1、第二講 財政學的福利經濟學基礎（標準分析工具） 政府的經濟活動多種多樣，評價種種不同的政府行為的合理性需要有一個一般性框架。 財政學領域的大多數專家使用的評價分析框架是福利經濟學。 本講介紹福利經濟學的根本內容，用以區分哪些情況市場運作自發帶來理想結果，哪些情況市場無法產生理想結果。 1第二講 財政學的福利經濟學基礎一、福利經濟學 （ Welfare Economics） 1 Pure Economy Exchange 2 Production Economy二、福利經濟學第一根本定理三、 公平與福利經濟學第二根本定理四、 市場失敗五、 福利經濟學的局限2一、福利經濟學 福利經濟學: The

2、branch of economic theory concerned with the social desirability of alternative economic state.31.簡單經濟交換 （沒有生產）埃奇沃斯盒形圖Edgeworth Box帕累托效率Pareto efficient allocation: No person can be better off without making another person worse off.帕累托改進Pareto improvement: a reallocation of resources that makes one

3、 person better off without making anyone else worse off.契約曲線Contract curve: the locus of all the Pareto efficient points.Pareto efficiency requires that the marginal rate of substitution be equal for all consumers 4Edgeworth Box: A device used to depict the distribution of goods in a two good-two pe

4、rson world.5無差異曲線 Indifference curves in an Edgeworth Box6Making Adam better off without Eve becoming worse off7Making Eve better off without Adam becoming worse off8Making both Adam and Eve better off9Starting from a different initial pointEdgeworth BoxAdamEve00srApples per yearFig leaves per yearA

5、gEggp1pEp2Ap2p2p3p4k10Contract curve: The locus of all the Pareto efficient points.(契約曲線)Edgeworth BoxAdamEve00srApples per yearFig leaves per yearAgEggp1pEp2Ap2p2p3p4The contract curve11Pareto Efficiency in Consumption消費效率條件MRSaf = MRSaf 在純交換經濟下，帕累托效率的實現條件為社會所有成員的邊際替代率相等AdamEve122 生產經濟Production Ec

6、onomy（有生產，有交換） 生產可能性曲線The production possibilities curve邊際轉換率The marginal rate of transformation 產品組合效率條件Efficiency conditions with variable production 13生產可能性曲線Production possibilities curve: A graph that shows the maximum quantity of one output that can be produced, given the amount of the other o

7、utput.14斜率=MRS消費者為了多消費一個蘋果，愿意放棄幾片無花果葉消費者無差異曲線蘋果無花果葉60100生產可能性曲線斜率=MRT為了多生產一個蘋果需要放棄幾片無花果葉產品組合效率要求MRS = MRTCEfficiency Conditions with variable production15邊際轉換率Marginal Rate of TransformationMRTaf = Marginal rate of transformation of apples for fig leavesMRTaf = MCa/MCf16帕累托效率條件MRTaf = MRSaf = MRSafM

8、Ca/MCf = MRSaf = MRSafAdamEveAdamEve17二、福利經濟學第一根本定理The First Fundamental Theorem of Welfare EconomicsAs 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.只要生產者和消費者扮演完全競爭者的角色，即接受

9、給定的價格,競爭的經濟會“自動實現帕累托有效的資源配置。 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?效率不是決定某種資源配置好壞的惟一標準。即使經濟實現了帕累托效率，為了效用分配更加公平，政府仍有必要干預經濟。19Efficiency

10、 versus EquityEdgeworth BoxAdamEve00srApples per yearFig leaves per yearqp5p320效用可能性曲線: It shows the maximum amount of one persons utility given the other individuals utility level.Eves utilityAdams utilityUUp3qp521社會無差異曲線Social Indifference CurveEves utilityAdams utilityW = F(UAdam, UEve)Increasing

11、socialwelfare22Maximizing Social WelfareEves utilityAdams utilityiiiiii23福利經濟學第二根本定理： 在完全競爭的市場條件下，政府所要做的事情是改變個人之間稟賦的初始分配狀態，其余的一切都可以由市場來解決。每一種具有帕累托效率的資源配置都可以通過市場機制實現。24四、市場失敗 Market Failure市場勢力 Market Power壟斷 monopoly市場不存在 Nonexistence of Markets信息不對稱 asymmetric information外部性 externality公共商品 public

12、good25OverviewThe 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 f

13、airness 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. 26Ov

14、erviewThe 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、福利經濟學的局限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 28Results orientation: Welfare Economics concerns only the results, it does not pay much attenti