law Definition, Systems, Institutions, & Fields It also forms the basis for the Law codes of most countries of continental Europe and has played an important role in the creation of the idea of a common European culture (Stein, Roman Law in European History, 2, 104–107). Competition law, known in the United States as antitrust law, is an evolving field that traces as far back as Roman decrees against price fixing and the English restraint of trade doctrine. Modern competition law derives from the U.S. anti-cartel and anti-monopoly statutes of the turn of the 20th century. It is used to…