曼昆经济学原理微观部分课件.pptx

1、Harcourt, Inc. items and derived items copyright 2001 by Harcourt, Inc.Supply, Demand, and Government PoliciesuIn a free, unregulated market system, market forces establish equilibrium prices and exchange quantities.uWhile equilibrium conditions may be efficient, it may be true that not everyone is

2、satisfied. uOne of the roles of economists is to use their theories to assist in the development of policies.Harcourt, Inc. items and derived items copyright 2001 by Harcourt, Inc.供给、需求与政府政策供给、需求与政府政策u在一个自由、无管制的市场系统中，市在一个自由、无管制的市场系统中，市场力量实现均衡价格和均衡交易量。场力量实现均衡价格和均衡交易量。u这种均衡结果也许是有效的，但并不是这种均衡结果也许是有效的，但并

3、不是每个人对此都感到满意。每个人对此都感到满意。 u经济学家的作用之一就是利用他们的理经济学家的作用之一就是利用他们的理论帮助制定政策。论帮助制定政策。Harcourt, Inc. items and derived items copyright 2001 by Harcourt, Inc.Controls on Price. 价格控制价格控制uAre usually enacted when policymakers believe the market price is unfair to buyers or sellers. 当政策制定者认为市场价格对买者或卖者不公当政策制定者认为市场

4、价格对买者或卖者不公平时，往往实行价格控制。平时，往往实行价格控制。uResult in government-created price ceilings and floors. 这就促使政府实行这就促使政府实行价格上限价格上限和和价格下限价格下限政策。政策。Harcourt, Inc. items and derived items copyright 2001 by Harcourt, Inc.Controls on Price. 价格控制价格控制Price Ceiling 价格上限价格上限uA legally established maximum price at which a g

5、ood can be sold. 可以出售一种物品的法定最高价格。可以出售一种物品的法定最高价格。Price Floor 价格下限价格下限 uA legally established minimum price at which a good can be sold. 可以出售一种物品的法定最低价格。可以出售一种物品的法定最低价格。 Harcourt, Inc. items and derived items copyright 2001 by Harcourt, Inc.How Price Ceilings Affect Market OutcomesnTwo outcomes are p

6、ossible when the government imposes a price ceiling:The price ceiling is not binding if set above the equilibrium price. The price ceiling is binding if set below the equilibrium price, leading to a shortage. Harcourt, Inc. items and derived items copyright 2001 by Harcourt, Inc.价格上限如何影响市场结果价格上限如何影响

7、市场结果 当政府实行价格上限时，可能当政府实行价格上限时，可能出现两种价格：出现两种价格：uu 如果价格上限高于均衡如果价格上限高于均衡 价格，价格价格，价格上限上限没有没有限制作用。限制作用。 uu如果价格上限低于均衡如果价格上限低于均衡 价格，价格价格，价格上限对市场上限对市场有有限制作用。限制作用。A Price Ceiling That Is Not Binding.$43Quantity ofIce-CreamCones0Price ofIce-CreamConeDemandSupplyPriceceilingEquilibriumprice100Equilibriumquantit

8、y没有限制作用的价格上限没有限制作用的价格上限.$43冰激凌蛋卷的数量冰激凌蛋卷的数量0冰激凌蛋卷冰激凌蛋卷的价格的价格需求需求供给供给价格上限价格上限均衡价格均衡价格100均衡数量均衡数量A Price Ceiling That Is Binding.$3Quantity ofIce-CreamCones0Price ofIce-CreamCone2DemandSupplyEquilibriumpricePriceceilingShortage125Quantitydemanded75Quantitysupplied有限制作用的价格上限有限制作用的价格上限.$3冰激凌蛋卷的数量冰激凌蛋卷的数

9、量0冰激凌蛋卷冰激凌蛋卷的价格的价格2需求需求供给供给均衡价格均衡价格价格上限价格上限短缺短缺125需求量需求量75供給量供給量Harcourt, Inc. items and derived items copyright 2001 by Harcourt, Inc.How Price Ceilings Affect Market OutcomesnEffects of Price CeilingsnA binding price ceiling creates . shortages because QD QS.uExample: Gasoline shortage of the 1970

