Economic analysis of criminal procedure: Mapping out the aftermath of the exclusionary rule

With its 1961 Mapp v. Ohio ruling, the U.S. Supreme Court declared that every state must exclude from criminal trials evidence obtained in violation of the Fourth Amendment. This doctrine is the exclusionary rule. At the time the Court issued its ruling, twenty-four states used ill-gotten evidence in their criminal trials. Despite the lack of substantial empirical investigation of the Court's ruling, a widespread myth declares that the exclusionary rule has no substantial impact on crime. This dissertation investigates the aftermath of the Court's controversial ruling, utilizing the rational choice economic model developed by Gary Becker and modern econometric techniques. The economic model of the search warrant process predicts an increase in crime rates after the Court forced states to adopt the exclusionary rule as police officers substitute away from searches towards alternatives they consider less effective. The empirical analysis supports the theoretical predictions, and dispels the myth of the exclusionary rule. A tremendous increase in crimes followed the Court's enactment of the exclusionary rule, ranging from 3 percent increases in larceny offenses to 30 percent increases in assault offenses. Analysis of suburb cities reveals that these cities bore the brunt of the aftermath of the Court's ruling. In addition to the Mapp v. Ohio ruling, the empirical analysis examines two other gigantic changes in criminal procedure imposed on the states by the Court: the Gideon v. Wainwright ruling of 1962, granting indigent defendants the right to counsel; and the Miranda v. Arizona ruling of 1966, granting the right to remain silent and have an attorney present during questioning. While not quite as spectacular as the aftermath of Mapp v. Ohio, these two rulings increased crime rates in those states upon which the Court dictated the new rules.