Decarceration and crime: California's experience

We present a comprehensive evaluation of the effect on crime rates of California's decade of correctional reforms. Beginning in 2011, the state enacted several policy changes through both legislation as well as voter initiatives that greatly reduced prison and jail populations. We find little evidence of an impact on violent crime rates in the state. Once changes in offense definitions and reporting practices in key agencies are accounted for, violent crime in California is generally lower than the levels that existed in 2010 prior to a wave major reform to the state's criminal justice system. While our analysis of violent crime rates yields a few significant point estimates (a decrease in murder for one method and an increase in robbery for another), these findings are highly sensitivity to the method used to generate a counterfactual comparison path. We find more consistent evidence of an impact on property crime. For the earliest major reform, we detect an increase in auto theft. For a major ballot initiative passed in late 2014 (proposition 47) we detect on impact on larceny theft. The latter estimates are sensitive to the method used to generate the counterfactual, with more than half of the relative increase in property crime (and for some estimates considerably more) driven by a decline in the counterfactual crime rate rather than increases for California for several of the estimators that we employ. Despite these measured increases and similar to violent crime, California property crime rates remain at historically low levels.