曼昆經濟學原理微觀部分課件

1、Supply, Demand, and Government PoliciesIn a free, unregulated market system, market forces establish equilibrium prices and exchange quantities.While equilibrium conditions may be efficient, it may be true that not everyone is satisfied. One of the roles of economists is to use their theories to ass

2、ist in the development of policies.供給、需求與政府政策在一個自由、無管制的市場系統(tǒng)中，市場力量實現(xiàn)均衡價格和均衡交易量。這種均衡結果也許是有效的，但并不是每個人對此都感到滿意。 經濟學家的作用之一就是利用他們的理論幫助制定政策。Controls on Price. 價格控制Are usually enacted when policymakers believe the market price is unfair to buyers or sellers. 當政策制定者認為市場價格對買者或賣者不公平時，往往實行價格控制。Result in governme

3、nt-created price ceilings and floors. 這就促使政府實行價格上限和價格下限政策。Controls on Price. 價格控制Price Ceiling 價格上限A legally established maximum price at which a good can be sold. 可以出售一種物品的法定最高價格。Price Floor 價格下限 A legally established minimum price at which a good can be sold. 可以出售一種物品的法定最低價格。 How Price Ceilings Af

4、fect Market OutcomesTwo outcomes are possible 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. 價格上限如何影響市場結果 當政府實行價格上限時，可能出現(xiàn)兩種價格： 如果價格上限高于均衡 價格，價格上限沒

5、有限制作用。 如果價格上限低于均衡 價格，價格上限對市場有限制作用。A Price Ceiling That Is Not Binding.$43Quantity ofIce-CreamCones0Price ofIce-CreamConeDemandSupplyPriceceilingEquilibriumprice100Equilibriumquantity沒有限制作用的價格上限.$43冰激凌蛋卷的數量0冰激凌蛋卷的價格需求供給價格上限均衡價格100均衡數量A Price Ceiling That Is Binding.$3Quantity ofIce-CreamCones0Price o

6、fIce-CreamCone2DemandSupplyEquilibriumpricePriceceilingShortage125Quantitydemanded75Quantitysupplied有限制作用的價格上限.$3冰激凌蛋卷的數量0冰激凌蛋卷的價格2需求供給均衡價格價格上限短缺125需求量75供給量How Price Ceilings Affect Market OutcomesEffects of Price CeilingsA binding price ceiling creates . shortages because QD QS.Example: Gasoline sh

7、ortage of the 1970s nonprice rationingExamples: Long lines, Discrimination by sellers價格上限如何影響市場結果價格上限的作用有限制作用的價格上限造成. 短缺，因為 QD QS.例子: 70年代的汽油短缺 非市場價格方式配給例子: 排長隊, 賣者歧視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 ga

8、soline, the higher oil prices reduced the supply of gasoline.What was responsible for the long gas lines?Economists blame government regulations that limited the price oil companies could charge for gasoline.加油站前的長隊 1973年，石油輸出國組織（ OPEC)提高了世界石油市場的原油價格。由于原油是用于生產汽油的主要投入，較高石油價格減少了汽油供給。誰對加油站前的長隊負責？經濟學家把它

9、歸咎于限制石油公司對汽油可以收取的價格的政府管制。The Price Ceiling on Gasoline Is Not Binding. 汽油的價格上限沒有限制性$4P1Quantity of Gasoline汽油數量0Price of Gasoline汽油價格Q1Demand 需求Supply 供給Price ceiling價格上限1. Initially, the price ceiling is not binding.1.原來，價格上限沒有限制性The Price Ceiling on Gasoline Is Binding.P1Quantity ofGasoline0Price

10、ofGasolineQ1DemandS1PriceceilingS22. but when supply falls.P23. the price ceiling becomes binding.4. resulting in a shortage.汽油的價格上限有限制性.P1汽油數量0汽油價格Q1需求S1價格上限S22. 但當供給減少時.P23. 價格上限變?yōu)橄拗菩缘?4. 導致短缺。Rent Control in the Short Run and Long RunRent controls are ceilings placed on the rents that landlords m

