资源描述
Click to edit Master title style,Click to edit Master text styles,Second Level,Third Level,Fourth Level,Fifth Level,Harcourt, Inc. items and derived items copyright 2001 by Harcourt, Inc.,Monopolistic Competition,垄断竞争,Chapter 17,Monopolistic Competition,垄断竞争,Imperfect competition refers to those market structures that fall between perfect competition and pure monopoly.,不完全竞争是指介于完全竞争与纯垄断之间的市场结构。,The Four Types of Market Structure,Monopoly,（,Chap15）,Oligopoly,(Chap16),Monopolistic Competition,(Chap17),Perfect Competition,（Chap14）,Tap water,Cable TV,Tennis balls,Crude oil,Novels,Movies,Wheat,Milk,Number of Firms?,Type of Products?,Many firms,One firm,Few firms,Differentiated products,Identical products,市场结构的四种类型,垄断,（15章）,寡头,（16章）,垄断竞争,（17章）,完全竞争,（14章）,自来水,有线电视,网球,原油,小说,电影,小麦,牛奶,企业数量?,产品类型？,许多企业,一家企业,几家,企业,有差别产量,相同产品,Types of Imperfectly Competitive Markets,Monopolistic Competition,Many firms selling products that are similar but not identical.,Oligopoly,Only a few sellers, each offering a similar or identical product to the others.,不完全竞争市场的类型,垄断竞争,许多出售相似但不相同产品的企业组成的市场结构。,寡头,只有很少卖者，出售相似或相同的产品。,Monopolistic Competition,垄断竞争,Markets that have some features of competition and some features of monopoly.,有某些竞争特点又有某些垄断特点的市场结构。,Attributes of Monopolistic competition,垄断竞争的特点,Many sellers,很多卖者,Product differentiation,产品有差异,Free entry and exit,自由进入和退出,Many Sellers,There are many firms competing for the same group of customers.,Product examples include books, CDs, movies, computer games, restaurants, piano lessons, cookies, furniture, etc.,很多卖者,有许多企业争夺同样的顾客群体。,产品例子包括书籍、,CD、,电影、电脑游戏、餐馆、钢琴课、点心、家居等等。,Product Differentiation,Each firm produces a product that is at least slightly different from those of other firms.,Rather than being a price taker, each firm faces a downward-sloping demand curve.,产品差异化,每个企业生产的一种产品至少与其他企业生产的这种产品略有不同。,每个企业不是价格接受者，而是面临一条向右下方倾斜的需求曲线。,Free Entry or Exit,Firms can enter or exit the market without restriction.,The number of firms in the market adjusts until economic profits are zero.,自由进入或退出,企业可以没有限制地进入或退出一个市场。,市场上企业的数量要一直调整到经济利润为零时为止。,Monopolistic Competition in the Short Run,Short-run economic profits encourage new firms to,enter the market,. This:,Increases the number of products offered.,Reduces demand faced by firms already in the market.,Incumbent firms demand curves shift to the left.,Demand for the incumbent firms products fall, and their profits decline.,短期中的垄断竞争企业,短期 经济利润激励新企业进入市场。这种进入,增加了顾客可以选择的产品数量。,减少了市场已有的每家企业面临的需求。,使市场已有企业面临的需求曲线向左移动。,市场已有企业的产品需求减少，利润下降。,Figure 1 Monopolistic Competition in the Short Run,Quantity,0,Price,Profit-,maximizing,quantity,Price,Demand,MR,ATC,(,a) Firm Makes Profit,Average,total cost,Profit,MC,图1. 短期中的垄断竞争企业,(,a),企业有利润,产量,0,价格,需求,MR,ATC,利润,MC,利润最大化产量,价格,平均,总成本,Monopolistic Competition in the Short Run,Short-run economic losses encourage firms to,exit the market,. This:,Decreases the number of products offered.,Increases demand faced by the remaining firms.,Shifts the remaining firms demand curves to the right.,Increases the remaining firms profits.,短期中的垄断竞争企业,短期经济亏损激励企业退出市场。随着企业退出：,顾客可选择的产品数量少了。,增加了继续留在市场中的企业面临的需求。,使继续留在市场中的企业的需求曲线向右移动。,使继续留在市场中的企业的利润增加。,Figure 1 Monopolistic Competitors in the Short Run,Demand,Quantity,0,Price,Price,Loss-,minimizing,quantity,Average,total cost,(,b) Firm Makes Losses,MR,Losses,ATC,MC,图1. 短期中的垄断竞争企业,产量,0,价格,需求,MR,亏损,(,b),企业亏损,MC,ATC,平均,总成本,利润最小化产量,价格,The Long-Run Equilibrium,长期均衡,Firms will enter and exit until the firms are making exactly zero economic profits.,企业进入或退出的过程一直持续到市场中的企业的经济利润正好是零时。,Figure 2 A Monopolistic Competitor in the Long Run,Quantity,Price,0,Demand,MR,ATC,MC,Profit-maximizing,quantity,P,=,ATC,图2. 