10、s nonprice rationinguExamples: Long lines, Discrimination by sellersHarcourt, Inc. items and derived items copyright 2001 by Harcourt, Inc.价格上限如何影响市场结果价格上限如何影响市场结果n价格上限的作用价格上限的作用n有限制作用的价格上限造成有限制作用的价格上限造成. 短缺，因为短缺，因为 QD QS.u例子例子: 70年代的汽油短缺年代的汽油短缺 非市场价格方式配给非市场价格方式配给u例子例子: 排长队排长队, 卖者歧视卖者歧视Harcourt, Inc

11、. items and derived items copyright 2001 by Harcourt, Inc.Lines at the Gas PumpIn 1973 OPEC raised the price of crude oil in world markets. Because crude oil is the major input used to make gasoline, the higher oil prices reduced the supply of gasoline.What was responsible for the long gas lines?Eco

12、nomists blame government regulations that limited the price oil companies could charge for gasoline.Harcourt, Inc. items and derived items copyright 2001 by Harcourt, Inc.加油站前的长队加油站前的长队 1973年，石油输出国组织（年，石油输出国组织（ OPEC)提高了世界石油市场的原油价格。由提高了世界石油市场的原油价格。由于原油是用于生产汽油的主要投入，于原油是用于生产汽油的主要投入，较高石油价格减少了汽油供给。较高石油价格

13、减少了汽油供给。谁对加油站前的长队负责？谁对加油站前的长队负责？经济学家把它归咎于限制石油公司对经济学家把它归咎于限制石油公司对汽油可以收取的价格的政府管制。汽油可以收取的价格的政府管制。Harcourt, Inc. items and derived items copyright 2001 by Harcourt, Inc.The Price Ceiling on Gasoline Is Not Binding. 汽油的价格上限没有限制性汽油的价格上限没有限制性$4P1Quantity of Gasoline汽油数量汽油数量0Price of Gasoline汽油价格汽油价格Q1Deman

14、d 需求需求Supply 供给供给Price ceiling价格上限价格上限1. Initially, the price ceiling is not binding.1.原来，价格上原来，价格上限没有限制性限没有限制性Harcourt, Inc. items and derived items copyright 2001 by Harcourt, Inc.The Price Ceiling on Gasoline Is Binding.P1Quantity ofGasoline0Price ofGasolineQ1DemandS1PriceceilingS22. but when sup

15、ply falls.P23. the price ceiling becomes binding.4. resulting in a shortage.Harcourt, Inc. items and derived items copyright 2001 by Harcourt, Inc.汽油的价格上限有限制性汽油的价格上限有限制性.P1汽油数量汽油数量0汽油价格汽油价格Q1需求需求S1价格上限价格上限S22. 但当供给但当供给减少时减少时.P23. 价格上限变为价格上限变为限制性的限制性的.4. 导致短缺。导致短缺。Harcourt, Inc. items and derived ite

16、ms copyright 2001 by Harcourt, Inc.Rent Control in the Short Run and Long RunuRent controls are ceilings placed on the rents that landlords may charge their tenants.uThe goal of rent control policy is to help the poor by making housing more affordable.uOne economist called rent control “the best way

17、 to destroy a city, other than bombing.”Harcourt, Inc. items and derived items copyright 2001 by Harcourt, Inc.短期中和长期中的租金控制短期中和长期中的租金控制u租金控制租金控制房东能向房客收取的房东能向房客收取的租金上限。租金上限。u这一政策的目的是帮助穷人更能租这一政策的目的是帮助穷人更能租得起住房。得起住房。u一位经济学家称租金控制是一位经济学家称租金控制是“除了除了轰炸之外毁灭一个城市的最好方法轰炸之外毁灭一个城市的最好方法”。Harcourt, Inc. items and

18、derived items copyright 2001 by Harcourt, Inc.Rent Control in the Short Run.Quantity ofApartments0Rental Price ofApartmentDemandSupplyControlled rentShortageSupply and demand for apartments are relatively inelasticHarcourt, Inc. items and derived items copyright 2001 by Harcourt, Inc.短期的租金控制短期的租金控制.

