Chap02像经济学家一样思考经济学原理,曼昆,中英文双语

1、Thinking Like an Economist像经济学家一样思考像经济学家一样思考Chapter 2Harcourt, Inc. items and derived items copyright 2001 by Harcourt, Inc.Every field of study has its own terminologyMathematicsaxiomsintegralsvector spacesPsychologyegoidcognitive dissonanceLawtortsvenuesPromissory estoppelHarcourt, Inc. items and

2、derived items copyright 2001 by Harcourt, Inc.每个研究领域都有自己的语言每个研究领域都有自己的语言数学数学公理公理积分积分向量空间向量空间心理学心理学自我自我本我本我认知的认知的不一致性不一致性法律法律侵权行为侵权行为案发现场案发现场约定的禁止翻约定的禁止翻供供Harcourt, Inc. items and derived items copyright 2001 by Harcourt, Inc.Every field of study has its own terminologyEconomicsSupplyDemandElasticity

3、Consumer SurplusComparative advantageOpportunity costDeadweight lossHarcourt, Inc. items and derived items copyright 2001 by Harcourt, Inc.每个研究领域都有自己的语言每个研究领域都有自己的语言经济学经济学供给供给需求需求弹性弹性消费者剩余消费者剩余比较优势比较优势机会成本机会成本无谓损失无谓损失Harcourt, Inc. items and derived items copyright 2001 by Harcourt, Inc.Economics tr

4、ains you to. . . . uThink in terms of alternatives.uEvaluate the cost of individual and social choices.uExamine and understand how certain events and issues are related.Harcourt, Inc. items and derived items copyright 2001 by Harcourt, Inc.经济学训练你经济学训练你. . . . u从不同的角度思考问题。从不同的角度思考问题。u评估个人和社会选择的成本。评估个

5、人和社会选择的成本。u检查和理解一些事件和问题是如何相检查和理解一些事件和问题是如何相互关联的。互关联的。Harcourt, Inc. items and derived items copyright 2001 by Harcourt, Inc.The Economist as a Scientist作为科学家的经济学家作为科学家的经济学家The economic way of thinking . . . 经济学思考方法经济学思考方法uInvolves thinking analytically and objectively. 客观地分析与思考。客观地分析与思考。uMakes use o

6、f the scientific method. 利用利用科学的方法。科学的方法。Harcourt, Inc. items and derived items copyright 2001 by Harcourt, Inc.The Scientific MethoduUses abstract models to help explain how a complex, real world operates.uDevelops theories, collects, and analyzes data to prove the theories.Observation, Theory and

7、More Observation!Harcourt, Inc. items and derived items copyright 2001 by Harcourt, Inc.科学方法科学方法u利用抽象的模型帮助解释复杂的利用抽象的模型帮助解释复杂的真实世界如何运行。真实世界如何运行。u形成理论，收集并分析数据来验形成理论，收集并分析数据来验证理论。证理论。观察, 理论 ，更多的观察Harcourt, Inc. items and derived items copyright 2001 by Harcourt, Inc.The Role of Assumptionsu Economists

8、make assumptions in order to make the world easier to understand.u The art in scientific thinking is deciding which assumptions to make.u Economists use different assumptions to answer different questions.Harcourt, Inc. items and derived items copyright 2001 by Harcourt, Inc.假设的作用假设的作用u 为了使这个世界更容易理解

9、，经济学家为了使这个世界更容易理解，经济学家做一些假设。做一些假设。u 科学思考的艺术就是决定作出什么样的科学思考的艺术就是决定作出什么样的假设。假设。u 经济学家利用不同的假设来回答不同的经济学家利用不同的假设来回答不同的问题。问题。Harcourt, Inc. items and derived items copyright 2001 by Harcourt, Inc.The Economic Way of ThinkinguIncludes developing abstract models from theories and the analysis of the models.u

10、Uses two approaches:uDescriptive (reporting facts, etc.)uAnalytical (abstract reasoning)Harcourt, Inc. items and derived items copyright 2001 by Harcourt, Inc.经济学思考方法经济学思考方法u利用理论建立抽象的模型，然后进利用理论建立抽象的模型，然后进一步分析模型。一步分析模型。u利用两种方法利用两种方法:u描述性的方法描述性的方法 (报告实情等)u分析性的方法分析性的方法 (抽象推理)Harcourt, Inc. items and de

