Zarghamee et al. (2017) on Nudging Charitable Giving

Homa S. Zarghamee, Kent D. Messer, Jacob R. Fooks, William D. Schulze, Shang Wu, and Jubo Yan, “Nudging Charitable Giving: Three Field Experiments.” Journal of Behavioral and Experimental Economics 66: 137- 149, February 2017 [abstract here].

• Study 1: Students had earned money over the duration of the semester by taking part in experiments; this study asked them if they wanted to donate some or all of their earnings to charity. 

• Envelopes were provided such that students could either donate some of their earnings (opting in to charity, n=69), or, request a refund from the contribution of their money (opting out of charity, n=118). 

• The opt-out version increases contributions by some 25%. 

• Study 2 (n at most 59) looks at whether some cheap talk and a vote prior to deciding to contribute to charity – and potentially to keep donating for 10 months – can induce more giving than without the chitchat and vote. The cheap talk does the (cheap) trick, inducing higher donations by some 47%.

• Study 3 (n=70) involves one treatment where the charity mentions HIV, whereas the other treatment does not. The treatment makes no difference to donations, but changes to positive and negative affect during the experiment do influence giving. A lower positive affect decreases giving, but an increase in negative affect increases giving.