教学配套课件：克鲁格曼经济学原理(英文)

1、CHAPTER 1First Principles2What you will learn in this chapter:How individuals make choices:ScarcityOpportunity costTrade-offsMarginal analysisHow individual choices interact:TradeGains from trade Specialization Equilibrium Efficiency and equity3How Individuals Make Choices:Basic principles behind th

2、e individual choices: 1. Resources are scarce. 2. The real cost of something is what you must give up to get it Opportunity costIt is all about what you have to forgo to obtain your choice.4How Individuals Make Choices:3. “How much?” is a decision at the margin. Trade-offs Marginal decisions and mar

3、ginal analysis4. People usually take advantage of opportunities to make themselves better off.Incentives5Interaction: How Economies WorkPrinciples behind the interaction of individual choices:1. There are gains from trade. Specialization Trade and gains from trade2. Markets move toward equilibrium.3

4、. Resources should be used as efficiently as possible to achieve societys goals. Efficiency Equity6Interaction: How Economies Work4. Markets usually lead to efficiency. Exceptions: Market failure5. When markets dont achieve efficiency, government intervention can improve societys welfare.7The End of

5、 Chapter 1coming attraction:Chapter 2: Economic Models: Trade-offs and TradeCHAPTER 2Economic Models: Trade-offs and Trade9What you will learn in this chapter:Why models? simplified representations of realityproduction possibility frontiercomparative advantagecircular-flow diagramPositive economics

6、vs. normative economicsWhen economists agree and why they sometimes disagree.10Models in Economics:A model is a simplified representation of a real situation that is used to better understand real-life situations.The production possibility frontier (PPF) illustrates the trade-offs facing an economy

7、that produces only two goods. It shows the maximum quantity of one good that can be produced for any given production of the other.11Toms Trade-offs: The Production Possibility Frontier12Increasing Opportunity Cost13Economic GrowthEconomic growth results in an outward shift of the PPF because produc

8、tion possibilities are expanded.14Comparative Advantage and Gains from TradeEx.: Tom and Hank15Tom and Hanks Opportunity Costs of Fish and CoconutsToms Opportunity CostHanks Opportunity CostOne fish3/4 coconut2 coconutsOne coconut4/3 fish1/2 fishBoth castaways are better off when they each specializ

9、e in what they are good at and trade. 16Specialize and Trade17Comparative vs. absolute advantageComparative advantage: the opportunity cost of producing the good is lower for that individual than for other people.Absolute advantage: if he or she can do it better than other people. Careful: Dont conf

10、use comparative advantage with absolute advantage!18Comparative Advantage and International Trade Ex.: U.S. vs. Canadian EconomyThe U.S. and Canada can both achieve mutual gains from trade.19Transactions: The Circular-Flow DiagramThe circular-flow diagram is a model that represents the transactions

11、in an economy by flows around a circle.20Circular-Flow of Economic ActivitiesEconomic Agents:HouseholdsFirmsWhere they interact:Markets for goods and servicesMarkets for factors of production21Growth in the U.S. Economy from 1962 to 198822Using Models / Why economist (dis)agree?Positive economicsNor

12、mative economicsA forecast is a simple prediction of the future.There are two main reasons economists disagree: they may disagree about which simplifications to make in a model they may disagree about values23The End of Chapter 2coming attraction:Chapter 3: Supply and DemandCHAPTER 3Supply and Deman

13、d25Supply and DemandCompetitive market The supply and demand modelThe demand curveThe supply curveFactors that cause the demand curve to shift, and factors that cause the supply curve to shiftThe equilibrium priceHow the equilibrium price changes when the supply and demand curves shift 26The Law of

14、Demand Higher price for a good, other things equal, leads people to demand a smaller quantity of the good.27An Increase in Demand 28Movement Along the Demand Curve vs. Shift of the Demand Curve 29Shifts of the Demand Curve 30What causes a demand curve to shift?Changes in the Prices of Related GoodsS

