Estimating the Deterrent Effect of Incarceration Using Sentencing Enhancements

Abstract:     
Increasing criminal sanctions may reduce crime through two primary mechanisms: deterrence and incapacitation. Disentangling their effects is crucial, since each mechanism has different implications for optimal policy setting. I use the introduction of state add-on gun laws, which enhance sentences for defendants possessing a firearm during the commission of a felony, to isolate the deterrent effect of incarceration. Defendants subject to add-ons would be incarcerated in the absence of the law change, so any short-term impact on crime can be attributed solely to deterrence. Using cross-state variation in the timing of law passage dates, I find that the average add-on gun law results in a roughly 5 percent decline in gun robberies within the first three years. This result is robust to a number of specification tests and does not appear to be associated with large spillovers to other types of crime.

Number of Pages in PDF File: 57

Keywords: Punishment, mandatory minimum sentencing, incarceration, sentence length, enhancement, armed robbery, use of a gun in the commission of a crime, general deterrence, empirical research, forecasting and simulation, ascertaining disparities in criminal behavior, add-ons, add-on gun laws

JEL Classification: C79, J24, K14, K42

working papers series