Source: Howard Bodenhorn, National Bureau of Economic Research (NBER), NBER Working Paper No. w20837, January 2015
From the abstract:
Prison overcrowding is a perennial problem and several states are under court order to reduce crowding. The long-term solution to crowding has been more prisons. The short-term solution is early release. Early release programs can be effective when they balance the savings of reduced prison costs against the costs of recidivism by released convicts. This paper uses historical data to investigate how prison officials altered their early release policies in the face of prison crowding and rising real per prisoner detention costs. The empirical evidence is consistent with the hypothesis that prison officials make use of information about the risks of recidivism revealed at trial and during incarceration to make informed decisions about whom to release and when.