11、rived items copyright 2001 by Harcourt, Inc.Economic Modelsu Economists use models to simplify reality in order to improve our understanding of the worldu Two of the most basic economic models include:uThe Circular Flow ModeluThe Production Possibilities FrontierHarcourt, Inc. items and derived item

12、s copyright 2001 by Harcourt, Inc.经济模型经济模型u 经济学家利用模型来简化真实世界，使我经济学家利用模型来简化真实世界，使我们更好地理解这个世界。们更好地理解这个世界。u 两个最基本的经济学模型是：两个最基本的经济学模型是：u循环流向图循环流向图u生产可能性边界生产可能性边界Harcourt, Inc. items and derived items copyright 2001 by Harcourt, Inc.The Circular-Flow Model经济循环流向图经济循环流向图The circular-flow model is a simple

13、way to visually show the economic transactions that occur between households and firms in the economy.循环流向图循环流向图一个直观地说明一个一个直观地说明一个经济体内家庭和企业之间的经济交易经济体内家庭和企业之间的经济交易行为的简单方式。行为的简单方式。Harcourt, Inc. items and derived items copyright 2001 by Harcourt, Inc.The Circular-Flow DiagramFirmsHouseholdsMarket for

14、Factors of ProductionMarket for Goods and ServicesSpendingRevenueWages, rent, and profitIncomeGoods & Services soldGoods & Services boughtLabor, land, and capitalInputs for productionHarcourt, Inc. items and derived items copyright 2001 by Harcourt, Inc.经济循环图经济循环图企业企业家庭家庭生产要素生产要素市场市场物品与劳务物品与

15、劳务市场市场支出支出收入收入工资、租金工资、租金和利润和利润收入收入销售商品销售商品和服务和服务购买商品购买商品和服务和服务劳动、土地劳动、土地和资本和资本生产投入生产投入Figure 1 The Circular FlowCopyright 2004 South-WesternSpendingGoods andservicesboughtRevenueGoodsand servicessoldLabor, land,and capitalIncome = Flow of inputs and outputs = Flow of dollarsFactors ofproductionWages

16、, rent,and profit FIRMSProduce and sellgoods and servicesHire and use factorsof production Buy and consumegoods and servicesOwn and sell factorsof productionHOUSEHOLDS Households sellFirms buyMARKETSFORFACTORS OF PRODUCTION Firms sellHouseholds buyMARKETSFORGOODS AND SERVICESHarcourt, Inc. items and

17、 derived items copyright 2001 by Harcourt, Inc.The Circular-Flow DiagramHouseholdsu Buy and consume goods and servicesu Own and sell factors of productionFirmsu Produce and sell goods and servicesu Hire and use factors of productionHarcourt, Inc. items and derived items copyright 2001 by Harcourt, I

18、nc.经济循环流向图经济循环流向图家庭家庭u 购买并消费物品与劳务购买并消费物品与劳务u 拥有并出售所有生产要素拥有并出售所有生产要素企业企业u 生产并出售物品与劳务生产并出售物品与劳务u 雇佣并使用生产要素雇佣并使用生产要素Harcourt, Inc. items and derived items copyright 2001 by Harcourt, Inc.The Circular-Flow DiagramMarkets for Factors of Productionu Households sellu Firms buyMarkets for Goods & Servic

19、esu Firms sellu Households buyHarcourt, Inc. items and derived items copyright 2001 by Harcourt, Inc.经济循环图经济循环图生产要素市场生产要素市场u 家庭出售家庭出售u 企业购买企业购买物品与劳务市场物品与劳务市场u 企业出售企业出售u 家庭购买家庭购买Harcourt, Inc. items and derived items copyright 2001 by Harcourt, Inc.The Circular-Flow Diagram经济循环图经济循环图Factors of Produc

20、tion 生产要素生产要素u Inputs used to produce goods and services 用于生产物品与劳务的投入用于生产物品与劳务的投入u Land, labor, and capital 土地、劳动和资本土地、劳动和资本Harcourt, Inc. items and derived items copyright 2001 by Harcourt, Inc.The Production Possibilities FrontierThe production possibilities frontier is a graph showing the various

