The Effects of the Fourth Amendment: A Strategic Model of Crime and Search

2005

Abstract:
The Fourth Amendment requires police to have probable cause before searching people or their property in criminal investigations. In practice, it is enforced through the exclusionary rule: if police search without probable cause, any evidence found in the search may be excluded from court.

We analyze the effects of this rule on equilibrium elements of social welfare in a strategic model of crime and search. The rule always increases crime. But it has two opposing effects on police searches. It directly reduces them by reducing the chances that they lead to successful conviction, but it also indirectly increases them by increasing crime. If the indirect effect dominates, the rule actually increases searches, and has an ambiguous effect on wrongful searches. If the direct effect dominates, it reduces searches and wrongful searches.

In contrast, direct police accountability for wrongful searches unambiguously reduces searches and wrongful searches. ..The Rest of the Paper.. by HUGO M. MIALON, Emory University - Department of Economics -and- SUE H. MIALON, Emory University; University of North Dakota