The Incapacitative Effect of Imprisonment: Some Estimates

Recent research on the functions of imprisonment has begun to provide quantitative, empirical knowledge of its rehabilitative and deterrent effects. Much less is known, however, about the incapacitative effect of imprisonment. While it has long been understood that the physical segregation of prison inmates prevents them from engaging in some criminal activity (as well as much non-criminal activity) during the period of their confinement, quantitative estimates of the size of this effect have been lacking. Leaving aside all deterrent or rehabilitative and counter-rehabilitative effects, it is of some interest to know whether the incapacitative function of imprisonment is large or small.