A technique is described for determining the optimal level of law enforcement. It entails identifying the physical and psychic harm inflicted by crime, the costs of apprehension and conviction, the costs of wrongful conviction and punishment, and the social cost of punishing criminals. The most important attribute of this technique is its basing law enforcement on subjective perceptions of the costs of crime and hence on willingness to pay for law enforcement. Public resources are shifted among different policies in accordance with public preferences. The explicit goal is to maximize social welfare or utility, with social welfare being understood as the summation of private interests or utilities. This welfare-economics approach to law enforcement is incompatible with the American system, because it overlooks the possible conflict between wisdom (in the form of good laws that reflect important moral values) and consent (in the form of public willingness to pay for law enforcement). By ignoring the formative effect of law on public character, the economist reduces the problem of law enforcement to a consideration of what the public will pay for. Thus, welfare economics fails to supply the moral or intellectual basis for leadership in policymaking. Footnotes with references are provided.