This article first parses the multiple overlapping definitions of discrimination, including distinctions between group and individual discrimination and between segregation and discrimination in pay. The article then summarizes the major economic models of discrimination, particularly Becker's taste-for-discrimination model and statistical-discrimination models, as well as sorting and status-production models. The discussion focuses on the conditions under which markets will tend to eliminate discrimination, noting that this occurs in a more limited range of situations than commonly recognized. The article next surveys the economic role of antidiscrimination laws, evaluating arguments that the law speeds the journey to a non-discriminatory equilibrium and that the law breaks social norms perpetuating inefficient discrimination. Finally, the article examines empirical studies of employment discrimination laws, including analyses of litigation trends and of the laws' effects on labor markets.