Mandatory Minimum Penalties: Their Effects on Crime, Sentencing Disparities, and Justice System Expenditures

3. Some Theoretical and conceptual issues

A principal aim of this review was to assess the utilitarian aspects of MMS; that is, the potential crime preventive benefits of such penalties. As indicated in Section 1., these benefits can arise through incapacitation, general or specific deterrence, denunciation, or education (i.e., raising awareness and sensitization). Since penalties already tend to exist in areas where MMS are introduced (e.g., murder, firearms-related crimes, impaired driving), demonstrating that a given MMS has an absolute deterrent or incapacitation effect is insufficient. Sentences for robbery, for example, had a potential preventive effect prior to the introduction of sentence enhancements (MMS in addition to the primary offence) for using a firearm in robberies and other offences. Thus, the marginal or additional benefit of MMS over previous penalties must be established (Shavell, 1992).

These marginal preventive effects, in turn, can exist only if MMS actually increase the certainty and/or severity of punishment. If their perceived severity results in fewer guilty pleas and more cases proceeding to trial, the certainty and celerity of their imposition may be diminished relative to sentences imposed previously. Also, MMS do not guarantee that sentence severity will increase, as sentences under a previous sentencing regime may have typically exceeded the minimum penalty introduced. These concerns underscore the necessity of examining the implementation of MMS, as marginal benefits cannot accrue if MMS are circumvented at the prosecutorial stage or fail to result in more certain and severe punishment. This review, therefore, devotes considerable attention to issues in the implementation of MMS.

Even where the marginal preventive effects of MMS are demonstrated, a further difficulty arises with regard to the explanation of these effects. If a “three strikes” law, such as that enacted in California, is accompanied by a sharp decline in felonies over a period of several years, to which utilitarian doctrine do we attribute this finding? It is difficult to distinguish whether the law has proven effective due to deterrence, incapacitation, moral condemnation/sensitization, or some combination of these factors. Few studies try to empirically determine the relative importance of these explanations. As a result, our focus here will be on the impact of MMS, rather than on explaining any effects observed.

An additional issue is that MMS apply to a wide range of sanctions internationally, from mandatory license restrictions and fines for impaired driving to mandatory life sentences and even the death penalty for certain categories of murder. Thus, sweeping statements about the utility of MMS are problematic. Sentences of varying degrees of severity ought to be considered separately. Accordingly, impaired driving, drug, and firearms offences are discussed in different sections of this report.