Andrew von Hirsch

Abstract: A number of estimates of incapacitative effects from incarceration of convicted offenders are available. While these estimates vary in absolute magnitude, the studies consistently find that crime reduction achieved by existing collective incapacitation policies is modest, at under 20 percent of crimes prevented. Further crime reduction from alternative policies that would impose fairly stringent mandatory five-year prison terms after convictions for serious offenses is similarly modest. Implementing these alternative policies, however, would result in dramatic increases in already record-size prison populations. In view of the limited crime reduction and enormous increases in prison population associated with collective incapacitation policies, recent research has explored the potential benefits of more selective or targeted incapacitation. If a small number of high-rate offenders commit a disproportionately large amount of crime, targeting limited prison resources on these offenders should achieve increa...