Criminal Law and Behavioral Law and Economics: Observations on the Neglected Role of Uncertainty in Deterring Crime

Abstract

Two similarly situated individuals commit identical crimes. The first is sentenced to ten years in prison while the second is sentenced to five years. The disparity between the sentences of the criminals is a reason for concern. In contrast, two individuals commit identical crimes. When the first criminal commits the crime, the police invest few resources in detecting crimes of this sort. Consequently, the probability that the criminal will be detected is merely ten percent. When the second criminal commits the crime, the police conduct a major campaign and consequently the probability of detection is twenty percent. The latter case although creating disparate treatment does not raise the same type of moral resentment raised by the first. The moral concern of the person who asks "why me?" is compelling when there is a disparity in the sentences, but has no moral force when there is disparity in the probability of detection.

Various doctrines and practices illustrate the difference in the way uncertainty is treated in these contexts. Sentences are public; they constitute part of our criminal law. But no criminal code provides information with respect to the probability of detection, or conviction. Moreover, a criminal sanction cannot be imposed retroactively. On the other hand, a person who committed a crime while the probability of detection was low cannot complain that she was caught simply because the probability of detection increased after she had committed the crime. Last, the probability of detection often changes due to temporary enforcement campaigns. No analogous "sentencing campaigns" during which judges impose particularly heavy sanctions exist in the legal system. In sum, criminal sanctions are public, relatively stable and predictable. In contrast, the practices governing the determination of the probability of detection or conviction reinforce uncertainty.

The paper provides an efficiency-based explanation for the different treatments of certainty in these two contexts. The criminal law system aims at providing maximum deterrence at minimal costs. Since the cost of sentencing depends on the average sanction, the first question to answer is what is worse from the potential criminal's point of view: a sentencing scheme which guarantees certainty with respect to the sanction or a sentencing scheme which does not guarantee such a certainty. Similarly, in the context of detection and conviction, one should find out what is worse from the potential criminal?s point of view: a scheme which guarantees certainty with respect to the probability of detection and conviction, or one which does not guarantee such a certainty. Once we discover which scheme is worse for the criminal, the state should adopt this scheme since it has larger deterrent effects. In order to increase deterrence, the state should always adopt the scheme which is least desirable from the perspective of the potential criminal.

Our paper invokes insights from psychological experiments to examine the attitudes of criminals towards uncertainty and illustrates that criminals are likely to prefer a scheme in which the size of the sentence is uncertain while the probability of detection and conviction is certain. Consequently, the choice to increase certainty with respect to the size of the sentence and to decrease certainty with respect to the probability of detection and conviction can ultimately be justified on efficiency-based grounds.