Final version: 'An Economic Understanding of Search and Seizure Law'

The final version of my new article, "An Economic Understanding of Search and Seizure Law," has just been published by the University of Pennsylvania Law Review. Here's the abstract:

This Article uses economic concepts to understand search and seizure law, the law governing government investigations that is most often associated with the Fourth Amendment. It explains search and seizure law as a way to increase the efficiency of law enforcement by accounting for external costs of investigations. The police often discount negative externalities caused by their work. Search and seizure law responds by prohibiting investigative steps when external costs are excessive and not likely to be justified by corresponding public benefits. The result channels government resources into welfare-enhancing investigative paths instead of welfare-reducing steps that would occur absent legal regulation. This perspective on search and seizure law is descriptively helpful, it provides a useful analytical language to describe the role of different Fourth Amendment doctrines, and it facilitates fresh normative insights about recurring debates in Fourth Amendment law.

The idea of the article is that search and seizure law, most prominently the Fourth Amendment, can be understood as a way to lower the societal costs of enforcing criminal laws. Criminal laws do not enforce themselves. Someone needs to collect evidence to allow the government to prove cases beyond a reasonable doubt. In a world with no legal restrictions on search and seizure, the police would collect evidence even when its societal cost in civil liberties harms greatly outweighs its societal benefit that comes from successful prosecution of crime. Search and seizure law can step in and block investigative steps when that is likely to happen. When it works as it should, search and seizure law bans the societally harmful ways of collecting evidence and lets the police choose among societally beneficial ways of collecting evidence. This role can be somewhat hard to see in existing laws because search and seizure law usually works through categorical rules rather than case-by-case. But a close look at Fourth Amendment case law, the most prominent example of search and seizure law, shows how it can be understood as a way to lower the costs of police investigations.