Using administrative, longitudinal data on felony arrests in Florida, we exploit the
discontinuous increase in the punitiveness of criminal sanctions at 18 to estimate the
deterrence effect of incarceration. Our analysis suggests a 2 percent decline in the logodds
of offending at 18, with standard errors ruling out declines of II percent or more.
We interpret these magnitudes using a stochastic dynamic extension of Becker's (1968)
model of criminal behavior. Calibrating the model to match key empirical moments, we
conclude that deterrence elasticities with respect to sentence lengths are no more negative
than -0.13 for young offenders.