Classic takes on the norm of reciprocity find that receipt of a gift increases compliance with a later request. We find that giving people the opportunity to return this gift surprisingly increases compliance rates, a phenomenon we call “returnable reciprocity”. Across four studies (N = 3,786), we find evidence that returnable reciprocity leads to greater compliance in a large-scale field experiment (Study 1), as well as in conceptual lab replications (Studies 2 and 3) involving different domains. We provide evidence that this increased compliance may be due to increased feelings of guilt for non-compliance (Study 3). Finally, we find that while the economic cost of returnable reciprocity is negligible, it may create additional psychological or societal costs that must be taken into account when assessing its social welfare implications (Study 4). We end by discussing the theoretical, practical and social welfare implications of this novel compliance strategy.
Zlatev, Julian J., and Todd Rogers. "Returnable Reciprocity: When Optional Gifts Increase Compliance." HKS Faculty Research Working Paper Series RWP20-007, March 2020.