2福利经济学基础

单击此处编辑母版标题样式,单击此处编辑母版文本样式,第二级,第三级,第四级,第五级,*,第二讲 财政学的福利经济学基础（标准分析工具）,政府的经济活动多种多样，评价种种不同的政府行为的合理性需要有一个一般性框架。,财政学领域的大多数专家使用的评价分析框架是福利经济学。,本讲介绍福利经济学的根本内容，用以区分哪些情况市场运作自发带来理想结果，哪些情况市场无法产生理想结果。,1,第二讲 财政学的福利经济学基础,一、福利经济学（Welfare Economics）,1 Pure Economy Exchange,2 Production Economy,二、福利经济学第一根本定理,三、公平与福利经济学第二根本定理,四、市场失败,五、福利经济学的局限,2,一、福利经济学,福利经济学,:,The branch of economic theory concerned with the social desirability of alternative economic state.,3,1.,简单经济交换（没有生产）,埃奇沃斯盒形图Edgeworth Box,帕累托效率Pareto efficient allocation:No person can be better off without making another person worse off.,帕累托改进Pareto improvement:a reallocation of resources that makes one person better off without making anyone else worse off.,契约曲线Contract curve:the locus of all the Pareto efficient points.,Pareto efficiency requires that the marginal rate of substitution be equal for all consumers,4,Edgeworth Box:A device used to depict the distribution of goods in a two good-two person world.,5,无差异曲线,Indifference curves in an Edgeworth Box,6,Making Adam better off without Eve becoming worse off,7,Making Eve better off without Adam becoming worse off,8,Making both Adam and Eve better off,9,Starting from a different initial point,Edgeworth Box,Adam,Eve,0,0,s,r,Apples per year,Fig leaves per year,A,g,E,g,g,p,1,p,E,p2,A,p2,p,2,p,3,p,4,k,10,Contract curve:The locus of all the Pareto efficient points.(,契约曲线,),Edgeworth Box,Adam,Eve,0,0,s,r,Apples per year,Fig leaves per year,A,g,E,g,g,p,1,p,E,p2,A,p2,p,2,p,3,p,4,The contract curve,11,Pareto Efficiency in Consumption,消费效率条件,MRS,af,=MRS,af,在纯交换经济下，帕累托效率的实现条件为社会所有成员的边际替代率相等,Adam,Eve,12,2,生产经济,Production,Economy,（有生产，有交换）,生产可能性曲线,The production possibilities curve,边际转换率,The marginal rate of transformation,产品组合效率条件,Efficiency conditions with variable production,13,生产可能性曲线,Production possibilities curve:A graph that shows the maximum quantity of one output that can be produced,given the amount of the other output.,14,斜率,=MRS,消费者为了多消费一个苹果，愿意放弃几片无花果叶,消费者无差异曲线,苹果,无花果叶,60,100,生产可能性曲线,斜率,=MRT,为了多生产一个苹果,需要放弃几片无花果叶,产品组合效率要求,MRS=MRT,C,Efficiency Conditions with variable production,15,边际转换率,Marginal Rate of Transformation,MRT,af,=Marginal rate of transformation of apples for fig leaves,MRT,af,=MC,a,/MC,f,16,帕累托效率条件,MRT,af,=MRS,af,=MRS,af,MC,a,/MC,f,=MRS,af,=MRS,af,Adam,Eve,Adam,Eve,17,二、福利经济学第一根本定理The First Fundamental Theorem of Welfare Economics,As long as producers and consumers act as perfect competitors,that is,take prices as given,then under certain conditions,a Pareto efficient allocation of resources emerges.,只要生产者和消费者扮演完全竞争者的角色，即接受给定的价格,竞争的经济会“自动实现帕累托有效的资源配置。,18,三、,Fairness and the second fundamental theorem of welfare economics,If properly functioning competitive markets allocate resources efficiently,what role does the government have to play in the economy?,效率不是决定某种资源配置好坏的惟一标准。即使经济实现了帕累托效率，为了效用分配更加公平，政府仍有必要干预经济。,19,Efficiency versus Equity,Edgeworth Box,Adam,Eve,0,0,s,r,Apples per year,Fig leaves per year,q,p,5,p,3,20,效用可能性曲线,:It shows the maximum amount of one persons utility given the other individuals utility level.,Eves,utility,Adams utility,U,U,p,3,q,p,5,21,社会无差异曲线,Social Indifference Curve,Eves,utility,Adams utility,W=F(U,Adam,U,Eve,),Increasingsocialwelfare,22,Maximizing Social Welfare,Eves,utility,Adams utility,i,ii,iii,23,福利经济学第二根本定理：,在完全竞争的市场条件下，政府所要做的事情是改变个人之间禀赋的初始分配状态，其余的一切都可以由市场来解决。每一种具有帕累托效率的资源配置都可以通过市场机制实现。,24,四、市场失败 Market Failure,市场势力,Market Power,垄断,monopoly,市场不存在,Nonexistence of Markets,信息不对称,asymmetric information,外部性,externality,公共商品,public good,25,Overview,The First Welfare Theorem of states that a properly working competitive economy generates a Pareto efficient allocation of resources without any government intervention.However,it is not obvious that an efficient allocation of resources is per se socially desirable;some argue that fairness must also be considered.Moreover,competition may not hold and not all markets may exist in real-world economies.Hence,the market-determined allocation of resources is unlikely to be efficient.There are,then opportunities for government to intervene and enhance economic efficiency.,26,Overview,The fact that the market-generated allocation of resources is imperfect does not necessarily mean the government is capable of doing better.,Moreover,governments,like people,can make mistakes.,27,五、福利经济学的局限,Individualistic outlook:Welfare Economics is based on an individualistic social philosophy.,Merit goods:A commodity that ought to be provided even if people do not demand it,28,Results orientation:Welfare Economics concerns only the results,it does not pay much attention to the processes used to achieve results.,Coherent framework for analyzing policy,Will it have desirable distributional consequences?,Will it enhance efficiency?,Can it be done at a reasonable cost?,29,Homework,Discussion questions,30,