ABSTRACT
Evidence in support of the deterrent effect of various measures of the certainty of punishment is far more convincing and consistent than for the severity of punishment. However, the certainty of punishment is conceptually and mathematically the product of a series of conditional probabilities—the probability of apprehension given commission of a crime, the probability of prosecution given apprehension, the probability of conviction given prosecution, and the probability of sanction given conviction. The evidence in support of certainty’s deterrent effect pertains almost exclusively to apprehension probability. Consequently, the conclusion that certainty not severity is the more effective deterrent is more precisely stated as certainty of apprehension and not the severity of the legal consequence ensuing from apprehension is the more effective deterrent.
