ch08-The Economics of the Public Sector

曼昆微观经济学分册英文版 教材PPT

8

The Economics of the Public Sector Externalities 公共部门经济学 8.1 Externalities( see Textbook Chapter 10 ) 外部性 (见教材第10章) 见教材第10章N. G R E G O R Y M A N K I WPremium PowerPoint® Slides by Ron Cronovich 2008 update© 2008 South-Western, a part of Cengage Learning, all rights reserved

曼昆微观经济学分册英文版 教材PPT

In this chapter, look for the answers to these questions:What is an externality? Why do externalities make market outcomes inefficient? How can people sometimes solve the problem of externalities on their own? Why do such private solutions not always work? What public policies aim to solve the problem of externalities?

1

曼昆微观经济学分册英文版 教材PPT

Introduction 简介Recall one of the Ten Principles from Chap. 1: Markets are usually a good way to organize economic activity. Lesson from Chapter 7: In the absence of market failures, the competitive market outcome is efficient, maximizes total surplus.

2

曼昆微观经济学分册英文版 教材PPT

Introduction 简介One type of market failure: externalities. Externality: the uncompensated impact of one person’s actions on the well-being of a bystander Negative externality: the effect on bystanders is adverse Positive externality: the effect on bystanders is beneficial

3

曼昆微观经济学分册英文版 教材PPT

Introductio 简介Self-interested buyers and sellers neglect the external effects of their actions, so the market outcome is not efficient. Another principle from Chapter 1: Governments can sometimes improve market outcomes.

4

曼昆微观经济学分册英文版 教材PPT

Pollution: A Negative Externality 环境污染： 环境污染：负外部性Example of negative externality: Air pollution from a factory.

The firm does not bear thefull cost of its production, and so will produce more than the socially efficient quantity. How govt may improve the market outcome:

Impose a tax on the firm equal to theexternal cost of the pollution it generates5

曼昆微观经济学分册英文版 教材PPT

Other Examples of Negative Externalities 负外部性的其他例子the neighbor’s barking dog late-night stereo blasting from the dorm room next to yours noise pollution from construction projects talking on cell phone while driving makes the roads less safe for others health risk to others from second-hand smoke

6

曼昆微观经济学分册英文版 教材PPT

Positive Externalities from Education 教育的的正外部性A more educated population benefits society: lower crime rates: educated people have more opportunities, are less likely to rob and steal better government: educated people make better-informed voters People do not consider these external benefits when deciding how much education to “purchase” Result: market eq’m quantity of education too low How govt may improve the market outcome: subsidize cost of education7

曼昆微观经济学分册英文版 教材PPT

Other Examples of Positive Externalities

正外部性的其他例子Being vaccinated against contagious diseases protects not only you, but people who visit the salad bar or produce section after you. R&D creates knowledge others can use. Renovating your house increases neighboring property values.Thank you for not contaminating the

fruit supply!8

曼昆微观经济学分册英文版 教材PPT

Recap of Welfare Economics重温福利经济学 重温福利经济学P $54 3 $2.50 2 1 0 0 10

The market for gasoline

The market eq’m maximizes consumer + producer surplus. Supply curve shows private cost, the costs directly incurred by sellers Demand curve shows private value, the value to buyers (the prices they are willing to pay)

20 25 30 Q (gallons)9

曼昆微观经济学分册英文版 教材PPT

Analysis of a Negative Externality

负的外部性的分析P $54 3 2 1 0 0 10 20

The market for gasoline Social cost = private + external costexternal cost Supply (private cost)

External cost = value of the negative impact on bystanders = $1 per gallon (value of harm from smog, greenhouse gases)10

30 Q (gallons)

曼昆微观经济学分册英文版 教材PPT

Analysis of a Negative Externality 负的外部性的分析P $54 3 2 1 0 0 10 20 D

The market for gasoline

Social The socially cost optimal quantity is 20 gallons. S

At any Q < 20, value of additional gas exceeds social cost At any Q > 20, social cost of the last gallon is greater than its value11

2530 Q (gallons)

曼昆微观经济学分册英文版 教材PPT

Analysis of a Negative Externality 负的外部性的分析P $54 3 2 D 1 0

The market for gasolineSocial cost S

Market eq’m (Q = 25) is greater than social optimum (Q = 20) One solution: tax sellers $1/gallon, would shift supply curve up $1.12

0

10

20

25

30 Q (gallons)

曼昆微观经济学分册英文版 教材PPT

“Internalizing the Externality” 外部性的内在化Internalizing the externality: altering incentives so that people take account of the external effects of their actions In our example, the $1/gallon tax on sellers makes sellers’ costs = social costs. When market participants must pay social costs, market eq’m = social optimum. (Imposing the tax on buyers would achieve the same outcome; market Q would equal optimal Q.)

13

曼昆微观经济学分册英文版 教材PPT

Positive Externalities 正的外部性In the presence of a positive externality, the social value of a good includes private value – the direct value to buyers external benefit – the value of the positive impact on bystanders The socially optimal Q maximizes welfare: At any lower Q, the social value of additional units exceeds their cost. At any higher Q, the cost of the last unit exceeds its social value.

14

曼昆微观经济学分册英文版 教材PPT

1: Analysis of a posi …… 此处隐藏：3410字，全部文档内容请下载后查看。喜欢就下载吧 ……