Economic theory has invaded legal scholarship and law schools, in the form of "Law and economics." But the psychology of judgments and decisions has invaded economic theory, showing that people do not follow the classic model of economic rationality. Many legal scholars, such as Cass Sunstein, claim to have started a new field called "Behavioral law and economics," which explores the implications of psychology for legal theory. This seminar will review basic readings in law and economics and then the recent literature on the relevance of psychology. Topics include risk regulation, liability, and regulation of political behavior.