19、公寓数量公寓数量0公寓租金公寓租金价格价格需求需求供给供给受控制的租金受控制的租金短缺短缺供给与需求都相供给与需求都相对缺乏弹性对缺乏弹性Harcourt, Inc. items and derived items copyright 2001 by Harcourt, Inc.Rent Control in the Long Run.Quantity ofApartments0Rental Price ofApartmentDemandSupplyControlled rentShortageBecause the supply and demand for apartments are m

20、ore elastic.rent control causes a large shortageHarcourt, Inc. items and derived items copyright 2001 by Harcourt, Inc.长期的租金控制长期的租金控制.公寓数量公寓数量0公寓租金公寓租金价格价格需求需求供给供给受控制的租金受控制的租金短缺短缺因为供给和需求更富因为供给和需求更富有弹性有弹性租金控制导致租金控制导致大量短缺大量短缺Harcourt, Inc. items and derived items copyright 2001 by Harcourt, Inc.How Pr

21、ice Floors Affect Market OutcomesWhen the government imposes a price floor, two outcomes are possible.uThe price floor is not binding if set below the equilibrium price.uThe price floor is binding if set above the equilibrium price, leading to a surplus. Harcourt, Inc. items and derived items copyri

22、ght 2001 by Harcourt, Inc.价格下限如何影响市场结果价格下限如何影响市场结果当政府实行价格下限时，可能出当政府实行价格下限时，可能出现两种价格：现两种价格：uu 如果价格下限低于均衡价格，价格下如果价格下限低于均衡价格，价格下限没有限制作用。限没有限制作用。 uu如果价格下限高于均衡价格，价格下如果价格下限高于均衡价格，价格下限对市场有限制作用，导致过剩。限对市场有限制作用，导致过剩。Harcourt, Inc. items and derived items copyright 2001 by Harcourt, Inc.A Price Floor That Is N

23、ot Binding.$3Quantity ofIce-CreamCones0Price ofIce-CreamCone100EquilibriumquantityEquilibriumpriceDemandSupplyPricefloor2Harcourt, Inc. items and derived items copyright 2001 by Harcourt, Inc.没有限制性的价格下限没有限制性的价格下限.$3冰激凌蛋卷的数量冰激凌蛋卷的数量0冰激凌蛋卷冰激凌蛋卷的价格的价格100均衡数量均衡数量均衡价格均衡价格需求需求供给供给价格价格下限下限2A Price Floor Th

24、at Is Binding.$3Quantity ofIce-CreamCones0Price ofIce-CreamConeEquilibriumpriceDemandSupplyPrice floor$4120Quantitysupplied80QuantitydemandedSurplus有限制性的价格下限有限制性的价格下限.$3冰激凌蛋卷的数量冰激凌蛋卷的数量0冰激凌蛋卷冰激凌蛋卷的价格的价格均衡价格均衡价格需求需求供给供给价格下限价格下限$4120供給量供給量80需求量需求量过剩过剩Harcourt, Inc. items and derived items copyright 20

25、01 by Harcourt, Inc.How Price Floors Affect Market Outcomes 价格下限如何影响市场结果价格下限如何影响市场结果uA price floor prevents supply and demand from moving toward the equilibrium price and quantity.价格下限阻止供给和需求调整到均衡价格和均衡数量价格下限阻止供给和需求调整到均衡价格和均衡数量uWhen the market price hits the floor, it can fall no further, and the mar

26、ket price equals the floor price. 当市场价格达到下限时，它就不能再下降，此时市场当市场价格达到下限时，它就不能再下降，此时市场价格等于下限价格。价格等于下限价格。 Harcourt, Inc. items and derived items copyright 2001 by Harcourt, Inc.How Price Floors Affect Market OutcomesA binding price floor causes . . . a surplus because QS QD. nonprice rationing is an altern

