经济学原理·萨缪尔森--中山大学岭南学院ch(8).ppt

,CH.10 Oligopoly and Monopolistic Competition,A. Behavior of Imperfect Competitors,Market Power: The degree of control that a single firm or a small number of firms has over the price and production decisions in an industry.,Four-Firm Concentration Ratio,The most common measure of market power is the four-firm concentration. Four-firm concentration: the percent of total industry output produced by the largest four firms.,the Nature of Imperfect Competition,Costs(成本) barriers（进入壁垒） strategic interaction（策略互动): Strategic interaction is a term that describes how each firms business strategy depends on their rivals strategies,Theories of Imperfect Competition,Firms operate in a cooperative mode when they try to minimize competition by agreeing explicitly or tacitly on price and output and other market issues. collusive oligopoly cooperativecollusion（共谋）,Cartel(卡特尔) When oligopolists would be delighted to earn profits, taking into account their mutual inter-dependence, they will produce the monopoly output and price and earn the monopoly profit.,Collusive Oligopoly Looks Much Like Monopoly,The Antitrust Laws,After the American public rose up and demanded the passage of tough antitrust laws in 1910, cartels and explicit collusion became illegal in the United States.,Some obstacles hinder effective collusion,Collusion is illegal. The member of Cartel may “cheat”. The competition from foreign firms.,Monopolistic Competition,Compare with perfect competition: Similarities: there are many buyers and sellers; entry and exit are ease; firms take other firms prices as given.,Distinction: products are differentiated under monopolistic competition.,Monopolistic Competitors Produce Many Similar Goods,Monopolistic Competition,Product differentiation leads to a downward slope in each sellers demand curve . The decision of production: MR=MC,Free Entry of Numerous Monopolistic Competitors Wipes Out Profit,Long run equilibrium,Free entry of numerous monopolistic competitors wipes out profit. In the Long run equilibrium for monopolistic competition, prices are above marginal costs but economic profits have been driven down to zero.,Reasonableness of existing monopolistic competition,Increase the diversity of available goods and services.,Rivalry among the few,Duopoly(双头垄断) Competition among the few forces firms to take into account competitors reaction to price and output deviations and brings strategic considerations into their markets.,Game Theory,In this realm, we are better able to capture the full diversity as well as the ambiguity of strategic behavior in oligopolistic situations.,Price discrimination,B. Innovation and Information,Two crucial features of imperfect competition: Divorce of ownership and control in the large corporation Information, Innovation and Schumpeterian Economics,Divorce of ownership and control,Three important potential conflicts of interest between managers and stockholders. Insider Dividends Risk and change,rationality and rules of thumb,rules of thumb: 凭经验的方法，简单决策原则。 bounded rationality有限理性 markup pricing（cost-plus-markup）成本加成,Information, Innovation, and Schumpeterian Economics,Schumpeter熊彼特 Economics of Information Intellectual property rights The dilemma of the internet The Schumpeterian hypothesis,C. A balance sheet of imperfect competition,Economic Costs of Imperfect Compe