American politicians and businessmen have criticized the Antimonopoly Act, Japanese antitrust legislation, for allowing horizontal restraints on trade known as cartels. This paper compares and contrasts U.S. antitrust laws with regards to horizontal restrains on trade from that of Japan. A highlighted difference between U.S. and Japanese antitrust legislation is the use of exemptions. The Antimonopoly Act provides for more exemptions immunizing a cartel, such as exceptions for cartels formed during a depression or when the defendants have little market power, than does similar legislation in the U.S. To illustrate how the exemption for cartels in a depressed industry applies in Japan, a case study of the Japanese shipbuilding industry is examined.