21、 combinations of output that the economy can possibly produce given the available factors of production and technology.Harcourt, Inc. items and derived items copyright 2001 by Harcourt, Inc.生产可能性边界生产可能性边界生产可能性边界生产可能性边界 表示一个经济在表示一个经济在可得到的生产要素与生产技术既定时可得到的生产要素与生产技术既定时所能生产的产量的各种组合的图形。所能生产的产量的各种组合的图形。 Ha

22、rcourt, Inc. items and derived items copyright 2001 by Harcourt, Inc.The Production Possibilities Frontier生产可能性边界生产可能性边界Quantity ofComputersProducedQuantity ofCars Produced3,0001,0002,0002,200A70060030001,000BCDProductionpossibilitiesfrontier电脑产量电脑产量汽车产量汽车产量生产生产可能性边界可能性边界Harcourt, Inc. items and der

23、ived items copyright 2001 by Harcourt, Inc.Concepts Illustrated by the Production Possibilities FrontieruEfficiencyuTradeoffsuOpportunity CostuEconomic GrowthHarcourt, Inc. items and derived items copyright 2001 by Harcourt, Inc.生产可能性边界阐明的概念生产可能性边界阐明的概念u效率效率u权衡取舍权衡取舍u机会成本机会成本u经济增长经济增长Harcourt, Inc.

24、items and derived items copyright 2001 by Harcourt, Inc.4,000The Production Possibilities FrontierQuantity of ComputersProducedQuantity ofCars Produced3,0002,000A70001,000E2,100750An outward shift in the production possibilities frontierHarcourt, Inc. items and derived items copyright 2001 by Harcou

25、rt, Inc.4,000生产可能性边界生产可能性边界计算机产量计算机产量汽车产量汽车产量3,0002,000A70001,000E2,100750生产可能性边界生产可能性边界向外移动向外移动Harcourt, Inc. items and derived items copyright 2001 by Harcourt, Inc.Microeconomics and MacroeconomicsuMicroeconomics focuses on the individual parts of the economy.uHow households and firms make decisi

26、ons and how they interact in specific marketsuMacroeconomics looks at the economy as a whole.uHow the markets, as a whole, interact at the national level.Harcourt, Inc. items and derived items copyright 2001 by Harcourt, Inc.微观经济学与宏观经济学微观经济学与宏观经济学u微观经济学微观经济学 的研究对象是经济中的个体的研究对象是经济中的个体。u家庭和企业如何作出决策，以及他

27、们如何在家庭和企业如何作出决策，以及他们如何在特定市场上相互交易。特定市场上相互交易。u宏观经济学宏观经济学 研究经济总体现象。研究经济总体现象。u从总体上看，各种市场在国家水平上如何相从总体上看，各种市场在国家水平上如何相互影响。互影响。Harcourt, Inc. items and derived items copyright 2001 by Harcourt, Inc.Two Roles of Economists经济学家的两个角色经济学家的两个角色uWhen they are trying to explain the world, they are scientists. 当他们

28、努力去解释世界时，他们是科学家。当他们努力去解释世界时，他们是科学家。uWhen they are trying to change the world, they are policymakers. 当他们想要改变世界时，他们是政策顾问。当他们想要改变世界时，他们是政策顾问。Harcourt, Inc. items and derived items copyright 2001 by Harcourt, Inc.Positive versus Normative AnalysisuPositive statements are statements that describe the wo

29、rld as it is.uCalled descriptive analysisuNormative statements are statements about how the world should be.uCalled prescriptive analysisHarcourt, Inc. items and derived items copyright 2001 by Harcourt, Inc.实证分析与规范分析实证分析与规范分析u实证表述实证表述 是企图描述世界是什么的是企图描述世界是什么的观点。观点。u被称为描述性分析。被称为描述性分析。u规范表述规范表述 是企图描述世界

30、应该如何是企图描述世界应该如何运行的观点。运行的观点。u被称为命令性分析。被称为命令性分析。Harcourt, Inc. items and derived items copyright 2001 by Harcourt, Inc.?Positive or Normative Statements?实证性还是规范性表述？实证性还是规范性表述？An increase in the minimum wage will cause a decrease in employment among the least-skilled.提高最低工资水平会导致最低技能提高最低工资水平会导致最低技能工人的就业

31、减少。工人的就业减少。Positive 实证性实证性Harcourt, Inc. items and derived items copyright 2001 by Harcourt, Inc.?Positive or Normative Statements?实证性还是规范性表述？实证性还是规范性表述？Higher federal budget deficits will cause interest rates to increase.较高的联邦赤字水平会导致利率上升。较高的联邦赤字水平会导致利率上升。Positive 实证性实证性Harcourt, Inc. items and deri

