Hebrew University of Jerusalem - Department of Economics; Washington University in Saint Louis - Department of Economics
March 3, 2011
The traditional premise of criminal law is that criminals who are convicted of similar crimes under similar circumstances ought to be subject to identical sentences. This article provides an efficiency-based rationale for discriminatory sentencing, i.e., establishes circumstances under which identical crimes ought to be subject to differential sentencing. We also establish the relevance of this finding to the practices of sentencing and, in particular, to the Sentencing Guidelines. Most significantly, we establish that the model can explain why celebrities, leaders, or recidivists ought to be subject to harsher sanctions than others. Discriminatory sentencing is optimal when criminals confer positive externalities on each other. If a criminal A who imposes (non-reciprocal) large positive externalities on criminal B is punished sufficiently harshly, B would expect A not to commit the crime and, consequently, he would expect not to benefit from the positive externalities conferred on him by A. Given that B's expected benefits are lower than the sanctions sufficient to deter B are also lower than the ones imposed on A. The result can be easily extended to the case of reciprocal externalities. Assume that a criminal A imposes positive externalities on B and B imposes identical positive externalities on A. If A is subject to a sufficiently harsh sanction and B knows this, B would expect A not to perform the crime and herefore would expect not to benefit from the positive externalities otherwise conferred on B. Consequently, a more lenient sanction than the sanction imposed on A would be sufficient to deter B.