rule of reason

Under "rule of reason" test for determining whether alleged acts violated No. 1 of the Sherman Anti-Trust Act [15 U.S.C.A. No. 1], which declares conspiracies in restraint of trade to be illegal, fact finder must weigh all circumstances of the case to decide whether practice unreasonably restrains competition, and the test requires that plaintiff show anticompetitive effects, or actual harm to competition, and not whether the practices were unfair or tortious. Richard Hoffman Corp. v. Integrated Bldg. Systems, D.C.I11., 610 F.Supp. 19, 22.

Under the "rule of reason" in antitrust law the legality of restraints on trade is determined by weighing all the factors of the case such as the history of the restraint, the evil believed to exist, the reason for adopting the particular remedy and the purpose or end sought to be attained. U. S. v. National Soc. of Professional Engineers, D.C.D.C., 404 F.Supp. 457, 463.

To constitute a crime under No. 1 of the Sherman Antitrust Act, the defendant's conduct must result in an unreasonable restraint of interstate commerce. It is for the jury to determine from a consideration of all the facts and circumstances, including the economic conditions of the industry and the effect on competition, whether defendants' conduct creates an unreasonable restraint on interstate commerce. Standard Oil Co. v. United States, 221 U.S. 1, 31 S.Ct. 502, 55 L.Ed. 619; Best Advertising Corp. v. Illinois Bell Tel. Co., C.A.I11., 339 F.2d 1009; Walker Process Equipment, Inc. v. Food Machinery & Chemical Corp., 382 U.S. 172, 86 S.Ct. 347, 15 L.Ed.2d 247.

The "rule of reason" test is not however applied in instances of per se antitrust violations; e.g. price-fixing

Compare per se doctrine

- per se violations