1、Principles of Economics Third Edition by N. Gregory Mankiw经济学原理（第三版）,1 INTRODUCTION 导言,Ten Principles of Economics 经济学十大原理,Chapter 1,Economy. . . 经济,. . . The word economy comes from a Greek word for “one who manages a household.”经济一词来源于希腊语，意思是“管理家庭的人”。,A household and an economy face many decisions
2、: 一个家庭和经济体面临很多决策：,Who will work?谁去工作？ What goods and how many of them should be produced?应该生产什么物品？应该生产多少？,A household and an economy face many decisions: 一个家庭和经济体面临很多决策：,What resources should be used in production?应该用什么资源生产？ At what price should the goods be sold?物品的销售价格应该是多少？,Society and Scarce Res
3、ources: 社会和稀缺资源：,The management of societys resources is important because resources are scarce. 因为资源是稀缺的，所以社会资源的管理就很重要。,Scarcity . . . 稀缺,. . . means that society has limited resources and therefore cannot produce all the goods and services people wish to have. 意思是说，社会拥有有限的资源，不能生产出人们想要的所有物品与劳务。,Eco
4、nomics 经济学,Economics is the study of how society manages its scarce resources. 经济学研究社会如何管理自己的稀缺资源的学科。,Economists study. . . 经济学家研究,How people make decisions. 人们如何作出决策 How people interact with each other. 人们如何与他人相互交易 The forces and trends that affect the economy as a whole.影响整体经济的力量和趋势,Ten Principles
5、 of Economics,People face tradeoffs. The cost of something is what you give up to get it. Rational people think at the margin. People respond to incentives.,How People Make Decisions,经济学十大原理,人们面临权衡取舍 某东西的成本就是为得到它所放弃的东西 理性人考虑边际量 人们会对激励作出反应,人们如何作出决策,Ten Principles of Economics,Trade can make everyone
6、better off. Markets are usually a good way to organize economic activity. Governments can sometimes improve economic outcomes.,How People Interact with each other,经济学十大原理,贸易可以使每个人状况更好。 市场通常是组织经济活动的一种好方法。 政府有时能改善市场经济效果。,人们如何与他人相互交易,Ten Principles of Economics,The standard of living depends on a count
7、rys production. Prices rise when the government prints too much money. Society faces a short-run tradeoff between inflation and unemployment.,The forces and trends that affect how the economy as a whole works,经济学十大原理,一国的生活水平取决于它生产物品与劳务的能力。 当政府发行了过多货币时，物价上升。 社会面临通货膨胀与失业之间的短期权衡取舍。,影响整体经济如何运行的力量和趋势,Peo
8、ple face tradeoffs. 人们面临权衡取舍,“There is no such thing as a free lunch!” 天下没有免费的午餐,1. People face tradeoffs.,To get one thing, we usually have to give up another thing.Guns v. butterFood v. clothingLeisure time v. workEfficiency v. equity,Making decisions requires trading off one goal against another.
9、,1.人们面临权衡取舍,为了得到我们喜爱的一件东西，我们通常不得不放弃另一件喜爱的东西。 大炮 vs.黄油 食物 vs. 衣服 休闲 vs. 工作 效率 vs. 平等,作决策时需要在两个目标之间权衡取舍,1. People face tradeoffs.,Efficiency means society gets the most that it can from its scarce resources. Equity means the benefits of those resources are distributed fairly among the members of socie
10、ty.,Efficiency v. Equity,1.人们面临权衡取舍,效率 社会能从其稀缺资源中得到最多东西的特性。 平等 社会资源的经济成果在社会成员中公平分配的特性。,效率与平等,2. The cost of something is what you give up to get it.,Decisions require comparing costs and benefits of alternatives. Whether to go to college or to work? Whether to study or go out on a date? Whether to g
11、o to class or sleep in?,2.某东西的成本就是为得到它 所放弃的东西,作出决策时需要比较可供选择的行动方案的成本与收益上大学还是去工作? 学习还是出去约会? 去上课还是睡觉?,2. The cost of something is what you give up to get it 某东西的成本就是为得到它所放弃的东西,The opportunity cost of an item is what you give up to obtain that item. 机会成本为了得到某种东西所必需放弃的东西。,2. The Cost of Something Is What
12、 You Give Up to Get It.,LA Laker basketball star Kobe Bryant chose to skip college and go straight from high school to the pros where he has earned millions of dollars.,当预期在四年之内赚得上千万美元时，高中篮球明星科比.布赖恩特（Kobe Bryant ）决定不读大学而直接进入职业篮球联盟（ NBA ）。,2.某东西的成本就是为得到它 所放弃的东西,3. Rational people think at the margin
13、理性人考虑边际量,Marginal changes are small, incremental adjustments to an existing plan of action. 边际变动对当前行动计划微小的增量调整。,People make decisions by comparing costs and benefits at the margin. 人们作决策时需要比较边际成本和边际利益。,4. People respond to incentives.,Marginal changes in costs or benefits motivate people to respond.
