产业经济学英文版课件(编辑修改稿)

产业经济学英文版课件(编辑修改稿)内容摘要：

et demand and its costs • – Choice of price, or equivalently, quantity • • Downward sloping demand allows • monopolist to exercise market power • – Static monopoly model no strategic behavior • – In future lectures consider possible strategic • behavior in more than one period models Chapter 3: Monopoly and Dominant firm • Market Power • • Monopolist has the most market power • possible • • Perfectly petitive firm has least market • power possible • – What is Lerner Index? • • Oligopolists fall in between • – Lerner indices greater than 0 but less than monopoly Chapter 3: Monopoly and Dominant firm • Monopoly Profit Maximization Chapter 3: Monopoly and Dominant firm • Marginal Revenue • • For a monopolist mr is not equal to price: – What does first term measure? – What does second term measure? Downward sloping demand implies first term is negative so mr is less than price Chapter 3: Monopoly and Dominant firm • Example: Linear Demand Chapter 3: Monopoly and Dominant firm • Example: Linear Demand and Constant Marginal Costs Chapter 3: Monopoly and Dominant firm • Monopoly Profits Chapter 3: Monopoly and Dominant firm • Price as Demand Rotates Chapter 3: Monopoly and Dominant firm • Market Power and Elasticity Chapter 3: Monopoly and Dominant firm • Inverse Relationship • • There is an inverse relationship between • demand elasticity and market power • • What does ε represent? Will this • relationship be true outside of monopoly? • – In general does ε depend on quantity (Q)? • – When does mc not depend on quantity (Q)? Chapter 3: Monopoly and Dominant firm • Estimated Demand Chapter 3: Monopoly and Dominant firm • RentSeeking • • Posner (1975) contends DWL • underestimates loss of social welfare • because of monopoly • – Argues that part of the producer surplus also • represents lost social welfare • – Monopolist might expend real resources trying • to obtain or maintain monopoly power • • Lobbying government • • Suing potential rivals in court (patent infringement) Chapter 3: Monopoly and Dominant firm • Measures of Efficiency • • Static efficiency • – Maximize social welfare in one time period • • Dynamic efficiency • – Maximize discounted present value of welfare • • May give up some today for big payoffs in future • • Ex: If innovation important, possible • monopoly is dynamically efficient while • statically inefficient Chapter 3: Monopoly and Dominant firm • Passthrough: Monopolist Chapter 3: Monopoly and Dominant firm • Passthrough: Monopolist Chapter 3: Monopoly and Dominant firm • Passthrough: Competition Chapter 3: Monopoly and Dominant firm • Natural Monopoly • • Natural monopoly: One firm can produce • market output at lower cost than more • than one firm • – Classic examples, now debated: utilities amp。 • cable • • Practically speaking there needs to be • large cost savings to justify the lack of petition Chapter 3: Monopoly and Dominant firm • Subadditivity • • Subadditivity: Cost of producing sum of • outputs less than the sum of the costs: • Cost subadditivity is a necessary condition • for the existence of a natural monopoly • –Decreasing AC implies subadditivity, but • can meet subadditivity requirement • without decreasing AC Chapter 4:Differentiated Goods • Chapter 4 • Differentiated Goods: Monopolistic Competition Chapter 4:Differentiated Goods • Types of Product Differentiation • • Horizontally differentiated products: • Valued differently across consumers • – Consumers disagree about ranking of goods • • Vertically differentiated products: • Consumers agree more of vertically • differentiating factor is better but may • value it at different levels • – Consumers agree about ranking of goods Chapter 4:Differentiated Goods • Cereal: Horizontal Differentiation • • Consider readytoeat breakfast cereals • • Clearly products are differentiated • – What are some of the characteristics that • differ across brands of cereals? • – Do preferences about these characteristics • vary across consumers or do all consumers • agree that “more” of some characteristic is • better? Chapter 4:Differentiated Goods Chapter 4:Differentiated Goods • Processors: Vertical Differentiation • Do consumers agree that a faster processor is better? • Are entire puters horizontally or vertically differentiated? Chapter 4:Differentiated Goods • Demand for Horizontally • Differentiated Goods • • Representative consumer: Demand is for • whole goods • – “Goods are goods” approach • – Chamberlin (1933) • • Characteristics approach: Demand is for • characteristics bundled into goods • – Address branch • – Hotelling (1929) amp。 Lancaster (1960‟s amp。 70‟s) Chapter 4:Differentiated Goods • Representative Consumer • • Representative consumer: A fictional • single consumer that represents the • behavior in aggregate of all M consumers • – Quantities purchased by the representative • consumer times M yield market quantities: Chapter 4:Differentiated Goods • Representative Consumer • • Assumes representative consumer has: • – Preferences over goods not the individual • features that make up the good • – A taste for variety • • Implication: The representative consumer • consumes a little bit of everything • • Usual approach in basic microeconomics: • – Indifference curves: quantity of goods on axes Chapter 4:Differentiated Goods • Monopolistic Competition • • Chamberlin (1933) noticed number of • industries with intense petition (many • firms) but differentiated goods • • Examples: • – Restaurant meals • – Shampoo • • Antitrust example: . vs. Oracle Chapter 4:Differentiated Goods • “Tweak”。