We study how to promote compliance with rules in everyday situations. We have access to data on the users of all public libraries in Barcelona, where, in contrast to other studies, compliance with rules can be observed perfectly. In this setting, we test the effect of sending email messages with different contents.
We find that users return their items earlier if asked to do so in a simple email, showing that a general reminder of the users’ duty is effective in promoting rule compliance. Furthermore, adding other contents to the general reminder does not increase compliance significantly.