14、 The decision to choose one alternative over another occurs when that alternatives marginal benefits exceed its marginal costs!,4. 人们会对激励作出反应,成本或收益的边际改变会激励人们作出反应。 当一个方案的边际收益大于边际成本时，人们选择这个方案，而不去选择别的。,5. Trade can make everyone better off.,People gain from their ability to trade with one another. Comp
15、etition results in gains from trading. Trade allows people to specialize in what they do best.,5. 贸易能使每个人状况变好,人们可以从与他人相互交易的能力中获益。 竞争可以使人们从贸易中获益。 贸易可以让人们从事他们最专长的工作。,6. Markets are usually a good way to organize economic activity.,A market economy is an economy that allocates resources through the dec
16、entralized decisions of many firms and households as they interact in markets for goods and services. households decide what to buy and who to work for. Firms decide who to hire and what to produce.,6. 市场通常是组织经济活动的一种好方法,市场经济当许多企业和家庭在物品与劳务市场上相互交易时通过他们的分散决策配置资源的经济。 家庭决定购买什么和为谁工作。 企业决定雇佣谁和生产什么。,6. Mark
17、ets are usually a good way to organize economic activity.,Adam Smith made the observation that households and firms interacting in markets act as if guided by an “invisible hand.”,6. 市场通常是组织经济活动的一种好方法,亚当.斯密提出了全部经济学中最有名的观察结果：家庭和企业在市场上相互交易，他们仿佛被一只“看不见的手”所指引，导致了合意的市场结果。,6. Markets are usually a good wa
18、y to organize economic activity.,Because households and firms look at prices when deciding what to buy and sell, they unknowingly take into account the social costs of their actions. As a result, prices guide decision makers to reach outcomes that tend to maximize the welfare of society as a whole.,
19、6. 市场通常是组织经济活动的一种好方法,由于家庭和企业在决定购买和出售什么时关注价格，所以他们就不知不觉地考虑到了他们的行为的社会收益与成本。 结果是，价格指引这些个别决策者在大多数情况下实现了整个社会福利最大化的结果。,7. Governments can sometimes improve market outcomes 政府有时能改善市场结果,Market failure occurs when the market fails to allocate resources efficiently. 市场失灵市场本身不能有效配置资源的情况。,7. Governments can some
20、times improve market outcomes. 政府有时能改善市场结果,When the market fails (breaks down) government can intervene to promote efficiency and equity. 当市场失灵时，政府可以对市场进行干预以促进效率和平等。,7. Governments can sometimes improve market outcomes 政府有时能改善市场结果,Market failure may be caused by an externality, which is the impact o
21、f one person or firms actions on the well-being of a bystander. 市场失灵的一个可能原因是外部性。外部性是一个人的行为对旁观者福利的影响。,7. Governments can sometimes improve market outcomes.,Market failure may also be caused by market power, which is the ability of a single person or firm to unduly influence market prices.,7.政府有时能改善市场
22、结果,市场失灵的另一个可能原因是市场势力。 市场势力是指一个人或一个企业不适当地影响市场价格的能力。,8. The standard of living depends on a countrys production.,Standard of living may be measured in different ways: By comparing personal incomes. By comparing the total market value of a nations production.,8. 一国的生活水平取决于它生产物品与劳务的能力,生活水平 可以用不同的方式衡量: 比
23、较人均收入。 比较一个国家产出的总的市场价值。,8. The standard of living depends on a countrys production.,Almost all variations in living standards are explained by differences in countries productivities.,8. 一国的生活水平取决于它生产物品与劳务的能力,几乎所有生活水平的差异都可以归因于各国生产率的差别。,8. The standard of living depends on a countrys production.,Prod
24、uctivity is the amount of goods and services produced from each hour of a workers time.,Higher productivity Higher standard of living,8. 一国的生活水平取决于它生产物品与劳务的能力,生产率 是指一个工人一小时所生产的物品与劳务量。,高生产率 高生活水平,9. Prices rise when the government prints too much money.,Inflation is an increase in the overall level o
25、f prices in the economy. One cause of inflation is the growth in the quantity of money. When the government creates large quantities of money, the value of the money falls.,9. 当政府发行了过多货币时，物价上升,通货膨胀 是指经济中物价总水平的上升。 通货膨胀的一个原因是货币量的增长。 当一个政府创造了大量本国货币时，货币的价值就下降。,10. Society faces a short-run tradeoff betw
