Punitive Police? Agency Costs, Law Enforcement, and Criminal Procedure

Criminal law enforcement depends on public agents such as police officers, but the resulting agency problems are generally neglected. We develop an agency model of police behavior that emphasizes intrinsic motivation and self-selection. Drawing on experimental evidence on heterogeneous preferences for punishment, our model identifies circumstances in which punitive individuals (with stronger-than-average punishment preferences) self-select into law enforcement jobs that offer the opportunity to punish, or facilitate the punishment of, wrongdoers. Punitive agents accept a lower salary but create agency costs associated with excessive zeal in searching, seizing, and punishing suspects. In our framework, the public may choose to hire punitive police agents while providing suspects with criminal procedure protections, thereby empowering other agents (judges and juries) with average punishment preferences to limit the agency costs of excessive zeal. Intrinsic motivation and self-selection provide an explanation for the bifurcated structure of criminal law enforcement and pro-defendant rules of criminal procedure.