15、ubstitutesComplementsChanges in IncomeNormal GoodsInferior GoodsChanges in TastesChanges in Expectations31The Supply Curve 32A Decrease in Supply 33Movement Along the Supply Curve vs. Shift of the Supply Curve 34Shifts of the Supply Curve 35What causes a supply curve to shift?Changes in Input Prices

16、An input is a good that is used to produce another good. Changes in TechnologyChanges in IncomeChanges in Expectations36Market Equilibrium 37Price Above Its Equilibrium Level Creates a Surplus 38Price Below Its Equilibrium Level Creates a Shortage 39Equilibrium and Shifts of the Demand Curve 40Equil

17、ibrium and Shifts of the Supply Curve 41Simultaneous Shifts of the Demand and Supply Curves 42Effects of the “War on Drugs” 43The End of Chapter 3coming attraction:Chapter 4: The Market Strikes BackCHAPTER 4The Market Strikes Back45Contents of the ChapterPrice controlsPrice ceilingPrice floorQuantit

18、y controlsquotaExcise taxInefficiency46The Market for Apartments in the Absence of Government Controls47The Effects of a Price Ceiling 48Price ceilings often lead to inefficiency in the forms of:49The Market for Butter in the Absence of Government Controls 50The Effects of a Price Floor 51Price floo

19、rs often lead to inefficiency in the forms of:52The Market for Taxi Rides in the Absence of Government Controls 53Effect of a Quota on the Market for Taxi Rides 54Effect of an Excise Tax Levied on the Sales of Taxi Rides55Effect of an Excise Tax Levied on Purchases of Taxi Rides 56The Revenue from a

20、n Excise Tax57Tax incidenceExcess burdenDeadweight lossTax revenueExcise Tax: Key Terms58The End of Chapter 4coming attraction:Chapter 5: ElasticityCHAPTER 5Elasticity60What you will learn in this chapter:Definition of elasticityprice elasticity of demandincome elasticity of demand andprice elastici

21、ty of supplyFactors that influence the size of elasticitiesHow elasticity affects the incidence of a tax, and who bears its burden?61Defining and Measuring ElasticityThe price elasticity of demand is the ratio of the percent change in the quantity demanded to the percent change in the price as we mo

22、ve along the demand curve.62The World Demand for Oil63Using the Midpoint Method to Calculate Elasticities64Some Estimated Price Elasticities of DemandGood Price elasticityInelastic demandEggs 0.1Beef 0.4Stationery0.5Gasoline 0.5Elastic demandHousing 1.2Restaurant meals 2.3Airline travel 2.4Foreign t

23、ravel 4.1Price elasticity of demand 165Interpreting the Price Elasticity of Demand: How Elastic Is Elastic?Two Extreme Cases of Price Elasticity of Demandperfectly inelasticperfectly elastic666768Interpreting the Price Elasticity of Demand: How Elastic Is Elastic?Demand is: elastic if the price elas

24、ticity of demand is greater than 1, inelastic if the price elasticity of demand is less than 1, and unit-elastic if the price elasticity of demand is exactly 1.6970717273Elasticity and Total Revenue A price effect: After a price increase, each unit sold sells at a higher price, which tends to raise

25、revenue. A sales effect: After a price increase, fewer units are sold, which tends to lower revenue.7475Elasticity and Total RevenueIf demand for a good is elastic, an increase in price reduces total revenue. (Sales effect Price effect).If demand for a good is inelastic, a higher price increases tot

26、al revenue. (Price effect Sales effect).If demand for a good is unit-elastic, an increase in price does not change total revenue. (Sales effect = Price effect).76The Price Elasticity of Demand Changes Along the Demand Curve77What Factors Determine the Price Elasticity of Demand?Whether Close Substit

27、utes Are Available Whether the Good Is a Necessity or a Luxury Time 78Other Demand ElasticitiesCross-Price ElasticitySubstitutesComplementsIncome elasticity of demandNormal GoodsInferior Goods79Price Elasticity of SupplyThe price elasticity of supply is a measure of the responsiveness of the quantit

28、y of a good supplied to the price of that good. 808182Factors that Determine the Price Elasticity of SupplyThe Availability of Inputs Time83Elasticity determines tax incidence: An Excise Tax Paid Mainly by Consumers84Elasticity determines tax incidence: An Excise Tax Paid Mainly by Producers85The En

