Economists since Pigou have advocated the use of economic incentives for controlling environmental degradation. In a similar vein, environmental economists have long lamented a near unanimous reliance of environmental policy on the use of direct regulation. However, several pieces of legislation, as well as common law doctrine, provide strict liability for damages from a variety of pollution incidents. The term strict liability means that a polluter is liable for the penalty imposed for a pollution incident irrespective of intent, fault, or even knowledge of the pollution incident. Negligence need not be proved, thus strict liability allows for no defense of due care or conformance with common practice.