In this paper, we propose a decision framework where people are individually asked to either actively consent or dissent to some pro-social behavior. We hypothesize that confronting individuals with the choice of engaging in a specific pro-social behavior contributes to the formation of...

There is a longstanding concern that material rewards might undermine pro-social motivations, thereby leading to a decrease in blood donations. This paper provides an empirical test of how material rewards affect blood donations in a three-month large-scale field experiment and a fifteen-month...