29、d of Chapter 5coming attraction:Chapter 6: Consumer and Producer SurplusCHAPTER 6Consumer and Producer Surplus87What you will learn in this chapter:Consumer SurplusProducer SurplusCost Market FailureHow much benefit do producers and consumers receive from the existence of a market?How is the welfare

30、 of consumers and producers affected by changes in market prices?How are these concepts related to demand and supply curve? 88Individual consumer surplus is the net gain to an individual buyer from the purchase of a good. It is equal to the difference between the buyers willingness to pay and the pr

31、ice paid.Total producer surplus in a market is the sum of the individual producer surpluses of all the sellers of a good.Consumer Surplus and the Demand Curve89The Demand Curve for Used Textbooks9091Consumer SurplusThe total consumer surplus generated by purchases of a good at a given price is equal

32、 to the area below the demand curve but above that price.92A Fall in the Price of Used Textbooks93A Fall in the Market Price Increases Consumer Surplus94Producer Surplus and the Supply CurveA potential sellers cost is the lowest price at which he or she is willing to sell a good.Individual producer

33、surplus is the net gain to a seller from selling a good. It is equal to the difference between the price received and the sellers cost. Total producer surplus in a market is the sum of the individual producer surpluses of all the sellers of a good.95The Supply Curve for Used Textbooks96Producer Surp

34、lus in the Used-Textbook Market97The total producer surplus from sales of a good at a given price is the area above the supply curve but below that price.Producer Surplus98A Rise in Price Increases Producer Surplus99Putting it together: Total Surplus The total surplus generated in a market is the to

35、tal net gain to consumers and producers from trading in the market. It is the sum of the producer and the consumer surplus.The concepts of consumer surplus and producer surplus can help us understand why markets are an effective way to organize economic activity.100Total Surplus101Consumer Surplus,

36、Producer Surplus, Gains from Trade and Efficiency of MarketsBoth consumers and producers are better off because there is a market in this good, i.e. there are gains from trade. The maximum possible total surplus (highest possible gain to society) is achieved at market equilibrium.In the market equil

37、ibrium there is no way to make some people better off without making others worse off markets are efficient.102Reallocating Consumption Lowers Consumer Surplus103Reallocating Sales Lowers Producer Surplus104Changing the Quantity Lowers Total Surplus105The market equilibrium maximizes total surplus b

38、ecause the market performs four important functions:1. It allocates consumption of the good to the potential buyers who value it the most.2. It allocates sales to the potential sellers who most value the right to sell the good.3. It ensures that every consumer who makes a purchase values the good mo

39、re than every seller who makes a sale.4. It ensures that every potential buyer who doesnt make a purchase values the good less than every potential seller who doesnt make a sale.106Applying Consumer and Producer Surplus: The Efficiency Costs of a TaxA tax causes a deadweight loss to society, because

40、 less of the good is produced and consumed than in the absence of the tax. As a result, some mutually beneficial trades between producers and consumers do not take place.107A Tax Reduces Consumer and Producer Surplus108The Deadweight Loss of a Tax109Deadweight Loss and ElasticitiesThe general rule f

41、or economic policy is that other things equal, you want to choose the policy that produces the smallest deadweight loss. But how can we predict the size of the deadweight loss associated with a given policy?For a tax imposed when demand or supply, or both, is inelastic will cause a relatively small

42、decrease in quantity transacted and a small deadweight loss.110111112The End of Chapter 6coming attraction:Chapter 7: Behind the Supply Curve: Inputs and CostsCHAPTER 7Behind the Supply Curve: Inputs and Costs114What you will learn in this chapter:The relationship between quantity of inputs and quan

43、tity of outputWhy production is often subject to diminishing returns to inputsWhat the various forms of a firms costs are and how they generate the firms marginal and average cost curvesWhy a firms costs may differ in the short run versus the long runHow the firms technology of production can genera

44、te economies of scale115The Production FunctionA production function is the relationship between the quantity of inputs a firm uses and the quantity of output it produces.A fixed input is an input whose quantity is fixed and cannot be varied.A variable input is an input whose quantity the firm can v

