Quality & Quantity 32: 257–273, 1998.
© 1998 Kluwer Academic Publishers. Printed in the Netherlands.
Analyzing the Relationships between Individual
Criminal Behavior and the Severity and Probability
Department of Sociology, Stockholm University, S-106 91 Stockholm, Sweden
Abstract. This paper deals with problems encountered in analyzing how an individual is deterred
from committing a crime by the severity and probability of punishment. It is argued that it might be
advantageous to base such an analysis on a model of maximization of expected utility. According to
this model, the attractiveness of committing a crime is strongly affected by the product of the relative
utility of committing the crime and being punished as compared with the utility of not committing the
crime times the probability of the punishment. This implies that the bivariate linear relationships of
choices to commit or not to commit crime and the severity and probability factors are dependent on
the variations in both these factors and their mean values. In this paper, these bivariate relationships
are analyzed in two ways – formally-algebraically and by numerical examples.
How the severity and the probability of punishment deter individuals from commit-
ting crimes is a recurrent issue in criminological research. Much of the discussion
deals with the question of which, if either, of the two factors is more decisive –
a question whose answer has both theoretical and practical implications of great
importance. It seems to be a rather common view in the research that the prob-
ability factor is more decisive than the severity factor. This view has gained its
main support from non-experimental research showing that individual criminal
behavior is more strongly related to the probability of punishment, as perceived by
the individual, than to the perceived severity of punishment (for brief discussions,
see Piliavin et al., 1986; Gibbs, 1986: 111–113). The view has also been strength-
ened by ﬁndings concerning relationships at the societal level between crime and
measures of objective probability and objective severity (see, for example, Tittle,
1969; Gibbs, 1986: 110–111).
Findings about such societal relationships are, of course, very difﬁcult to use
in reaching conclusions about the deterrent effect of punishments at the individual
level (Gibbs, 1975: 148–149; Gibbs and Firebaugh, 1990). Interpreting the results
of non-experimental research on the relationship between individuals’ criminal
behavior and their perceptions of the probability and severity of punishment is