Does the Punishment Fit the Crime? Speeding Fines and Recidivism

We estimate the causal effect of harsher speeding punishments on future driving behavior of cited drivers. To account for the fact that punishments are not randomly assigned, we leverage variation in ticket-writing practices across highway patrol officers in Florida. The fine associated with a ticket written for 10-14 MPH over the speed limit is, on average, $75 higher than that with a ticket for 9 MPH over the limit. Over 30% of tickets are written for exactly 9 MPH above the limit, while less than 3% are written for 10 MPH over, suggesting that officers manipulate the ticketed speed, and by extension, the fine faced by the driver. Officers vary considerably in their propensity to write tickets for the lower fine amount, and we instrument the punishment faced by a ticketed driver with the stopping officer's average lenience towards other drivers. Our estimates suggest that, compared with those receiving a higher fine, drivers receiving the lenient fine are over 25% more likely to receive an additional speeding ticket in the following year. We also find that drivers receiving the lenient fine are about 14% more likely to be involved in a car accident in the following year, although this result is more sensitive