AP經(jīng)濟(jì)學(xué)ppt課件.ppt

1、AP經(jīng)濟(jì)學(xué)課件（部分） 主講：傅瑩,Lesson 11,Monopoly Market 完全壟斷市場(chǎng) (Chap 15 in Mankiws book and P45-48 in AP Economics ) You will learn: the characteristics of pure monopoly market and pure monopolist How will monopolists make decisions about the Price, Quantity, Revenue and Profit Inefficiency of Monopoly Public o

2、pinion towards monopoly Price discrimination,The characteristics of pure monopoly market and pure monopolist 完全壟斷市場(chǎng)和完全壟斷 生產(chǎn)者的特點(diǎn),The Characteristics of Pure Monopolist,A firm is considered a pure monopolist if it is the sole seller of its product. Pure monopoly are relatively rare. In our discussion,

3、 we regard less pure monopolies and near-monopolies as the kind of pure monopolist.,Pure Monopolist, Less Pure monopolist and near-monopolist,There are many examples of less pure monopolies. E.g. government-owned or government-regulated public utilities-natural gas and electric companies, the water

4、company. There are also many “near-monopolies”in which a single firm has a bulk of sales in a specific market. E.g. Intel provides 80% of the central microprocessors used in personal computers.,The Characteristics of Pure Monopolist(continued),Its product does not have any close substitutes. A pure

5、monopoly firm is a price maker. The fundamental cause of monopoly is barriers to entry.,Different Levels of Barrier to Entry,In pure monopoly market, strong barriers to entry block all potential competition. Somewhat weaker barriers may permit oligopoly, a market structure dominated by few firms. St

6、ill weaker barriers may permit the entry of a fairly large number of competing firms giving rise to monopolistic competition. Finally, the absence of any effective entry barriers permits the entry of a very large number of firms, which provide the basis of pure (perfect) competition.,WHY MONOPOLIES

7、ARISE,One single firm owns a key resource. (e.g. At one time the International Nickel Company of Canada, Inco, controlled 90% of the worlds known nickel reserves.) One single firm owns the patent for a certain product. The government gives a single firm the exclusive right to produce some good.(E.g.

8、 China State Grid) Political reasons, Protecting reasons etc. Natural Monopoly industry,How will monopolists make decisions about the Price, Quantity, Revenue and Profit 完全壟斷企業(yè)如何決定價(jià)格、生產(chǎn)數(shù)量、收益和利潤(rùn),A Monopolists Total Revenue, Average Revenue, and Marginal Revenue,Copyright2004 South-Western,P MR,P MR,A

9、 Monopolists Revenue,A Monopolists Marginal Revenue A monopolists marginal revenue is always less than the price of its good. (MR P) The demand curve is downward sloping. When a monopolist drops the price to sell one more unit, the revenue received from previously sold units also decreases.,Demand C

10、urve for Competitive firm and a Monopolist,Copyright 2004 South-Western,Quantity of Output,(a) A Competitive Firm,s Demand Curve,(b) A Monopolist,s Demand Curve,0,Price,Quantity of Output,0,Price,Demand Curve and Marginal-Revenue Curves for a Monopoly,Copyright 2004 South-Western,When a monopoly inc

11、reases the amount it sells, it has two effects on total revenue (P Q). The output effectmore output is sold, so Q is higher. The price effectprice falls, so P is lower,Quantity of Water,Price,$11,10,9,8,7,6,5,4,3,2,1,0,1,2,3,4,1,2,3,4,5,6,7,8,Elasticity and the TR Curve(recall),MR,d(AR=P),TR,Ed=1,El

12、astic Ed 1,Inelastic Ed 1,壟斷廠商需求曲線的特征決定其收益曲線的特征Total Revenue (Thousands of Dollars),A Monopolists Total, Average, and Marginal Revenue,Copyright2004 South-Western,MR is positive,MR is negative,MR =0,When a monoplist lowers the price, it lowers the MR,Monopoly Total Revenue, Marginal Revenue and Elas

13、ticity,Elastic,Inelastic,Demand and Marginal-Revenue Curves,Total-Revenue Curve,D,MR,TR,10-16,Marginal revenue is positive while total revenue is increaing. When total revenue reaches its maximum, marginal revenue is zero. When total revenue is diminishing, marginal revenue is negative.,2012 Mic 1 (

14、b) Question: If Steverail raised its price above Pm identified in part (a)(i), would total revenue increase, decrease, or not change? Explain.,2012. Micro 1 (b),Answer: Total revenue would decrease because the demand is price elastic in that range of the demand curve.(Or because MR 0). (12% answered

15、 correctly),Profit Maximization for a Monopolist (利潤(rùn)最大化）,Copyright 2004 South-Western,Quantity,Q,0,Costs and,Revenue,A Monopolists Profit,Profit = TR - TC Profit = (TR/Q - TC/Q) Q Profit = (P - ATC) Q,The Monopolists Economic Profit (經(jīng)濟(jì)利潤(rùn)）,Copyright 2004 South-Western,Quantity,0,Costs and,Revenue,Th