27、ative mechanism for rationing the good, using discrimination criteria.uExamples: The minimum wage, Agricultural price supports Harcourt, Inc. items and derived items copyright 2001 by Harcourt, Inc.价格下限如何影响市场结果价格下限如何影响市场结果有限制作用的价格下限导致有限制作用的价格下限导致. . . 过剩，因为过剩，因为 QS QD. 非价格方式配给是根据歧视来配非价格方式配给是根据歧视来配给物

28、品的一种方式。给物品的一种方式。u例子例子: 最低工资最低工资, 对农产品价格的支持对农产品价格的支持 。Harcourt, Inc. items and derived items copyright 2001 by Harcourt, Inc.The Minimum Wage 最低工资最低工资An important example of a price floor is the minimum wage. Minimum wage laws dictate the lowest price possible for labor that any employer may pay. 价格下

29、限的一个重要例子是最低价格下限的一个重要例子是最低 工资。最低工资法规定了任何一工资。最低工资法规定了任何一 个雇主要支付的最低劳动工资价格个雇主要支付的最低劳动工资价格Harcourt, Inc. items and derived items copyright 2001 by Harcourt, Inc.The Minimum Wage 最低工资最低工资Quantity of Labor劳动量劳动量0Wage工资工资EquilibriumWage均衡工资均衡工资Labor demand劳动需求劳动需求Labor supply劳动供给劳动供给A Free Labor Market自由市场自

30、由市场EquilibriumEmployment均衡就业均衡就业Harcourt, Inc. items and derived items copyright 2001 by Harcourt, Inc.MinimumwageHow the Minimum Wage Affects the Labor MarketQuantity ofLabor0WageLabor demandLabor supplyQuantitysuppliedQuantitydemandedLabor surplus(unemployment)A Labor Market with a Minimum WageHar

31、court, Inc. items and derived items copyright 2001 by Harcourt, Inc.最低工资最低工资最低工资如何影响劳动市场最低工资如何影响劳动市场劳动量劳动量0工资工资劳动需求劳动需求劳动供给劳动供给供給量供給量需求量需求量劳动过剩劳动过剩(失业失业)有限制性最低工资的劳动市场有限制性最低工资的劳动市场Harcourt, Inc. items and derived items copyright 2001 by Harcourt, Inc.Taxes 税收税收Governments levy taxes to raise revenue

32、for public projects. 政府利用税收为公共项目筹资政府利用税收为公共项目筹资Harcourt, Inc. items and derived items copyright 2001 by Harcourt, Inc.How Taxes on Buyers (and Sellers) Affect Market OutcomesnTaxes discourage market activity.nWhen a good is taxed, the quantity sold is smaller. nBuyers and sellers share the tax burde

33、n.Harcourt, Inc. items and derived items copyright 2001 by Harcourt, Inc.对买者和卖者收税如何影响市场结果对买者和卖者收税如何影响市场结果u税收抑制了市场活动。税收抑制了市场活动。u当一种物品被征税时，当一种物品被征税时，它的销售量减少。它的销售量减少。 u买者和卖者分摊税收负买者和卖者分摊税收负担。担。Harcourt, Inc. items and derived items copyright 2001 by Harcourt, Inc.Elasticity and Tax IncidenceuTax inciden

34、ce is the study of who bears the burden of a tax. uTaxes result in a change in market equilibrium.uBuyers pay more and sellers receive less, regardless of whom the tax is levied on. Harcourt, Inc. items and derived items copyright 2001 by Harcourt, Inc.弹性与税收归宿弹性与税收归宿u税收归宿税收归宿 关于由谁承担税收关于由谁承担税收负担的研究。负

