Publication Type: Conference Paper/Unpublished ManuscriptAbstract: With reference to the classic modelling of criminal behaviour in Rational Choice Theory (e.g. Becker 1968), this paper presents an extended Subjective Expected Utility model for the explanation of criminality that is more in line with the requirements of theorizing and empirical testing than former approaches. In our model, the decision of an actor is influenced by the expected utility of the crime and the norms which prohibit the delinquent action. It is also suggested that there is an inter-action between utility and norms which reflect different pattern of decision making that lead to different probabilities for the occurrence of crimes. The relevance of the model is shown by using survey data from Germany. By applying a new technique to uncover interaction effects in nonlinear models, different decision pattern are revealed. On the one hand, it is likely that norms restrict criminal behaviour by sup-pressing cost-benefit calculations. On the other hand, it is also possible that the influence of norms is absorbed by cost-benefit calculations.