Mens Rea and the Cost of Ignorance

Abstract

While the controversial doctrine of strict liability occupies an important place in modern criminal law, existing theories fail to explain when and why this doctrine is used instead of mens rea. This Essay advances a new understanding of strict criminal liability and explores its implications. The drawback of a mens rea standard is that it assures ignorant offenders that they can engage in the prohibited conduct without being penalized. This shortcoming, however, will be mitigated when offenders find that the market imposes too high a cost on ignorance. If ignorance is sufficiently costly, offenders will take steps to become (or remain) informed notwithstanding the adverse incentive created by the mens rea standard. The Essay thus predicts that, other things being equal, strict liability is likely to govern only those elements of a criminal offense for which ignorance is virtually costless. The Essay proceeds to demonstrate the illuminating power of this theory by analyzing the seemingly puzzling application of strict liability to liquor-sale to minors, statutory rape, child-pornography, regulatory offenses, criminal liability of corporate officers, and mistakes of law and fact. The Essay concludes by exploring whether alternative doctrines may induce offenders to acquire information without producing the harsh and unfair consequences often attributed to strict liability.