35、担的研究。 u税收导致市场均衡的变动。税收导致市场均衡的变动。u不管向谁收税，买者支付的价格不管向谁收税，买者支付的价格更高，卖者收到的价格更低。更高，卖者收到的价格更低。Impact of a 50 Tax Levied on Buyers.3.00Quantity ofIce-Cream Cones0Price ofIce-CreamCone100D1Supply, S1A tax on buyersshifts the demandcurve downwardby the size ofthe tax ($0.50).D2向买者征收向买者征收0.5美元税收的影响美元税收的影响3.00冰激

36、凌蛋卷的数量冰激凌蛋卷的数量0冰激凌蛋卷冰激凌蛋卷的价格的价格100D1供给供给, S1对买者征税使需求对买者征税使需求曲线下移，其幅度曲线下移，其幅度为税收量（为税收量（0.5美元）美元）D23.00Quantity ofIce-Cream Cones0Price ofIce-CreamCone10090$3.30PricebuyerspayD1D2Equilibriumwith taxSupply, S1Equilibrium without taxImpact of a 50 Tax Levied on Buyers.2.80PricesellersreceivePricewithout

37、tax Tax ($0.50)3.00冰激凌蛋卷的数量冰激凌蛋卷的数量0冰激凌蛋卷冰激凌蛋卷的价格的价格10090$3.30买者支付买者支付的价格的价格D1D2有税收时有税收时的均衡的均衡供给供给, S1没有税收时的均衡没有税收时的均衡向买者征收向买者征收0.5美元税收的影响美元税收的影响2.80卖者得到卖者得到的价格的价格没有税收没有税收时的价格时的价格 税收税收 0.5美元美元Harcourt, Inc. items and derived items copyright 2001 by Harcourt, Inc.What was the impact of tax?uTaxes dis

38、courage market activity.uWhen a good is taxed, the quantity sold is smaller. uBuyers and sellers share the tax burden.Harcourt, Inc. items and derived items copyright 2001 by Harcourt, Inc.税收的潜在影响是什么税收的潜在影响是什么?u税收抑制了市场活动。税收抑制了市场活动。u当一种物品被征税时，当一种物品被征税时，它的销售量减少。它的销售量减少。 u买者和卖者分摊税收负买者和卖者分摊税收负担。担。3.00Qu

39、antity ofIce-Cream Cones0Price ofIce-CreamCone10090S1S2Demand, D1Impact of a 50 Tax on Sellers.Price without tax2.80Price sellers receive$3.30Price buyers payEquilibrium without taxA tax on sellers shifts the supply curve upward by the amount of the tax ($0.50). Tax ($0.50)Equilibriumwith tax3.00冰激凌

40、蛋卷的数量冰激凌蛋卷的数量0冰激凌蛋卷冰激凌蛋卷的价格的价格10090S1S2需求需求, D1向卖者征收向卖者征收0.5美元税收的影响美元税收的影响没有税收没有税收时的价格时的价格2.80卖者得卖者得到的价到的价格格$3.30买者支付买者支付的价格的价格没有税收时的均衡没有税收时的均衡向卖者征税使供给向卖者征税使供给曲线向上移动，移曲线向上移动，移动量为税收（动量为税收（0.5美元）美元） 税收税收 0.5美元美元有税收时有税收时的均衡的均衡Harcourt, Inc. items and derived items copyright 2001 by Harcourt, Inc.A Payr

41、oll TaxQuantity ofLabor0WageWage without taxLabor demandLabor supplyTax wedgeWage firms payWage workers receiveHarcourt, Inc. items and derived items copyright 2001 by Harcourt, Inc.工薪税工薪税劳动量劳动量0工资工资没有税收没有税收时的工资时的工资劳动需求劳动需求劳动供给劳动供给税收楔子税收楔子企业支付企业支付的工资的工资个人得到个人得到的工资的工资Harcourt, Inc. items and derived

42、items copyright 2001 by Harcourt, Inc.Elasticity and Tax IncidenceuIn what proportions is the burden of the tax divided?uHow do the effects of taxes on sellers compare to those levied on buyers?The answers to these questions depend on the elasticity of demand and the elasticity of supply.Harcourt, I