26、een inflation and unemployment.,The Phillips Curve illustrates the tradeoff between inflation and unemployment: Inflation Unemployment Its a short-run tradeoff!,10. 社会面临通货膨胀与失业之间的短期权衡取舍,菲利普斯曲线 说明了通货膨胀与失业之间的短期权衡取舍 : 通货膨胀 失业 这是短期权衡取舍。,Summary 内容提要,When individuals make decisions, they face tradeoffs a
27、mong alternative goals.当个人决策时，在不同的目标之间面临权衡取舍。 The cost of any action is measured in terms of foregone opportunities. 任何一种行为的成本用所放弃的机会来衡量。,Summary 内容提要,Rational people make decisions by comparing marginal costs and marginal benefits. 理性人通过比较边际成本与边际收益作出决策 。 People change their behavior in response to
28、the incentives they face.人们对所面临激励的反映就是改变他们的行为。,Summary 内容提要,People can benefit by trading with each other. 贸易可以是互利的。 Markets are usually a good way of coordinating trades.市场通常是协调贸易的一种好方法。 Government can potentially improve market outcomes if there is some market failure or if the market outcome is i
29、nequitable.如果存在市场失灵或者市场结果不平等时，政府有可能改善市场结果。,Summary,Productivity is the ultimate source of living standards. Money growth is the ultimate source of inflation. Society faces a short-run tradeoff between inflation and unemployment.,内容提要,生产率是生活水平高低的最终根源。 货币增长是通货膨胀的最终根源。 社会面临着通货膨胀与失业之间的短期权衡取舍。,Thinking L
30、ike an Economist 像经济学家一样思考,Chapter 2,Every field of study has its own terminology,Mathematics,Psychology,Law,每个研究领域都有自己的语言,数学,心理学,法律,Every field of study has its own terminology,Economics,Supply,Demand,Elasticity,Consumer Surplus,Comparative advantage,Opportunity cost,Deadweight loss,每个研究领域都有自己的语言,经
31、济学,供给,需求,弹性,消费者剩余,比较优势,机会成本,无谓损失,Economics trains you to. . . .,Think in terms of alternatives. Evaluate the cost of individual and social choices. Examine and understand how certain events and issues are related.,经济学训练你. . . .,从不同的角度思考问题。 评估个人和社会选择的成本。 检查和理解一些事件和问题是如何相互关联的。,The Economist as a Scien
32、tist 作为科学家的经济学家,The economic way of thinking . . .经济学思考方法 Involves thinking analytically and objectively.客观地分析与思考。 Makes use of the scientific method.利用科学的方法。,The Scientific Method,Uses abstract models to help explain how a complex, real world operates. Develops theories, collects, and analyzes data
33、 to prove the theories.,Observation, Theory and More Observation!,科学方法,利用抽象的模型帮助解释复杂的真实世界如何运行。 形成理论，收集并分析数据来验证理论。,观察, 理论 ，更多的观察,The Role of Assumptions,Economists make assumptions in order to make the world easier to understand.The art in scientific thinking is deciding which assumptions to make.Eco
34、nomists use different assumptions to answer different questions.,假设的作用,为了使这个世界更容易理解，经济学家做一些假设。科学思考的艺术就是决定作出什么样的假设。经济学家利用不同的假设来回答不同的问题。,The Economic Way of Thinking,Includes developing abstract models from theories and the analysis of the models. Uses two approaches:,Descriptive (reporting facts, etc
35、.) Analytical (abstract reasoning),经济学思考方法,利用理论建立抽象的模型，然后进一步分析模型。 利用两种方法:,描述性的方法 (报告实情等) 分析性的方法 (抽象推理),Economic Models,Economists use models to simplify reality in order to improve our understanding of the worldTwo of the most basic economic models include:,The Circular Flow Model,The Production Pos
36、sibilities Frontier,经济模型,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。两个最基本的经济学模型是：,循环流向图,生产可能性边界,The Circular-Flow Model 经济循环流向图,The circular-flow model is a simple way to visually show the economic transactions that occur between households and firms in the economy. 循环流向图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行为的简单方式。,The Circ
37、ular-Flow Diagram,Firms,Households,Market for Factors of Production,Market for Goods and Services,经济循环图,企业,家庭,生产要素 市场,物品与劳务 市场,Figure 1 The Circular Flow,Copyright 2004 South-Western,Spending,Revenue,Income,= Flow of inputs,and outputs,= Flow of dollars,The Circular-Flow Diagram,HouseholdsBuy and co
