微观经济学英文课件Ch_10.ppt

1、Externalities外部性,Chapter 10,Market Efficiency-Market Failure市场效率和市场失灵,Recall that: Adam Smiths “invisible hand” of the marketplace leads self-interested buyers and sellers in a market to maximize the total benefit that society can derive from a market. 市场中看不见的手会引导自利的买卖双方的行为，使得社会总福利最大化。 But market fa

2、ilures can still happen. 但是市场可能会失灵 Market failure results from market power and externality 市场垄断和外部性会导致市场失灵,Market Failures: Externalities市场失灵：外部性,When a market outcome affects parties other than the buyers and sellers in the market, side-effects are created called externalities. 当市场结果影响了买卖双方之外的人，这种

3、副作用我们就称为外部性。 Externalities cause markets to be inefficient, and thus fail to maximize total surplus. 外部性会使得市场缺乏效率，因此不能最大化总剩余。 when a person engages in an activity that influences the well-being of a bystander and yet neither pays nor receives any compensation for that effect, an externality arises.

4、当一个人从事某种活动时，影响到了旁观者的福利，并且没有因此付出代价或收到补偿，我们就说有外部性产生。,When the impact on the bystander is adverse, the externality is called a negative externality. 如果对旁观者的影响是不利的（不合意的），这种外部性就称为负的外部性。 When the impact on the bystander is beneficial, the externality is called a positive externality. 如果这种外部性是有益的，则称为正的外部性。

5、,Market Failures: Externalities市场失灵：外部性,Examples of Negative Externalities负的外部性的例子,Automobile exhaust Cigarette smoking Barking dogs (loud pets) Loud stereos in an apartment building Stinky Toufu,Immunizations（接种疫苗） Restored historic buildings 保护历史建筑 Research into new technologies 研究新技术,Examples of

6、Positive Externalities正的外部性的例子,The Market for Aluminum.,Quantity of Aluminum,0,Demand (private value),Supply (private cost),The Market for Aluminum and Welfare Economics,The quantity produced and consumed in the market equilibrium is efficient in the sense that it maximizes the sum of producer and c

7、onsumer surplus. If the aluminum factories emit pollution (a negative externality), then the cost to society of producing aluminum is larger than the cost to aluminum producers. For each unit of aluminum produced, the social cost includes the private costs of the producers plus the cost to those bys

8、tanders adversely affected by the pollution.,Pollution and the Social Optimum.,Quantity of,Aluminum,0,Demand,(private value),Supply,(private cost),Negative Externalities in Production生产中的负的外部性,The intersection of the demand curve and the social-cost curve determines the optimal output level. 需求曲线和社会

9、成本曲线的交点决定了最优的产出水平 The socially optimal output level is less than the market equilibrium quantity. 社会最优的产出水平比市场均衡产量要小。,Achieving the Socially Optimal Output,Internalizing an externality involves altering incentives so that people take into account the external effects of their actions. 将外部性内部化改变了激励，这

10、样人们决策时会考虑他们行为的外部作用。 The government can internalize an externality by imposing a tax on the producer to reduce the equilibrium quantity to the socially desirable quantity. 政府可以通过对生产者征税来内部化外部性，将均衡产量降低到社会合意产量。,Positive Externalities in Production生产中的正的外部性,When an externality benefits the bystanders, a

11、positive externality exists. The social costs of production are less than the private cost to producers and consumers. 生产的社会成本比生产者和消费者的私人成本更低。 A technology spillover is a type of positive externality that exists when a firms innovation or design not only benefits the firm, but enters societys pool o

12、f technological knowledge and benefits society as a whole.,Quantity,of Robots,0,Demand,(private value),Supply (private cost),Positive Externalities in Production,The intersection of the demand curve and the social-cost curve determines the optimal output level. The optimal output level is more than

13、the equilibrium quantity. The market produces a smaller quantity than is socially desirable. 市场生产量小于社会合意的产量。 The social costs of production are less than the private cost to producers and consumers.,Positive Externalities in Production,Internalizing Externalities: Subsidies,Government many times use

14、s subsidies as the primary method for attempting to internalize positive externalities. 政府通常使用补贴来将正的外部性内部化。,Technology Policy技术政策,Government intervention in the economy that aims to promote technology-enhancing industries is called technology policy. 着眼于推动技术进步的政府对经济的干预政策成为技术政策。 Patent laws are a for

15、m of technology policy that give the individual (or firm) with patent protection a property right over its invention. 专利法是技术政策的一种，它对私人发明产权进行专利保护。 The patent is then said to internalize the externality. 据说专利可以内部化外部性。,Internalizing Production Externalities内部化生产外部性,Taxes are the primary tools used to i