43、nc. items and derived items copyright 2001 by Harcourt, Inc.弹性与税收归宿弹性与税收归宿u税收负担是按什么比例分摊的？税收负担是按什么比例分摊的？u怎样比较向买者征税与向卖者征怎样比较向买者征税与向卖者征税的结果？税的结果？这些问题的答案取决于这些问题的答案取决于需求弹性需求弹性 和和供给弹性供给弹性 。Harcourt, Inc. items and derived items copyright 2001 by Harcourt, Inc.（a）Elastic Supply, Inelastic Demand.Quantity0P

44、riceDemandSupplyTax1. When supply is moreelastic than demand.2. .theincidence of thetax falls moreheavily onconsumers.3. .than onproducers.Price without taxPrice buyers payPrice sellers receiveFigure 9 How the Burden of a Tax Is DividedHarcourt, Inc. items and derived items copyright 2001 by Harcour

45、t, Inc.（a）供给富有弹性，需求缺乏弹性）供给富有弹性，需求缺乏弹性.数量数量0价格价格需求需求供给供给税收税收1.当供给比需求富当供给比需求富有弹性时有弹性时.2. 税收归宿税收归宿更多地由消费更多地由消费者承担者承担.3. 更少地由更少地由生产者承担。生产者承担。没有税收的价格没有税收的价格买者支付的价格买者支付的价格 卖者得到的价格卖者得到的价格图图9. 税收负担如何分摊的税收负担如何分摊的Harcourt, Inc. items and derived items copyright 2001 by Harcourt, Inc.(b)Inelastic Supply, Elast

46、ic Demand.Quantity0PriceDemandSupplyPrice without taxTax1. When demand is moreelastic than supply.2. .theincidence of the tax falls more heavily on producers.3. .than on consumers.Price buyers payPrice sellers receiveFigure 9 How the Burden of a Tax Is DividedHarcourt, Inc. items and derived items c

47、opyright 2001 by Harcourt, Inc.(b)供给缺乏弹性，需求富有弹性供给缺乏弹性，需求富有弹性.数量数量0价格价格需求需求供给供给 没有税收的价格没有税收的价格税收税收1. 当需求比供给富有弹性时当需求比供给富有弹性时.2. 税收归宿更多税收归宿更多地由生产者承担地由生产者承担.3. 更少地由消费者承担更少地由消费者承担 买者支付的价格买者支付的价格 卖者得到的价格卖者得到的价格图图9. 税收负担如何分摊的税收负担如何分摊的Harcourt, Inc. items and derived items copyright 2001 by Harcourt, Inc.So

48、, how is the burden of the tax divided?The burden of a tax falls more heavily on the side of the market that is less elastic.ELASTICITY AND TAX INCIDENCE Harcourt, Inc. items and derived items copyright 2001 by Harcourt, Inc.所以所以, 税收负担是如何分摊的税收负担是如何分摊的?税收负担更多地落税收负担更多地落在缺乏弹性的市场在缺乏弹性的市场一方身上。一方身上。弹性与税收归

49、宿弹性与税收归宿 Harcourt, Inc. items and derived items copyright 2001 by Harcourt, Inc.SummaryuPrice controls include price ceilings and price floors.u A price ceiling is a legal maximum on the price of a good or service. An example is rent control.uA price floor is a legal minimum on the price of a good o

50、r a service. An example is the minimum wage.Harcourt, Inc. items and derived items copyright 2001 by Harcourt, Inc.小结小结u价格控制包括价格上限和价格下限。价格控制包括价格上限和价格下限。u 价格上限是某种物品或劳务价格法价格上限是某种物品或劳务价格法定的最高限。租金控制是一个例子。定的最高限。租金控制是一个例子。u价格下限是某种物品或劳务价格法定价格下限是某种物品或劳务价格法定的最低限。最低工资是一个例子。的最低限。最低工资是一个例子。Harcourt, Inc. items