We conduct a field experiment to test the non-monotonic effect of deadline length on task completion. Participants are invited to complete an online survey in which a donation goes to charity. They are given either one week, one month or no deadline to respond. Responses are lowest for the one-month deadline and highest when no deadline is specified. No deadline and the one-week deadline feature a large number of early responses, while providing a one-month deadline appears to give people permission to procrastinate. If they are inattentive, they might forget to complete the task