长期中的垄断竞争者,产量,价格,0,需求,MR,ATC,MC,利润最大化产量,P=,ATC,Long-Run Equilibrium,Two Characteristics,As in a monopoly, price exceeds marginal cost.,Profit maximization requires marginal revenue to equal marginal cost.,The downward-sloping demand curve makes marginal revenue less than price.,As in a competitive market, price equals average total cost.,Free entry and exit drive economic profit to zero.,长期均衡,两个特点,正如在垄断市场上一样，价格大于边际成本。,利润最大化要求边际收益等于边际成本。,向右下方倾斜的需求曲线使边际成本小于价格。,正如在竞争市场上一样，价格等于平均总成本。,自由进入与退出使经济利润为零。,Monopolistic versus Perfect Competition,There are two noteworthy differences between monopolistic and perfect competition,excess capacity,and,markup.,垄断竞争与完全竞争,垄断竞争和完全竞争之间有两个值得注意的差别,过剩生产能力,和,价格加成。,Monopolistic versus Perfect Competition,Excess Capacity,There is no excess capacity in perfect competition in the long run.,Free entry results in competitive firms producing at the point where average total cost is minimized, which is the efficient scale of the firm.,There is excess capacity in monopolistic competition in the long run.,In monopolistic competition, output is less than the efficient scale of perfect competition.,垄断竞争与完全竞争,过剩生产能力,在长期中，完全竞争企业没有过剩生产能力。,竞争市场上的自由进入使企业生产平均总成本最小的产量，即企业的有效规模产量。,在长期中，垄断竞争企业存在过剩生产能力。,垄断竞争企业的产量低于完全竞争企业生产的有效规模产量。,Figure 3 Monopolistic versus Perfect Competition,Quantity,0,Price,Demand,(,a) Monopolistically Competitive Firm,Quantity,0,Price,P,=,MC,P,=,MR,(,demand,curve),(,b) Perfectly Competitive Firm,MC,ATC,MC,ATC,MR,Efficient,scale,P,Quantity,produced,Quantity produced =,Efficient scale,图,3.,垄断竞争与完全竞争,产量,(,a),垄断竞争企业,(,b),完全竞争企业,产量,价格,P = MR,(,需求曲线),MC,ATC,价格,需求,MC,ATC,过剩生产能力,生产量,有效规模,P = MC,产量,= 有效规模产量,P,Monopolistic versus Perfect Competition,Markup Over Marginal Cost,For a competitive firm, price equals marginal cost.,For a monopolistically competitive firm, price exceeds marginal cost.,Because price exceeds marginal cost, an extra unit sold at the posted price means more profit for the monopolistically competitive firm.,垄断竞争与完全竞争,高于边际成本的价格加成,对一个竞争企业来说，价格等于边际成本。,对一个垄断竞争企业来说，价格高于边际成本,。,因为垄断竞争企业的价格高于其边际成本，以牌价多销售出一个单位产品就意味着利润多了。,Figure 3 Monopolistic versus Perfect Competition,Quantity,0,Price,Demand,(,a) Monopolistically Competitive Firm,Quantity,0,Price,P,=,MC,P,=,MR,(,demand,curve),(,b) Perfectly Competitive Firm,Markup,MC,ATC,MC,ATC,MR,Marginal,cost,P,Quantity,produced,Quantity produced,图3. 高于边际成本的价格加成,产量,(,a),垄断竞争企业,(,b),完全竞争企业,产量,价格,P,=,MC,P,=,MR,(,需求曲线),MC,ATC,生产量,价格,P,需求,边际成本,MC,ATC,MR,价格加成,生产量,Figure 3 Monopolistic versus Perfect Competition,Quantity,0,Price,Demand,(,a) Monopolistically Competitive Firm,Quantity,0,Price,P,=,MC,P,=,MR,(,demand,curve),(,b) Perfectly Competitive Firm,Markup,Excess capacity,MC,ATC,MC,ATC,MR,Marginal,cost,Efficient,scale,P,Quantity,produced,Quantity produced =,Efficient scale,图3. 垄断竞争和完全竞争,产量,(,a),垄断竞争企业,(,b),完全竞争企业,产量,价格,P,=,MR,(,需求曲线),MC,ATC,生产量,有效规模,价格,P,需求,MC,ATC,P,=,MC,过剩市场能力,边际成本,价格加成,MR,生产量 = 有效规模,Monopolistic Competition and the Welfare of Society,垄断竞争与社会福利,Monopolistic competition does not have all the desirable properties of perfect competition.,垄断竞争不具有完全竞争所具有的令人合意的特性。,Monopolistic Competition and the Welfare of Society,There is the normal deadweight loss of monopoly pricing in monopolistic competition caused by the markup of price over marginal cost.,However, the administrative burden of regulating the pricing of all firms that produce differentiated products would be overwhelming.,垄断竞争与社会福利,垄断竞争市场存在由于高于边际成本的价格加成所导致的正常的无谓损失。,但是，管制所有生产差异产品的企业的管理负担将是巨大的。,Monopolistic Competition and the Welfare of Society,Another way in which monopolistic competition may be socially inefficient is that the number of firms in the market may not be the “ideal” one. There may be too much or too little entry.,垄断竞争与社会福利,垄断竞争可能引起社会无效率的另一个方面是市场上的企业数量可能并不是“理想”的数量，可能有太多或太少的企业进入。