16、e monopolist will receive economic profits as long as price is greater than average total cost. (P ATC),The Monopolists Economic Loss(經(jīng)濟(jì)虧損） 2012 FRQ(1),Inefficiency of Monopolists (壟斷的無效率性） You will learn: (1) the inefficiency and deadweight loss of monopolists (2) the response of government for mon

17、opolists,Recall : Efficiency of Competitive firms,Allocative efficiency requires that resources be apportioned among firms and industries to yield the mix of products and services tht most wanted by society. The money price of any product is societys measure of the relative worth of an additional un

18、it of that product- for example, cucumbers. So the price of a unit of cucumbers is the marginal benefit derived from that unit of the product. Similarly, we see that the marginal cost of additional unit of a product measures the value of the other resources are drawn away from producing other goods.

19、 P=MC At equilibrium quantity , the combined amount of consumer surplus and producer surplus is maximized,The Efficiency of the Equilibrium Quantity,Copyright2003 Southwestern/Thomson Learning,Quantity,Price,0,Consumer and Producer Surplus in the Market Equilibrium ( Market efficiency),Copyright2003

20、 Southwestern/Thomson Learning,Price,0,Quantity,Efficiency losses (Deadweight loss),D,S,Price (Per Bag),P1,Q1,Quantity (Bags),Efficiency,Losses,Q2,Q3,6-27,Quantitly levles less than or greater than the efficient quantity, Q1, create efficiency losses. The trangle dbe shows the efficiency loss associ

21、ated with underproduction Q2, where the triangle bfg illustrates the efficiecy loss associated with overproduction Q3.,Inefficiency of Monopolist,In contrast to a competitive firm, the monopoly charges a price above the marginal cost. (P MC), then not all customers who value the good above its cost

22、can buy it. From the standpoint of consumers, this high price makes monopoly undesirable. However, from the standpoint of the owners of the firm, the high price makes monopoly very desirable. Few transaction are made under monopoly, which produce deadweight loss.,The Inefficiency of Monopoly,Copyrig

23、ht 2004 South-Western,Because a monopoly sets its price above marginal cost, it places a wedge between the consumers willingness to pay and the producers cost. This wedge causes the quantity sold to fall short of the social optimum.,Quantity,0,Price,The Monopolists efficiency and Deadweight loss,Cop

24、yright 2004 South-Western,Quantity,0,Costs and,Revenue,Compare : The deadweight loss of tax,Copyright 2004 South-Western,Quantity,0,Price,Deadweight loss from large tax,Copyright 2004 South-Western,Quantity,0,Price,(c) Large Tax,Chinese government Should Cut the Taxes.,The Deadweight Loss,The Ineffi

25、ciency of Monopoly The monopolist produces less than the socially efficient quantity of output. The deadweight loss caused by a monopoly is similar to the deadweight loss caused by a tax. The difference between the two cases is that the (1) government gets the revenue from a tax, (2) a private firm

26、gets the monopoly profit.,The condition for allocative efficiency is violated if (A) firms are price makers (price searchers) (B) short-run profits exist in a competitive industry (C) price equals average total cost (D) the market demand curve is inelastic in a competitive industry (E) the market de

27、mand curve is elastic in a competitive industry,Public policy towards Monopoly 處理完全壟斷的公共政策,PUBLIC POLICY TOWARD MONOPOLIES,Government responds to the problem of monopoly in one of four ways. Making monopolized industries more competitive. Regulating the behavior of monopolies. Turning some private m

28、onopolies into public enterprises. Doing nothing at all.,(1) Increasing Competition by antitrust law,Antitrust laws (反壟斷法) are a collection of statutes aimed at curbing monopoly power. Antitrust laws give government various ways to promote competition. They allow government to prevent mergers. They

29、allow government to break up companies. They prevent companies from performing activities that make markets less competitive. Two Important Antitrust Laws Sherman Antitrust Act (1890) Clayton Act (1914),(2) Regulation,Government may regulate the prices that the monopoly charges. The allocation of re

30、sources will be efficient if price is set to equal marginal cost.(P=MC) If P=MC, we realize the efficient allocation of social resources.,Monopoly Price,Fair-Return Price,Socially Optimal Price,Pr,D,r,f,b,a,Pf,Pm,Qm,Qf,Qr,MR,MC,ATC,10-39,P=MC Pricing Strategy,Marginal Cost Pricing for a Natural Mono

31、poly,Copyright 2004 South-Western,Quantity,0,Price,P=MC,In practice, regulators will allow monopolists to keep some of the benefits from lower costs in the form of higher profit, a practice that requires some departure from marginal-cost pricing.,(3) Turning some private monopolies into public enter

32、prises,Rather than regulating a natural monopoly that is run by a private firm, the government can run the monopoly itself (e.g. in the United States, the government runs the Postal Service). The purpose is to realize economic of scale and lower the cost.,(4) Doing Nothing,Government can do nothing

33、at all if the market failure is deemed small compared to the imperfections of public policies.,Price Discrimination 價(jià)格歧視,PRICE DISCRIMINATION,Price discrimination is the business practice of selling the same good at different prices to different customers, even though the costs for producing for the