11、ay charge their tenants.The goal of rent control policy is to help the poor by making housing more affordable.One economist called rent control “the best way to destroy a city, other than bombing.”短期中和長期中的租金控制租金控制房東能向房客收取的租金上限。這一政策的目的是幫助窮人更能租得起住房。一位經濟學家稱租金控制是“除了轟炸之外毀滅一個城市的最好方法”。Rent Control in the S

12、hort Run.Quantity ofApartments0Rental Price ofApartmentDemandSupplyControlled rentShortageSupply and demand for apartments are relatively inelastic短期的租金控制.公寓數量0公寓租金價格需求供給受控制的租金短缺供給與需求都相對缺乏彈性Rent Control in the Long Run.Quantity ofApartments0Rental Price ofApartmentDemandSupplyControlled rentShortage

13、Because the supply and demand for apartments are more elastic.rent control causes a large shortage長期的租金控制.公寓數量0公寓租金價格需求供給受控制的租金短缺因為供給和需求更富有彈性租金控制導致大量短缺How Price Floors Affect Market OutcomesWhen the government imposes a price floor, two outcomes are possible.The price floor is not binding if set bel

14、ow the equilibrium price.The price floor is binding if set above the equilibrium price, leading to a surplus. 價格下限如何影響市場結果當政府實行價格下限時，可能出現(xiàn)兩種價格： 如果價格下限低于均衡價格，價格下限沒有限制作用。 如果價格下限高于均衡價格，價格下限對市場有限制作用，導致過剩。A Price Floor That Is Not Binding.$3Quantity ofIce-CreamCones0Price ofIce-CreamCone100Equilibriumquan

15、tityEquilibriumpriceDemandSupplyPricefloor2沒有限制性的價格下限.$3冰激凌蛋卷的數量0冰激凌蛋卷的價格100均衡數量均衡價格需求供給價格下限2A Price Floor That Is Binding.$3Quantity ofIce-CreamCones0Price ofIce-CreamConeEquilibriumpriceDemandSupplyPrice floor$4120Quantitysupplied80QuantitydemandedSurplus有限制性的價格下限.$3冰激凌蛋卷的數量0冰激凌蛋卷的價格均衡價格需求供給價格下限$4

16、120供給量80需求量過剩How Price Floors Affect Market Outcomes 價格下限如何影響市場結果A price floor prevents supply and demand from moving toward the equilibrium price and quantity.價格下限阻止供給和需求調整到均衡價格和均衡數量When the market price hits the floor, it can fall no further, and the market price equals the floor price. 當市場價格達到下限時

17、，它就不能再下降，此時市場價格等于下限價格。 How Price Floors Affect Market OutcomesA binding price floor causes . . . a surplus because QS QD. nonprice rationing is an alternative mechanism for rationing the good, using discrimination criteria.Examples: The minimum wage, Agricultural price supports 價格下限如何影響市場結果有限制作用的價格下

18、限導致. . . 過剩，因為 QS QD. 非價格方式配給是根據歧視來配給物品的一種方式。例子: 最低工資, 對農產品價格的支持 。The Minimum Wage 最低工資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. 價格下限的一個重要例子是最低 工資。最低工資法規(guī)定了任何一 個雇主要支付的最低勞動工資價格The Minimum Wage 最低工

19、資Quantity of Labor勞動量0Wage工資EquilibriumWage均衡工資Labor demand勞動需求Labor supply勞動供給A Free Labor Market自由市場EquilibriumEmployment均衡就業(yè)MinimumwageHow the Minimum Wage Affects the Labor MarketQuantity ofLabor0WageLabor demandLabor supplyQuantitysuppliedQuantitydemandedLabor surplus(unemployment)A Labor Marke

20、t with a Minimum Wage最低工資最低工資如何影響勞動市場勞動量0工資勞動需求勞動供給供給量需求量勞動過剩(失業(yè))有限制性最低工資的勞動市場Taxes 稅收Governments levy taxes to raise revenue for public projects. 政府利用稅收為公共項目籌資How Taxes on Buyers (and Sellers) Affect Market OutcomesTaxes discourage market activity.When a good is taxed, the quantity sold is smaller.

