Simultaneity complicates the estimation of the causal effect of police
on crime. We overcome this obstacle by focusing on a mass layoff of
Oregon State Police in February of 2003. Due solely to budget cuts,
35 percent of the roadway troopers were laid off, which dramatically
reduced citations. The subsequent decrease in enforcement is
associated with a significant increase in injuries and fatalities. The
effects are similar using control groups chosen either geographically
or through data-driven methods. Our estimates suggest that a highway
fatality can be prevented with $309,000 of expenditures on state
DeAngelo, Gregory, and Benjamin Hansen.
"Life and Death in the Fast Lane: Police Enforcement and Traffic Fatalities."
American Economic Journal: Economic Policy,
State and Local Government: Other Expenditure Categories
Illegal Behavior and the Enforcement of Law
Transportation: Demand, Supply, and Congestion; Safety and Accidents; Transportation Noise