17,垄断竞争.pptVIP

Monopolistic Competition垄断竞争 Chapter 17 市场结构的四种类型 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。 寡头 只有少数几个卖者的市场，每个卖者提供与其他企业相似或相同的产品。 垄断竞争市场的特征 许多卖者 产品的差异性 自由进入和退出 许多卖者 许多厂商竞争同一群消费者. 产品举例： books, CDs, movies, computer games, restaurants, piano lessons, cookies, furniture, etc. 产品的差异性 每个厂商生产与别的厂商略微不同的产品. 与竞争厂商不同，垄断竞争厂商面对一条向下倾斜的曲线. 自由进入和退出 厂商的退出和进入没有限制. 只要厂商有超额利润，厂商的进入和退出就会发生. 短期的垄断竞争... 短期垄断竞争... 短期垄断竞争 短期的超额利润引来新进入者，由此: 增加了产品的供给量. 市场原有的垄断竞争厂商需求减少，利润下降. 短期的亏损使垄断竞争厂商退出 减少消费者选择的产品 原有厂商的需求增加 长期的垄断竞争 垄断竞争与完全竞争比较 —excess capacity — markup. Excess Capacity过剩生产能力... Markup Over Marginal Cost高于边际成本的加成... Advertising 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. 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. Advertising Critics of advertising argue that firms advertise in order to manipulate people’s tastes. They also argue that it impedes competition by implying that products are more different than they truly are. 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. Brand Names Critics argue that brand names cause consumers to perceive differences that do not really exist. 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. Summary A monopolistically competitive market is characterized by three attributes: many firms, differentiat