Active Decisions and Pro-social Behavior:A Field Experiment on Blood Donation

In this paper, we propose a decision framework where people are individuallyasked to either actively consent or dissent to some pro-social behavior. We hypothesize thatconfronting individuals with the choice of engaging in a specific pro-social behaviorcontributes to the formation of issue-specific altruistic preferences while simultaneouslyinvolving a commitment. The hypothesis is tested in a large-scale field experiment on blooddonation. We find that this "active-decision" intervention substantially increases the actualdonation behavior of people who have not fully formed preferences beforehand.