曼昆经济学原理Chap10.ppt

Externalities 外部性 Chapter 10 Market Efficiency - Market Failures 市场效率和市场失败 Recall that: Adam Smith’s “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. 尽管有看不见的手，市场失败还是有时发生 Market Failures: Externalities市场失败：外部性 When a market outcome affects parties other than the buyers and sellers in the market, side-effects are created called externalities. 市场结果除了影响买卖双方，如果还影响到市场中的其他人，这种关联结果被叫做外部性 Externalities cause markets to be inefficient, and thus fail to maximize total surplus.外部性引起市场失效，因而不能最大化总剩余 An externality arises...外部性在此时产生 . . . 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.一个人的行为影响了旁观者的福利，但并不为此付出或收到任何补偿 Market Failures: Externalities When the impact on the bystander is adverse, the externality is called a negative externality负的外部性. When the impact on the bystander is beneficial, the externality is called a positive externality正的外部性. Examples of Negative Externalities Automobile exhaust汽车尾气 Cigarette smoking抽烟 Barking dogs (loud pets)大宠物嚎叫 在你的鼓里有个好东西 Loud stereos in an apartment building 公寓里的立体音响 Examples of Positive Externalities Immunizations免疫 Restored historic buildings 重修历史建筑 Research into new technologies 研究新技术 The Market for Aluminum...铝市场 The Market for Aluminum and Welfare Economics铝市场和福利经济学 The quantity produced and consumed in the market equilibrium is efficient in the sense that it maximizes the sum of producer and consumer surplus. The Market for Aluminum and Welfare Economics铝市场和福利经济学 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. The Market for Aluminum and Welfare Economics铝市场和福利经济学 For each unit of aluminum produced, the social cost includes the private costs of the producers