications and meaningfully affect revenue.