Additive Effects of Certainty,Severity, and Celerity of Punishment on Judgments of Crime Deterrence Scale Value1

The certainty and severity of punishment for crimes are commonly given credence as determinants of deterrence value, whereas celerity of punishment is not. Moreover, data are sparse and divided on the question of how certainty and severity components combine algebraically. Two experiments inspected the effects of certainty, severity and celerity of hypothetical punishments on judged deterrence value, and the form of their factorial combination. Judged deterrence scale values were obtained for eight hypothetical conditions of punishment for serious crimes. These conditions of punishment consisted of orthogonal combinations of two levels each of certainty, severity, and celerity and were administered to independent subjects. Strong effects of certainty and severity and moderate effects of celerity were found, and there were no interactions among the three variables. Thus, celerity is pertinent to judged deterrence value, and the three components of punishment clearly combine additively rather than multiplicatively. It is argued that despite the empirical results, certainty, severity, and celerity must, however, ultimately be showp to combine according to a multiplying rule. The Discussion centers largely on an analysis and justification for that argument.