HO5e-Ch14---Microeconomics

1、R. GLENNHUBBARD,ANTHONY PATRICKOBRIEN,FIFTH EDITION, 2015 Pearson Education, Inc.,Oligopoly:Firms in Less Competitive Markets,Oligopoly: A Very Different Market Structure,In the previous chapters, we examined perfect and monopolistic competition. We were able to use similar logic to argue how those

2、firms would behave: they would produce until their marginal cost was equal to marginal revenue, and the low barriers to entry would result in profit being competed away in the long run. Oligopoly, a market structure in which a small number of interdependent firms compete, will require completely dif

3、ferent tools to analyze. Why? Oligopolists are large, and know that their actions have an effect on one another. Barriers to entry exist, preventing firms from competing away profits.,Oligopoly and Barriers to Entry,14.1,Show how barriers to entry explain the existence of oligopolies.,Which Markets

4、Are Oligopolistic?,Before we analyze how oligopolists behave, it is useful to know which firms/markets we are discussing. A useful tool for identifying the type of market structure is the four-firm concentration ratio: the fraction of an industrys sales accounted for by its four largest firms. A fou

5、r-firm concentration ratio larger than 40% tends to indicate an oligopoly. Although there are limits to how useful four-firm concentration ratios can be, they are a useful tool in discussing the concentration of market power within an industry.,Examples of Oligopolies,Examples of oligopolies in reta

6、il trade and manufacturing,Table 14.1,Why Do Oligopolies Exist?,Oligopolies often exist because of barriers to entry: anything that keeps new firms from entering an industry in which firms are earning economic profits. One example of a barrier to entry is economies of scale: the situation when a fir

7、ms long-run average costs fall as the firm increases output. This can make it difficult for new firms to enter a market, because new firms usually have to start small, and will hence have substantially higher average costs than established firms.,Economies of Scale and the Extent of Competition,An i

8、ndustry will be competitive if the minimum point on the typical firms long-run average cost curve (LRAC1) occurs at a level of output that is a small fraction of total industry sales, such as Q1. The industry will be an oligopoly if the minimum point comes at a level of output that is a large fracti

9、on of industry sales, such as Q2.,Economies of scale help determine the extent of competition in an industry,Figure 14.1,Why Else Do Oligopolies Exist?,Ownership of a key input If control of a key input is held by one or a small number of firms, it will be difficult for additional firms to enter. Ex

10、amples: Alcoabauxite for aluminum productionDe BeersdiamondsOcean Spraycranberries Government-imposed barriers Governments might grant exclusive rights to some industry to one or a small number of firms. Examples:Occupational licensing for dentists and doctorsPatentsTariffs and quotas imposed on for

11、eign companies Patent: The exclusive right to a product for a period of 20 years from the date the patent is filed with the government.,Using Game Theory to Analyze Oligopoly,14.2,Use game theory to analyze the strategies of oligopolistic firms.,Why Do We Need a Special Theory for Oligopoly?,Perfect

12、 and monopolistic competitors were easily analyzed using a graph of their own costs and revenues. But remember that each of these firms were small relative to the market, so their actions were essentially insignificant to other firms. This is not true for oligopolies. Oligopolists are large relative

13、 to the market, and the actions of one oligopolist make large differences in the profits of another. Oligopolies are best analyzed using a specialized field of study called game theory. Game theory: The study of how people make decisions in situations in which attaining their goals depends on their

14、interactions with others; in economics, the study of the decisions of firms in industries where the profits of a firm depend on its interactions with other firms.,Game Theory,Game theory was developed during the 1940s and advanced by mathematicians and social scientists like economists. All “games”

15、share certain characteristics: Rules that determine what actions are allowable Strategies that players employ to attain their objectives in the game Payoffs that are the results of the interactions among the players strategies For example, we can model firm production as a “game”: Rules: the product

16、ion functions and market demand curve Strategies: Firms production decisions Payoffs: Firms profits,A Duopoly Game: Price Competition Between Two Firms,In this payoff matrix, Sonys profits are in blue, and Microsofts profits are in red. Sony and Microsoft would each make profits of $10 million per m

