More tickets, fewer accidents : how cash-strapped towns make for safer roads created by Michael D. Makowsky and Thomas Stratmann

Traffic accidents are one of the leading causes of injury and death in the United States. The role of traffic law enforcement in the reduction of accidents has been studied by relatively few papers and with mixed results that may be due to a simultaneity problem. Traffic law enforcement may reduce the number of accidents, but police are also likely to be stricter in accident-prone areas. We use municipal budgetary shortfalls as an instrumental variable to identify the effect of traffic citations on traffic safety and show that budgetary shortfalls lead to more frequent issuance of tickets to drivers. Using a panel of municipalities in Massachusetts, we show that increases in the numbers of tickets written reduce the number of motor vehicle accidents and accident-related injuries. The findings show that failure to control for endogeneity results in a significant underestimation of the positive effect of law enforcement on traffic safety