34、 two customers are the same. Conditions Monopoly power ( at least some degree of monoply power) Market segregation (the seller must be able to segregate buyers into distinct classes) No resale (the original purchaser cannot resell the product or service),PRICE DISCRIMINATION,Perfect Price Discrimina

35、tion Perfect price discrimination refers to the situation when the monopolist knows exactly the willingness to pay of each customer and can charge each customer a different price. Two important effects of price discrimination: It can increase the monopolists profits. It can reduce deadweight loss.,M

36、onopolist with Single Price,Copyright 2004 South-Western,Price,0,Quantity,Monopolist with Perfect Price Discrimination,Copyright 2004 South-Western,Price,0,Quantity,一級(jí)價(jià)格歧視：對(duì)每一單位產(chǎn)品都按消費(fèi)者所愿意支付的最高價(jià)格出售，廠商剝奪了全部的消費(fèi)者剩余。 在此情況下資源的配置是有效率的。,MC,Qm,Qc,Pm,Pc,一級(jí)價(jià)格歧視,PEFECT PRICE DISCRIMINATION （first degree price d

37、iscrimination),PRICE DISCRIMINATION,Examples of Price Discrimination Movie tickets Airline prices Discount coupons Financial aid Quantity discounts,Natural Monopolies,Even at higher quantity produced, when a firms average total cost (ATC) will decrease as the quantity supplied increases. A natural m

38、onopoly arises when there are economies of scale over the relevant range of output. A natural monopolys lower unit cost would enable it to charge a lower price than if the industry were more competitive, but not necessarily happen. Natural monopolies industry: tap water, electricity, public transpor

39、tation etc.,自然壟斷的一個(gè)主要特征是廠商的平均成本在很高的產(chǎn)量水平上仍隨產(chǎn)量的增加而遞減。這方面是自然壟斷表現(xiàn)出的規(guī)模經(jīng)濟(jì)。 自然壟斷作為壟斷的一種形式，同樣存在著由于缺乏競(jìng)爭(zhēng)所造成的壟斷廠商高價(jià)格、高利潤(rùn)以及低產(chǎn)出水平等經(jīng)濟(jì)的效率損失。 對(duì)自然壟斷的爭(zhēng)論：政府對(duì)某些公用事業(yè)的壟 斷，不以追求壟斷利潤(rùn)為目的；對(duì)于完全壟斷 下的技術(shù)進(jìn)步人們持有著不同看法。,自然壟斷和政府管制,Economies of Scale as a Cause of Monopoly,Copyright 2004 South-Western,Quantity of Output,0,Cost,Economie

40、s of scale refer to the property whereby long-run average total cost falls as the quantity of output increases Economies of scale will serve as an entry barrier and will protect the monopolist from competition.,Typical Average Total Cost Curve,Copyright 2004 South-Western,Quantity of,Cars per Day,0,

41、Average,Total,Cost,Marginal Cost Pricing for a Natural Monopoly,Copyright 2004 South-Western,Quantity,0,Price,P=MC loss,In practice, regulators will allow monopolists to keep some of the benefits from lower costs in the form of higher profit, a practice that requires some departure from marginal-cos

42、t pricing.,管制機(jī)構(gòu)陷入 了兩難困境。 平均成本定價(jià) 法Then p=ATC no profit 是管制價(jià)格 等于平均成本,。,第一節(jié) 壟斷 七、自然壟斷和政府管制,MR,MC,ATC,d(AR),定價(jià)法,Monopoly Price,Fair-Return Price,Socially Optimal Price,Pr,D,r,f,b,a,Pf,Pm,Qm,Qf,Qr,MR,MC,ATC,10-56,Some key points in monopoly curves 完全壟斷市場(chǎng)中一些重要的點(diǎn)總結(jié),2011 Micro 1(a) (b),Answer,(a) monopoly p

43、rice = 24 MR=MC (b) 24-18=$6,2011. Micro 1 (c),Question: Assume that the monopolist is maximizing profit. Is allocative efficiency achieved? Explain.,Micro 1 (c),Price,Quantity,Demand,0,Marginal Revenue,Marginal Cost,PM,QM,QS,PS,2011. Micro 1 (c),Answer: No, because P MC / D MC / MSB MSC. (33% answe

44、red correctly),2011. Micro 1 (d),Question: Between the prices of $16 and $18, is the monopolist in the elastic, inelastic, or unit elastic portion of its demand curve. Explain.,Micro 1 (d) Answer,Price,Quantity,Demand,0,$16,Marginal Revenue,$18,11,12,Inelastic range,2011. Micro 1 (d),Answer: Demand

45、is inelastic because TR increases as price increases / MR is negative / the price elasticity is .74 1.,27% answered correctly,2011 Micro (e),2011. Micro 1 (e),Assume that regulators set an output of 11 units (i) Is the monopolist earning positive economic profit ? Explain. Answer: when Q=11, P=ATC, not earning economic profit. (ii) Is the monopolist earning positive accounting profit? Answer: Yes,2