Another form of economic regulation, antitrust law, seeks to strengthen market forces so that direct regulation is unnecessary. The government -- and, sometimes, private parties -- have used antitrust law to prohibit practices or mergers that would unduly limit competition. Government also exercises control over private companies to achieve social goals, such as protecting the public's health and safety or maintaining a clean and healthy environment. The U.S. Food and Drug Administration bans harmful drugs, for example; the Occupational Safety and Health Administration protects workers from hazards they may encounter in their jobs; and the Environmental Protection Agency seeks to control water and air pollution. American attitudes about regulation changed substantially during the final three decades of the 20th century. Beginning in the 1970s, policy-makers grew increasingly concerned that economic regulation protected inefficient companies at the expense of consumers in industries such as airlines and trucking. At the same time, technological changes spawned new competitors in some industries, such as telecommunications, that once were considered natural monopolies. Both developments led to a succession of laws easing regulation. While leaders of both political parties generally favored economic deregulation during the 1970s, 1980s, and 1990s, there was less agreement concerning regulations designed to achieve social goals. Social regulation had assumed growing importance in the years following the Depression and World War II, and again in the 1960s and 1970s. But during the presidency of Ronald Reagan in the 1980s, the government relaxed rules to protect workers, consumers, and the environment, arguing that regulation interfered with free enterprise, increased the 12