17、onth on sales of video game consoles if they both charged $499.,If one charges $499 and the other charges $399, the one with a low price earns $15 million per month, while the other earns only $5 million per month. If both firms charge $399, they would each make a profit of only $7.5 million per mon

18、th. How would you “play” this duopoly game? Duopoly: An oligopoly with two firms,A duopoly game,Figure 14.2,A Dominant Strategy for Sony,Suppose you are Sony in this duopoly game. If Microsoft charges $499, you earn more profit by charging $399. If Microsoft charges $399, you earn more profit by cha

19、rging $399.,Either way, charging $399 seems makes the most profit. It is a dominant strategy for Sony. Dominant strategy: A strategy that is the best for a firm, no matter what strategies other firms use.,A duopoly game,Figure 14.2,A Dominant Strategy for Microsoft Also,Now suppose you are Microsoft

20、: If Sony charges $499, you earn more profit by charging $399. If Sony charges $399, you earn more profit by charging $399.,Either way, charging $399 seems makes the most profit. It is a dominant strategy for Microsoft to charge $399 also! Each firm charging $399 is a Nash equilibrium: a situation i

21、n which each firm chooses the best strategy, given the strategies chosen by the other firms.,A duopoly game,Figure 14.2,Could the Firms Do Better?,Notice that this outcome is not good for Sony or Microsoft; if they could cooperate somehow, they could each earn more profit.,This is the benefit of col

22、lusion: an agreement among firms to charge the same price or otherwise not to compete. Collusion is against the law in the United States, but you can see why firms might be tempted to collude: their profits could be substantially higher.,A duopoly game,Figure 14.2,Prisoners Dilemma,Economists and ot

23、her social scientists refer the situation with Sony and Microsoft as a prisoners dilemma: a game in which pursuing dominant strategies results in noncooperation that leaves everyone worse off. The name comes from a problem faced by two suspects the police arrest for a crime. The police offer each su

24、spect a suspended prison sentence in exchange for confessing to the crime and testifying against the other suspect. Each suspect has a dominant strategy to confess; but if both confess, they both go to jail for a long time, while they both could have gone to jail for a minimal length if they had bot

25、h remained silent.,Is There a Dominant Strategy for Bidding on eBay?,Standard eBay auctions function as second-price auctions: the high bidder wins the item, and pays the price bid by the second-highest bidder. An intuitive strategy for bidding on eBay is to shade your bid: bidding somewhat less tha

26、n your valuation.,But this intuition is incorrect. In fact, eBay bidders have a dominant strategy: bid exactly how much they value the object. How can this be?,A Dominant Strategy for Bidding on eBay,Suppose you are bidding on a concert ticket worth $200 to you. If you bid less than $200, then eithe

27、r: You winbut you pay the same as if you had bid $200, so there was no advantage to bidding less; or,You lose; if someone bids more than $200, then you would have lost anyway. But if the winning bid was less than $200, you will wish you had bid $200. Similar logic applies if you bid more than $200.

28、Bidding $200 is a dominant strategy!,Can Firms Escape the Prisoners Dilemma?,Suppose Dominos and Pizza Hut are deciding how to price a pizza: $12 or $10. This game gets played not once, but every day. A clever way to avoid the low-profit Nash equilibrium is to advertise a price-match guarantee. Then

29、 if either firm cuts prices, the other has guaranteed to do so as well. Now neither firm will have an incentive to cut prices. Price-match guarantees arent as good for consumers as they appear.,Changing the payoff matrix in a repeated game,Figure 14.3,Other Methods for Avoiding Price Competition,A p

30、rice-match guarantee is an enforcement mechanism, making automatic the decision about whether to punish a competing firm for charging a low price. Another method is price leadership, a form of implicit collusion in which one firm in an oligopoly announces a price change and the other firms in the in

31、dustry match the change. Example: In the 1970s, General Motors would announce a price change at the beginning of a model year, and Ford and Chrysler would match GMs price change. Such forms of implicit collusion are desirable for firms, because explicit collusion is illegal, resulting in government

