Promoting rule compliance in daily-life: Evidence from a randomized field experiment in the public libraries of Barcelona

We study how to promote compliance with rules in everyday situations. Having access to unique data on the universe of users of all public libraries in Barcelona, we test the effect of sending email messages with dierent contents. We find that users return their items earlier if asked to do so in a simple email. Emails reminding users of the penalties associated with late returns are more effective than emails with only a generic reminder. We find differential treatment effects by user types. The characteristics we analyze are previous compliance, gender, age, and nationality.