Economics: Today and Tomorrow © 2012Chapter 9:
Competition and MonopoliesChapter OverviewsSection 1: Perfect Competition
Market structure refers to the extent of competition within a market. There are four basic market structures: perfect competition, monopolistic competition, oligopoly, and monopoly. Perfect competition means there are many buyers and sellers, and no single buyer or seller can affect price. Section 2: Monopoly, Oligopoly, Monopolistic Competition
Most industries represent some form of imperfect competition: monopoly, oligopoly, or monopolistic competition. A monopoly exists when a single seller controls the supply of a good or service and largely determines its price. There are three types of monopolies: natural, geographic, technological, and government. An oligopoly exists when an industry is dominated by a few suppliers that have some control over price. Monopolistic competition exists when many sellers offer similar products, and each firm has some control over price. Section 3: Government Policies Toward Competition
The aim of government regulation is to promote efficiency, competition, fairness, and safety. The goal of antitrust legislation is to encourage competition and prevent unfair trade practices. Most antitrust legislation deals with restricting harmful effects of mergers.  | 
