Libor Dušek and Christian Traxler

This paper studies how the swiftness of punishment – the delay from committing the offense to being punished – affects behavior. The context of our study is the enforcement of speeding tickets via automated speed cameras. Our data tracks the full driving history and the compliance with payment obligations of about 48,000 ticketed cars over almost 4 years. We exploit two sources of variation to estimate the effect of the delay in sending the speeding ticket on subsequent behavior: (1) quasi-experimental variation due to administrative backlogs and (2) truly experimental variation induced by randomizing the sending sequence of speeding tickets. Our key finding is that the swiftness of punishment has economically and statistically significant effects on payment compliance: sending a ticket within three weeks increases the probability that the ticket is paid by the prescribed deadline by 7.7-10.0 percent and the probability that the ticket is paid within one year by 5.5-7.7 percent, compared to sending a ticket after six or more weeks. Larger effects are observed for private car owners than for corporate car owners. We find no additional effects of a very short delay (sending the tickets within one week rather than two or three weeks) and find only limited evidence of an effect of swiftness on the speeding behavior.