45、ary.116Inputs and OutputThe long run is the time period in which all inputs can be varied.The short run is the time period in which at least one input is fixed.The total product curve shows how the quantity of output depends on the quantity of the variable input, for a given quantity of the fixed in

46、put.117Production Function and TP Curve for George and Marthas Farm118The marginal product of an input is the additional quantity of output that is produced by using one more unit of that input.Marginal Product of Labor119Diminishing Returns to an InputThere are diminishing returns to an input when

47、an increase in the quantity of that input, holding the levels of all other inputs fixed, leads to a decline in the marginal product of that input.The following marginal product of labor curve illustrates this concept clearly120Marginal Product of Labor Curve121Total Product, Marginal Product, and th

48、e Fixed Input122Total Cost Curve for George and Marthas Farm123From the Production Function to Cost CurvesA fixed cost is a cost that does not depend on the quantity of output produced. It is the cost of the fixed input.A variable cost is a cost that depends on the quantity of output produced. It is

49、 the cost of the variable input.124Total Cost CurveThe total cost of producing a given quantity of output is the sum of the fixed cost and the variable cost of producing that quantity of output. TC=FC + VCThe total cost curve becomes steeper as more output is produced due to diminishing returns.125D

50、efinition of Marginal Cost126Total Cost and Marginal Cost Curves for Bens Boots127Average CostAverage total cost, often referred to simply as average cost, is total cost divided by quantity of output produced.ATC = TC/QAverage fixed cost is the fixed cost per unit of output. AFC = FC/QAverage variab

51、le cost is the variable cost per unit of output. AVC = VC/Q128The average total cost curve at Bens Boots is U-shaped. At low levels of output, average total cost falls because the “spreading effect” of falling average fixed cost dominates the “diminishing returns effect” of rising average variable c

52、ost. At higher levels of output, the opposite is true and average total cost rises.Average Total Cost Curve for Bens Boots129Putting the four curves together: Marginal Cost and Average Cost Curves for Bens Boots130General principles that are always true about a firms marginal and average total cost

53、curves: At the minimum-cost output, average total cost is equal to marginal cost.At output less than the minimum-cost output, marginal cost is less than average total cost and average total cost is falling.And at output greater than the minimum-cost output, marginal cost is greater than average tota

54、l cost and average total cost is rising.131The Relationship Between the Average Total Cost and the Marginal Cost Curves132Marginal cost curves do not always slope upward. The benefits of specialization of labor can lead to increasing returns at first represented by a downward-sloping marginal cost c

55、urve. Once there are enough workers to permit specialization, however, diminishing returns set in.More Realistic Cost Curves133Short-Run versus Long-Run CostsIn the short-run, fixed cost is completely outside the control of a firm. But all inputs are variable in the long-run: fixed cost may also be

56、varied. In the long run a firms fixed cost becomes a variable it can choose.134There is a trade-off between higher fixed cost and lower variable cost for any given output level, and vice versa.But as output goes up, average total cost is lower with the higher amount of fixed cost.Choosing the Level

57、of Fixed Cost for Bens Boots135The long-run average total cost curve shows the relationship between output and average total cost when fixed cost has been chosen to minimize average total cost for each level of output.The Long-Run Average Total Cost Curve136Short-Run and Long-Run Average Total Cost

58、Curves137Economies and Diseconomies of ScaleThere are economies of scale when long-run average total cost declines as output increases.There are diseconomies of scale when long-run average total cost increases as output increases.There are constant returns to scale when long-run average total cost i

59、s constant as output increases.138The End of Chapter 7coming attraction:Chapter 8: Perfect Competition and the Supply CurveCHAPTER 8Perfect Competition and theSupply Curve140What you will learn in this chapter: Perfect competition and the characteristics of a perfectly competitive industry How a pri

60、ce-taking producer determines its profit-maximizing quantity of output Profits and why an unprofitable producer may continue to operate in the short run Short run versus the long run behavior of industries Industry supply curve in the short run and the long run141Perfect CompetitionA price-taking pr