A collection of different laws and court rulings that have evolved over time to govern the anti-competitive behavior of large business. Some of the business practices that may be illegal are agreements among competing businesses, such as agreements on price or related matters; agreements to restrict output; group boycotts, which drive up prices; and agreements among competitors to divide sales territories or allocate customers.

The Sherman Antitrust Act of 1890 prohibits contracts, conspiracies, and combina-
tions that would restrain trade or create a monopoly. The Act provides criminal penalties as an enforcement tool.

The Clayton Antitrust Act of 1914 outlaws exclusive dealing arrangements, tie-in sales, price discrimination, and mergers that would restrain trade and interlocking directorates. It carries only civil penalties and is enforced by both the Department of Justice and the Federal Trade Commission. The Clayton Act was significantly amended in 1936 by the Robinson-Patman Act and in 1950 by the Celler-Kefauver Antimerger Act.

The Federal Trade Commission Act was passed in 1914. It created a governmental agency whose responsibility is to protect consumers against illegal business practices and may catch loopholes in the other statutes.

The antitrust laws are enforced by the Federal Trade Commission and the Antitrust Division of the U.S. Department of Justice.