We use quasi-random variation in the fraction of time served in the Italian “open-cell prison” of Bollate to estimate the effect of humane prison conditions on recidivism. We deal with the endogenous assignment of inmates to prison conditions by focusing on those inmates who are displaced to Bollate due to overcrowding in nearby prisons. The time of transfer is based on a FIFO, mechanical rule that is conditionally independent on any observable predictor of recidivism and is also unlikely to be related to any unobservable one. Spending one more year in the open prison (and one less year in an ordinary one) reduces recidivism by around 10 percentage points. While we find evidence that over time Bollate inmates become more likely to work outside the prison, more than a single mechanism underlies these effects.

Keywords: Crime, Prison Conditions, Rehabilitation
JEL Codes: K140, K420