21、 Buyers and sellers share the tax burden.對買者和賣者收稅如何影響市場結果稅收抑制了市場活動。當一種物品被征稅時，它的銷售量減少。 買者和賣者分攤稅收負擔。Elasticity and Tax IncidenceTax incidence is the study of who bears the burden of a tax. Taxes result in a change in market equilibrium.Buyers pay more and sellers receive less, regardless of whom the t

22、ax is levied on. 彈性與稅收歸宿稅收歸宿 關于由誰承擔稅收負擔的研究。 稅收導致市場均衡的變動。不管向誰收稅，買者支付的價格更高，賣者收到的價格更低。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向買者征收0.5美元稅收的影響3.00冰激凌蛋卷的數量0冰激凌蛋卷的價格

23、100D1供給, S1對買者征稅使需求曲線下移，其幅度為稅收量（0.5美元）D23.00Quantity ofIce-Cream Cones0Price ofIce-CreamCone10090$3.30PricebuyerspayD1D2Equilibriumwith taxSupply, S1Equilibrium without taxImpact of a 50 Tax Levied on Buyers.2.80PricesellersreceivePricewithouttax Tax ($0.50)3.00冰激凌蛋卷的數量0冰激凌蛋卷的價格10090$3.30買者支付的價格D1D2

24、有稅收時的均衡供給, S1沒有稅收時的均衡向買者征收0.5美元稅收的影響2.80賣者得到的價格沒有稅收時的價格 稅收 0.5美元What was the impact of tax?Taxes discourage market activity.When a good is taxed, the quantity sold is smaller. Buyers and sellers share the tax burden.稅收的潛在影響是什么?稅收抑制了市場活動。當一種物品被征稅時，它的銷售量減少。 買者和賣者分攤稅收負擔。3.00Quantity ofIce-Cream Cones0P

25、rice 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冰激凌蛋卷的數量0冰激凌蛋卷的價格10090S1S2需求,

26、 D1向賣者征收0.5美元稅收的影響沒有稅收時的價格2.80賣者得到的價格$3.30買者支付的價格沒有稅收時的均衡向賣者征稅使供給曲線向上移動，移動量為稅收（0.5美元） 稅收 0.5美元有稅收時的均衡A Payroll TaxQuantity ofLabor0WageWage without taxLabor demandLabor supplyTax wedgeWage firms payWage workers receive工薪稅勞動量0工資沒有稅收時的工資勞動需求勞動供給稅收楔子企業(yè)支付的工資個人得到的工資Elasticity and Tax IncidenceIn what pro

27、portions is the burden of the tax divided?How 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.彈性與稅收歸宿稅收負擔是按什么比例分攤的？怎樣比較向買者征稅與向賣者征稅的結果？這些問題的答案取決于需求彈性 和供給彈性 。（a）Elastic Supply, Inelastic

28、 Demand.Quantity0PriceDemandSupplyTax1. 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 Divided（a）供給富有彈性，需求缺乏彈性.數量0價格需求供給稅收當供給比需求富有彈性時.2. 稅收歸

29、宿更多地由消費者承擔.3. 更少地由生產者承擔。沒有稅收的價格買者支付的價格 賣者得到的價格圖9. 稅收負擔如何分攤的(b)Inelastic Supply, Elastic 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 recei

30、veFigure 9 How the Burden of a Tax Is Divided(b)供給缺乏彈性，需求富有彈性.數量0價格需求供給 沒有稅收的價格稅收1. 當需求比供給富有彈性時.2. 稅收歸宿更多地由生產者承擔.3. 更少地由消費者承擔 買者支付的價格 賣者得到的價格圖9. 稅收負擔如何分攤的So, 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 所以, 稅收負擔是如何分攤的?稅收負擔更多地落在缺乏彈性的市場一方身上。彈性與稅收歸宿 SummaryPrice controls include price cei