,Monopolistic Competition and the Welfare of Society,垄断竞争与社会福利,Externalities of entry include,:,进入的外部性包括：,product-variety externalities.,产品多样化外部性,business-stealing externalities.,抢走业务的外部性,Monopolistic Competition and the Welfare of Society,The,product-variety externality,:,Because consumers get some consumer surplus from the introduction of a new product, entry of a new firm conveys a,positive externality,on consumers.,The,business-stealing externality,:,Because other firms lose customers and profits from the entry of a new competitor, entry of a new firm imposes a,negative externality,on existing firms.,垄断竞争与社会福利,产品多样化外部性,:,由于消费者从新产品引进中得到了一些消费者剩余，所以存在与进入相关的,正外部性。,抢走业务的外部性,:,由于其它企业从与新进入者的竞争者中失去顾客和利润，,所以存在与进入相关的负外部性。,Advertising,广告,When firms sell differentiated products and charge prices above marginal cost, each firm has an incentive to advertise in order to attract more buyers to its particular product.,当企业销售有差异产品并收取高于边际成本的价格时，每个企业都有靠做广告来吸引更多顾客购买自己特殊产品的激励。,Advertising,Firms that sell highly differentiated consumer goods typically spend between 10 and 20 percent of revenue on advertising.,Overall, about 2 percent of total revenue, or over $100 billion a year, is spent on advertising.,广告,销售很大差异消费品的企业，通常都把收益的1020用于广告支出。,总体上，广告支出占企业总收益的2左右,或者在1 000亿美元以上。,Advertising,广告,Critics of advertising argue that firms advertise in order to manipulate peoples tastes.,广告的批评者认为，企业做广告是为了操纵人们的嗜好。,They also argue that it impedes competition by implying that products are more different than they truly are.,批评者还认为，广告抑制了竞争。广告努力使消费者相信产品差异大于实际情况。,Advertising,Defenders argue that advertising provides information to consumers,They also argue that advertising increases competition by offering a greater variety of products and prices.,The willingness of a firm to spend advertising dollars can be a,signal,to consumers about the quality of the product being offered.,广告,广告的辩护者认为，企业用广告向顾客提供信息。,辩护者还认为，广告加剧了竞争，为顾客提供了更多的产品和价格。,企业愿意用大量的钱来做广告，这本身就向消费者传递了一个所提供产品质量的信息。,Brand Names,品牌,Critics argue that brand names cause consumers to perceive differences that do not really exist.,品牌的批评者认为，品牌使消费者感觉到的产品差异大于实际存在的差异。,Brand Names,Economists have argued that brand names may be a useful way for consumers to ensure that the goods they are buying are of high quality.,providing,information,about quality.,giving firms,incentive,to maintain high quality.,品牌,经济学家对品牌的辩护是认为品牌是消费者保证他们购买的物品具有高质量的一种有用方法。,提供产品质量,信息。,向企业提供了保持高质量的,激励。,Summary,A monopolistically competitive market is characterized by three attributes: many firms, differentiated products, and free entry.,The equilibrium in a monopolistically competitive market differs from perfect competition in that each firm has excess capacity and each firm charges a price above marginal cost.,小结,垄断竞争市场有三个特点：许多企业、差异化的产品以及自由进入和退出。,垄断竞争市场均衡在相关的两个方面不同于完全竞争市场：每个企业有过剩生产能力，每个企业收取高于其边际成本的价格。,Summary,Monopolistic competition does not have all of the desirable properties of perfect competition.,There is a standard deadweight loss of monopoly caused by the markup of price over marginal cost.,The number of firms can be too large or too small.,小结,垄断竞争没有完全竞争所有合意的特点。,存在由高于边际成本的价格加成引起的标准无谓损失。,企业的数量（以及产品的种类）可能过多或过少。,Summary,The product differentiation inherent in monopolistic competition leads to the use of advertising and brand names.,Critics argue that firms use advertising and brand names to take advantage of consumer irrationality and to reduce competition.,Defenders argue that firms use advertising and brand names to inform consumers and to compete more vigorously on price and product quality.,小结,垄断竞争中固有的产品差异引起企业使用广告和品牌。,广告和品牌的批评者认为，企业用这些方法利用了消费者的缺乏理性，并减少了竞争。,广告与品牌的辩护者认为，企业用这些方法向消费者提供了信息，并使价格和产品质量的竞争更为激烈。,
展开阅读全文