32、ved items copyright 2001 by Harcourt, Inc.?Positive or Normative Statements?实证性还是规范性表述？实证性还是规范性表述？The income gains from a higher minimum wage are worth more than any slight reductions in employment.提高最低工资水平得到的利益比由此提高最低工资水平得到的利益比由此带来的稍微的就业减少造成的损失大带来的稍微的就业减少造成的损失大Positive 规范性规范性Harcourt, Inc. items an

33、d derived items copyright 2001 by Harcourt, Inc.?Positive or Normative Statements?实证性还是规范性表述？实证性还是规范性表述？State governments should be allowed to collect from tobacco companies the costs of treating smoking-related illnesses among the poor.应该允许州政府向烟草公司收取费用，用于治应该允许州政府向烟草公司收取费用，用于治疗穷人当中与吸烟有关的疾病的费用。疗穷人当中与

34、吸烟有关的疾病的费用。Positive 规范性规范性Harcourt, Inc. items and derived items copyright 2001 by Harcourt, Inc.Economists in Washington . . . . . serve as advisers in the policymaking process of the three branches of government:uLegislativeuExecutiveuJudicialHarcourt, Inc. items and derived items copyright 2001 b

35、y Harcourt, Inc.华盛顿的经济学家华盛顿的经济学家 . . . . .在以下三个政府部门的政策在以下三个政府部门的政策制定过程中充当顾问：制定过程中充当顾问：u立法立法u行政行政u司法司法Harcourt, Inc. items and derived items copyright 2001 by Harcourt, Inc.Economists in WashingtonnSome government agencies that collect economic data and make economic policy:Department of Commerce htt

36、p:/Bureau of Labor Statistics Congressional Budget Office Federal Reserve Board Harcourt, Inc. items and derived items copyright 2001 by Harcourt, Inc.华盛顿华盛顿的经济学家的经济学家n一些一些收集收集经济数据并制定经济政策的政府部经济数据并制定经济政策的政府部门门:商务部商务部 http:/merce.g

37、ov劳工统计局劳工统计局 国会国会预算办公室预算办公室 联邦联邦储备委员会储备委员会 Harcourt, Inc. items and derived items copyright 2001 by Harcourt, Inc.Why Economists Disagree为什么经济学家意见分歧为什么经济学家意见分歧uThey may disagree on theories about how the world works. 对关于世界如何运行的理论的正确性看法不同。

38、对关于世界如何运行的理论的正确性看法不同。uThey may hold different values and, thus, different normative views. 他们可能有不同的价值观，因此就有不同的规范性他们可能有不同的价值观，因此就有不同的规范性观点。观点。Table 2 Ten Propositions about Which Most Economists AgreeHarcourt, Inc. items and derived items copyright 2001 by Harcourt, Inc.大多数经济学家一直同意的大多数经济学家一直同意的10个主张个

39、主张主张以及经济学家同意的百分比主张以及经济学家同意的百分比1. 租金上限减少了可得到的住房数量和质量。（租金上限减少了可得到的住房数量和质量。（93）2. 关税和进口配额通常降低了普遍的经济福利。（关税和进口配额通常降低了普遍的经济福利。（93）3. 有伸缩性和浮动性的汇率提供了一种有效的国际货币协定。（有伸缩性和浮动性的汇率提供了一种有效的国际货币协定。（90）4. 财政政策财政政策 例如，减税和（或）增加政府支出例如，减税和（或）增加政府支出 对低于充分就业的经济有重对低于充分就业的经济有重要的刺激效应。（要的刺激效应。（90）5. 如果要平衡联邦预算，应该在经济周期中而不是每年中来实现

40、。（如果要平衡联邦预算，应该在经济周期中而不是每年中来实现。（85）6. 现金转移支付使领取者福利的增加大于等量现金的实物转移支付。（现金转移支付使领取者福利的增加大于等量现金的实物转移支付。（84）7. 巨额联邦预算赤字对经济有不利影响。（巨额联邦预算赤字对经济有不利影响。（83）8. 最低工资增加了年轻人和不熟练工人中的失业。（最低工资增加了年轻人和不熟练工人中的失业。（79）9. 政府应该按政府应该按“负所得税负所得税”的思路重建福利制度。（的思路重建福利制度。（79）10. 排污税和可交易的污染许可证作为控制污染的方法优于实行污染上限。排污税和可交易的污染许可证作为控制污染的方法优于实

