Forgetting and Heterogeneity in Task Delay: Evidence from New York City Parking-Ticket Recipients

We study response behavior of New York City parking-ticket recipients by analyzing administrative data on 6.6 million tickets issued to 2 million individuals over two years. Exploiting variation (from a policy change and a field experiment) in letters sent to recipients, we find that forgetting plays a major role in delay–letters seem to act mostly as reminders, with their content mattering little. Moreover, by studying an individual’s behavior across multiple tickets, we find significant heterogeneity in underlying types, with different types reacting differently to deadlines and reminders. Failure to account for this heterogeneity yields biased–and sometimes incorrect–conclusions.