16、nternalize negative externalities. 税收是内部化负的外部性时的首选工具。 Subsidies are the primary tools used to internalize positive externalities. 补贴是内部化正的外部性时的首选工具。,Quantity of,Education,0,Price of,Education,Q,MARKET,Demand,(private value),Social,value,Q,OPTIMUM,(b) Positive Consumption Externality,Supply,(private

17、cost),Quantity,of Alcohol,0,Price,of Alcohol,Q,MARKET,Demand (private value),Supply,(private cost),Social value,Q,OPTIMUM,(a) Negative Consumption Externality,Consumption Externalities消费外部性,Consumption Externalitiesand Market Inefficiency,Negative externalities in production or consumption lead mark

18、ets to produce a larger quantity than is socially desirable. 生产和消费中的负的外部性使得市场生产的数量比社会合意的数量要多。 Positive externalities in production or consumption lead markets to produce a larger quantity than is socially desirable. 生产和消费中的正的外部性使得市场生产的数量比社会合意的数量要少。,Private Solutions to Externalities外部性的私人解决方法,Govern

19、ment action is not always needed to solve the problem of externalities. 解决外部性问题时并不总是需要政府。 Types of private solutions Moral codes and social sanctions 道德准则和社会制裁 Charitable organizations 慈善组织 Integrating different types of businesses 整合不同的业务 Contracting between parties 订立合同,The Coase Theorem科斯定理,The C

20、oase Theorem states that if private parties can bargain without cost over the allocation of resources, then the private market will always solve the problem of externalities on its own and allocate resources efficiently. 科斯定理表明，如果私人能够就资源分配进行没有成本的谈判，则私人市场自身就能解决外部性问题，并且有效地配置资源。,The Coase Theorem,The C

21、oase Theorem says that private economic actors can solve the problem of externalities among themselves. Whatever the initial distribution of rights, the interested parties can always reach a bargain in which everyone is better off and the outcome is efficient.,CoaseTheorem: More Example,A and B are

22、roommate, A like rock music and B prefer quiet. Suppose As willingness to pay for music is $50 while Bs willingness to pay for quiet is $40. Think about the institutional arrangement as follows: I. A has the right to play music II. B has the right to require quiet What will happen if As value for mu

23、sic is $40 while Bs value for quiet is $50? Some Important Concept: Property rights Coasian Bargaining Transaction Cost Coase Theorem is the guideline for us to figure out the right reason for market inefficiencies. Wrong reasons: Externality itself, unjustable property rights, wrong distribution of

24、 property rights Right reasons: ambiguous initial property rights, bargaining failure (transaction cost too high), restrictions on transfer of property rights. Another example: 宿舍熄灯安排 Equity Efficiency: transaction cost, credibility of admittance(difficult to enforce a contract), multiperson,informa

25、tion.,Why Private Solutions Do Not Always Work,Transaction costs are the costs that parties incur in the process of agreeing to and following through on a bargain. 交易成本是各方在谈判和达成协议的过程中产生的费用。 Sometimes the private solution approach fails because transaction costs can be so high that private agreement

26、is not possible. 有时因为交易成本太高私人不能达成协议，则私人的解决方法失灵。,Public Policy toward Externalitoies,When externalities are significant and private solutions are not found, government may attempt to solve the problem through . . . 如果外部性很显著而且私人方法不起作用，政府会通过下列手段来试图解决问题： command-and-control policies. 指令性政策 market-based

27、policies. 基于市场的政策,Command-and-Control Policies指令性政策,Usually take the form of regulations: Forbid certain behaviors. Require certain behaviors. Examples: Requirements that all students be immunized. Stipulations on pollution emission levels set by the Environmental Protection Agency (EPA).,Market-bas

28、ed Policies,Government uses taxes and subsidies to align private incentives with social efficiency. Pigovian taxes are taxes enacted to correct the effects of a negative externality.,Examples of Regulation versus Pigovian tax,If the EPA decides it wants to reduce the amount of pollution coming from

29、a specific plant. The EPA could tell the firm to reduce its pollution by a specific amount (i.e. regulation). levy a tax of a given amount for each unit of pollution the firm emits (i.e. Pigovian tax).,Market-based Policies,Tradable pollution permits allow the voluntary transfer of the right to poll

30、ute from one firm to another. A market for these permits will eventually develop. A firm that can reduce pollution at a low cost may prefer to sell its permit to a firm that can reduce pollution only at a high cost.,The Equivalence of Pigovian Taxes and Pollution Permits.,Quantity of,Pollution,0,Price of,Pollution,P,Q,Demand for,pollution rights,Pigovian,tax,(a) Pigovian Tax,2. .which, together with the demand curve, determines the quantity of pollution.,1. A Pigovian tax sets the price of pollution.,Quantity of,Poll