Deployments, Combat Exposure, and Crime

During the period 2001–9, four combat brigades and the Third Armored Cavalry Regiment were based at Fort Carson, Colorado. These units were repeatedly deployed during the Iraq War, which allows us to measure the effect of arguably exogenous changes in troop levels on violent crime in El Paso County, where Fort Carson is located. We find that never-deployed units contributed to community violence in the form of assaults, murders, rapes, and robberies. In contrast, estimates of the relationship between previously deployed units and violent crime are generally small and statistically insignificant at conventional levels.

We interpret this pattern of results as evidence that never-deployed units represent a greater threat to public safety than units recently returned from combat.