32、fines and penalties, along with a possible public backlash.,With Price Collusion, More Is Not Merrier,Airlines are a good example of an oligopoly. Airlines often implicitly collude, having unspoken understandings with one another not to compete on price. If one airline cuts prices, the others will r

33、etaliate, decreasing industry profits for all (since airline travel is relatively price-inelastic).,Thus, the same route is often identically priced by several different airlines. Implicit understandings like this are easier to enforce with fewer competitors, which helps to explain why price competi

34、tion often results when new firms enter a market.,Cartels: The Case of OPEC,A cartel is a group of firms that collude by agreeing to restrict output to increase prices and profits. This form of explicit collusion is illegal in the United States; but not in some other locations.,The most well-known c

35、artel is OPEC, the Organization of the Petroleum Exporting Countries. OPEC members colluded to restrict output and raise prices in the 1970s and 1980s. But collusion has proved difficult to maintain over time.,Oil prices, 1972 to mid-2013,Figure 14.4,Analyzing the OPEC Cartel with Game Theory,Becaus

36、e Saudi Arabia can produce much more oil than Nigeria, its output decisions have a much larger effect on the price of oil. Saudi Arabia has a dominant strategy to cooperate and produce a low output.,Nigeria, however, has a dominant strategy not to cooperate and instead produce a high output. In orde

37、r to punish Nigeria for defecting, Saudi Arabia would have to hurt itself substantially. Would it be worth it to you?,The OPEC cartel with unequal members,Figure 14.5,Sequential Games and Business Strategy,14.3,Use sequential games to analyze business strategies.,Simultaneous vs. Sequential Games,Th

38、e game theory models we have analyzed so far have been simultaneous: the players have made their decisions at the same time. But some games are sequential in nature: one firm makes a decision, and the other makes its decision having observed the first firms decision. We analyze such games using a de

39、cision tree, indicating who gets to make a decision at what point, and what the consequences of their decision will be.,The Decision Tree for an Entry Game,In this game, Apple decides whether to charge $1000 or $800 for its new ultra light laptop; then Dell decides whether or not to enter the market

40、.,Apple “looks ahead”, and realizes that if it charges the high price, Dell will enter and compete with Apple. If Apple charges the low price, Dells rate of return will not be sufficient to warrant entry. So Apple can deter Dell from entering the market by preemptively charging the low price.,The de

41、cision tree for an entry game,Figure 14.6,The Decision Tree for a Bargaining Game,Dell is deciding whether to offer $20 or $30 per copy for TruImages software. Then TruImage will have the opportunity to accept or reject the offer.,Dell will look ahead, and realize that TruImage is better off accepti

42、ng Dells offer, no matter what price Dell offers. Therefore Dell should offer the low price, anticipating that TruImage will accept the offer.,The decision tree for a bargaining game,Figure 14.7,Can TruImage Threaten Not to Accept the Offer?,Notice that TruImage would like to threaten to reject an o

43、ffer of $20. If Dell believed the threat, its best action would be to offer $30.,But Dell shouldnt believe the threat; it is not credible, since it would involve TruImage hurting itself with no opportunity for redemption. Only the original outcome is a subgame-perfect equilibrium: a Nash equilibrium

44、 in which no player can improve their outcome by changing their decision at any decision node.,The decision tree for a bargaining game,Figure 14.7,The Five Competitive Forces Model,14.4,Use the five competitive forces model to analyze competition in an industry.,The Five Competitive Forces Model,Mic

45、hael Porter of Harvard Business School identifies five separate competitive forces that determine the overall level of competition in an industry: Existing firms Example: Educational Testing Service administers the SAT ($51) and GRE ($150) tests. The SAT has competition from the ACT, helping keep its price low. The GRE has no similar competitor. Threat from new entrants Example: In the previous section, Apple charged a low price to deter Dell from entering its market.,The Five Competitive Forces Modelcontinued,Competition from substitutes Example: P