Deterrence in the Twenty-First Century

The evidence in support of the deterrent effect of the certainty of punishment is far more consistent than that for the severity of punishment. However, the evidence in support of certainty’s effect pertains almost exclusively to apprehension probability. Consequently, the more precise statement is that certainty of apprehension, not the severity of the ensuing legal consequence, is the more effective deterrent. This conclusion has important policy implications among which are that lengthy prison sentences and mandatory minimum sentencing cannot be justified on deterrence. There are four major research gaps. The first concerns the mechanism by which police affect perceptions of the probability of apprehension.…