This paper estimates the impact of police presence on car accidents using a unique data- base that tracks the exact location of Dallas Police Department patrol cars throughout 2009. To address the concern that officer location can be a result of car accidents that have already occurred, my instrument exploits police responses to calls outside of their allocated coverage beat. This variable provides a plausible shift in police presence within the abandoned beat that is driven by the police goal of minimizing response times. I find that a 10 percent decrease in police presence at that location results in a 2.1 to 3.5 percent increase in car accidents. I show that this effect is likely driven by a decrease in traffic citations, highlighting the potential drawbacks of the rapid response policing strategy. (Author/publisher)
Abstract