38、nsume goods and servicesOwn and sell factors of production,FirmsProduce and sell goods and servicesHire and use factors of production,经济循环流向图,家庭购买并消费物品与劳务拥有并出售所有生产要素,企业生产并出售物品与劳务雇佣并使用生产要素,The Circular-Flow Diagram,Markets for Factors of ProductionHouseholds sellFirms buy,Markets for Goods & Services
39、Firms sellHouseholds buy,经济循环图,生产要素市场家庭出售企业购买,物品与劳务市场企业出售家庭购买,The Circular-Flow Diagram 经济循环图,Factors of Production 生产要素Inputs used to produce goods and services用于生产物品与劳务的投入Land, labor, and capital土地、劳动和资本,The Production Possibilities Frontier,The production possibilities frontier is a graph showing
40、 the various combinations of output that the economy can possibly produce given the available factors of production and technology.,生产可能性边界,生产可能性边界 表示一个经济在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。,The Production Possibilities Frontier 生产可能性边界,Quantity of Computers Produced,Quantity of Cars Produced,3,000,1,0
41、00,2,000,2,200,A,700,600,300,0,1,000,B,C,D,Production,possibilities,frontier,电脑产量,汽车产量,生产 可能性边界,Concepts Illustrated by the Production Possibilities Frontier,Efficiency Tradeoffs Opportunity Cost Economic Growth,生产可能性边界阐明的概念,效率 权衡取舍 机会成本 经济增长,The Production Possibilities Frontier,Quantity of Compute
42、rs Produced,Quantity of Cars Produced,3,000,2,000,A,700,0,1,000,An outward shift in the production possibilities frontier,生产可能性边界,计算机产量,汽车产量,3,000,2,000,A,700,0,1,000,生产可能性边界 向外移动,Microeconomics and Macroeconomics,Microeconomics focuses on the individual parts of the economy. How households and firm
43、s make decisions and how they interact in specific markets Macroeconomics looks at the economy as a whole. How the markets, as a whole, interact at the national level.,微观经济学与宏观经济学,微观经济学 的研究对象是经济中的个体。 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。 宏观经济学 研究经济总体现象。 从总体上看，各种市场在国家水平上如何相互影响。,Two Roles of Economists 经济学家的两
44、个角色,When they are trying to explain the world, they are scientists.当他们努力去解释世界时，他们是科学家。 When 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。,Positive versus Normative Analysis,Positive statements are statements that describe the world as it is. Called descriptive analys
45、is Normative statements are statements about how the world should be. Called prescriptive analysis,实证分析与规范分析,实证表述 是企图描述世界是什么的观点。 被称为描述性分析。 规范表述 是企图描述世界应该如何运行的观点。 被称为命令性分析。,?,?,Positive or Normative Statements? 实证性还是规范性表述？,An increase in the minimum wage will cause a decrease in employment among the
46、least-skilled. 提高最低工资水平会导致最低技能工人的就业减少。Positive 实证性,?,?,?,Positive or Normative Statements? 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。Positive 实证性,?,?,?,?,Positive or Normative Statements? 实证性还是规范性表述？,The income gains from a higher minimum wage
47、 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带来的稍微的就业减少造成的损失大Positive 规范性,?,?,?,Positive or Normative Statements? 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
48、司收取费用，用于治疗穷人当中与吸烟有关的疾病的费用。Positive 规范性,Economists in Washington . . .,. . . serve as advisers in the policymaking process of the three branches of government: Legislative Executive Judicial,华盛顿的经济学家 . . .,. . .在以下三个政府部门的政策制定过程中充当顾问： 立法 行政 司法,Economists in Washington,Some government agencies that col
49、lect economic data and make economic policy: Department of Commerce http:/merce.gov Bureau of Labor Statistics http:/www.bls.gov Congressional Budget Office http:/www.cbo.gov Federal Reserve Board http:/www.federalreserve.gov,华盛顿的经济学家,一些收集经济数据并制定经济政策的政府部门: 商务部 http:/merce.gov 劳工统计局 http:/www.bls.gov 国会预算办公室 http:/www.cbo.gov 联邦储备委员会 http:/www.federalreserve.gov,Why Economists Disagree 为什么经济学家意见分歧,They 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。 They 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观点。,
