The focus of the article is on developing an alternative, economically-informed approach to the reasonable expectation of privacy test. This model, which is contrasted to the “moral” approach to privacy, views privacy as a normatively neutral aspect of self-interest aimed at concealing and controlling potentially damaging personal information. This economically-informed view of privacy maintains that privacy should not be protected when its primary effect is to impede the optimal deterrence of crime. On the other hand, legal protections against governmental surveillance have the potential to enhance social welfare by diminishing the costs of nonlegal privacy barriers, encouraging productive transactions, and reducing suboptimal policing practices such as discriminatory profiling and the enforcement of inefficient criminal prohibitions. It is argued that economics and public choice theory can help minimize decisionmaking errors by predicting which legal actors--police, legislatures, or courts--are best suited to make optimal trade-offs between privacy and crime control. In making this argument, the author sets out to develop a fully instrumentalist approach to the reasonable expectation of privacy test, beginning with an economic analysis. The economic approach stands in stark contrast to the prevailing moral approach to privacy, which views privacy as a fundamental right. The author reviews the American and Canadian Supreme Courts’ reasonable expectation of privacy doctrines and highlights their main inadequacy: the indeterminacy of the “public exposure” and “intimacy” doctrines used by the Courts in their decisions on the regulation of novel search technologies. The economic approach is then applied to two novel search technologies: infrared imaging and location tracking. The final analysis suggests the courts should protect the reasonable expectation of privacy in the location tracking case but not in the infrared imaging case. Footnotes