The complementary role of liability and safety regulation

This article deals with the control of hazardous activities in situations where potential victims can affect their exposure to risk. Economists have generally considered ex ante regulation (safety standards) to be a substitute for ex post policies (exposure to tort liability) in order to control externalities. We show that when the victim's compensation is partial (e.g., due to death or serious bodily injury) there are inefficiencies associated with the exclusive use of negligence liability and that an optimal policy may involve the combined use of ex-ante regulation and ex-post liability. A noteworthy feature of our explanation is that regulation is complementary to liability, in the sense that it may facilitate a higher and more efficient standard of negligence. In that case, it is efficient to set the regulatory safety standard below the standard of negligence, which is consistent with the legal doctrines of negligence per se and the (non) regulatory compliance defense.