41、行污染上限。（78）Harcourt, Inc. items and derived items copyright 2001 by Harcourt, Inc.SummaryuEconomists try to address their subjects with a scientists objectivity.uThey make appropriate assumptions and build simplified models in order to understand the world around them.uTwo simple economic models are

42、the circular-flow diagram and the production possibilities frontier.Harcourt, Inc. items and derived items copyright 2001 by Harcourt, Inc.小结小结u经济学家经济学家像科学家一样客观地来像科学家一样客观地来研究他们的学科研究他们的学科。u为了理解周围的世界，经济学家进行适当为了理解周围的世界，经济学家进行适当的假设并建立简单的模型。的假设并建立简单的模型。u两个两个简单的经济模型是经济循环图和生产简单的经济模型是经济循环图和生产可能性边界。可能性边界。Har

43、court, Inc. items and derived items copyright 2001 by Harcourt, Inc.SummaryuThe field of economics is divided into two subfields: microeconomics and macroeconomics.uMicroeconomists study decisionmaking by households and firms in the marketplace.u Macroeconomists study the forces and trends that affe

44、ct the economy as a whole.Harcourt, Inc. items and derived items copyright 2001 by Harcourt, Inc.小结小结u经济学分为两个领域：微观经济学和宏经济学分为两个领域：微观经济学和宏观经济学。观经济学。u微观经济学家研究市场中的家庭和企业微观经济学家研究市场中的家庭和企业所作的决策。所作的决策。u宏观经济学家研究影响整体经济的力量宏观经济学家研究影响整体经济的力量和趋势。和趋势。Harcourt, Inc. items and derived items copyright 2001 by Harcour

45、t, Inc.SummaryuEconomics relies on both positive and normative analysis.uPositive statements is an assertion about how the world “is”。unormative statements is an assertion about how the world “ought to be”.uWhen economists make normative statements, they are acting more as policy advisors than scien

46、tists.Harcourt, Inc. items and derived items copyright 2001 by Harcourt, Inc.小结小结u经济学依赖实证分析和规范分析。经济学依赖实证分析和规范分析。u实证表述是关于世界实证表述是关于世界是什么是什么的论断。的论断。u规范表述是关于世界规范表述是关于世界应该是什么应该是什么的论的论断。断。u当经济学家做规范性表述时，与其说当经济学家做规范性表述时，与其说其是科学家，不如说其是政策顾问。其是科学家，不如说其是政策顾问。Harcourt, Inc. items and derived items copyright 2001

47、 by Harcourt, Inc.SummaryuEconomists who advise policymakers may offer conflicting advice either because of differences in scientific judgments or because of differences in valuesuAt other times, economists are united in the advice they offer, but policymakers may choose to ignore it.Harcourt, Inc.

48、items and derived items copyright 2001 by Harcourt, Inc.小结小结u给给政策制定者提供建议的经济学家提出政策制定者提供建议的经济学家提出相互冲突的建议，这是因为科学判断的相互冲突的建议，这是因为科学判断的不同，或者是价值观的不同。不同，或者是价值观的不同。u在在其他一些时候，经济学家在他们提供其他一些时候，经济学家在他们提供的建议上相互一直，但是政策制订者可的建议上相互一直，但是政策制订者可能选择不采纳。能选择不采纳。Harcourt, Inc. items and derived items copyright 2001 by Harco

49、urt, Inc.Graphical ReviewHarcourt, Inc. items and derived items copyright 2001 by Harcourt, Inc.Government (41%)Government (41%)Other (4%)Other (4%)Individuals (23%)Individuals (23%)Private Insurers (32%)Private Insurers (32%)( (a) Pie Charta) Pie ChartProductivity Index (farmProductivity Index (far

50、moutput per hour of labor,output per hour of labor,1977 = 100)1977 = 100)10010080806060404020200 0160160120120140140( (c) Time-Series Graphc) Time-Series Graph19501950196019601970197019801980199019901996 1996 Value Value (in(inbillions of dollars)billions of dollars)GeneralGeneralElectricElectric($126 ($1