1、Supply, Demand and Government PoliciesChapter 6供給、需求與政府政策供給、需求與政府政策Supply, Demand, and GovernmentPolicies在自由的、無管制的市場(chǎng)中，市場(chǎng)的力量建立均衡價(jià)格，決定交換的數(shù)量In a free, unregulated market system, market forces establish equilibrium prices and exchange quantities.雖然均衡的狀態(tài)是有效率的，但也許并非使每人都滿意。While equilibrium conditions may

2、be efficient, it may be true that not everyone is satisfied.經(jīng)濟(jì)學(xué)家的作用之一是運(yùn)用他們的理論幫助制定政府政策。One of the roles of economists is to use their theories to assist in the development of policies.價(jià)格控制Price Controls.實(shí)行價(jià)格控制通常是政府相信市場(chǎng)價(jià)格對(duì)買方或賣方不公平。Are usually enacted when policymakers believe the market price is unfai

3、r to buyers or sellers.兩種價(jià)格控制：價(jià)格上限和價(jià)格下限Result in government-created price ceilings and floors.常常引發(fā)事與愿違的結(jié)果（效率和公平損失）經(jīng)濟(jì)分析的重要性：供給和需求工具價(jià)格上限與價(jià)格下限Price Ceilings & Price Floors價(jià)格上限（Price Ceiling ）法定最高價(jià)格A legally established maximum price at which agood can be sold.價(jià)格下限（Price Floor）法定最低價(jià)格A legally establishe

4、d minimum price at which agood can be sold.價(jià)格上限Price Ceilings 政府實(shí)行價(jià)格上限時(shí)有兩種可能結(jié)果 Two outcomes are possible when the government imposes a price ceiling:當(dāng)價(jià)格上限高于均衡價(jià)格時(shí)，價(jià)格上限沒有限制性The price ceiling is not binding if set above the equilibrium price.當(dāng)價(jià)格上限低于均衡價(jià)格時(shí)，價(jià)格上限有限制性 The price ceiling is binding if set bel

5、ow the equilibrium price, leading to a shortage.沒有限制作用的價(jià)格上限A Price Ceiling That Is Not Binding.$43Quantity ofIce-CreamCones0Price ofIce-CreamConeDemandSupplyPriceceilingEquilibriumprice100EquilibriumquantityHarcourt, Inc. items and derived items copyright 2001 by Harcourt, Inc.有限制作用的價(jià)格上限A Price Ceil

6、ing That Is Binding.$3Quantity ofIce-CreamCones0Price ofIce-CreamCone2DemandSupplyEquilibriumpricePriceceilingShortage125Quantitydemanded75QuantitysuppliedHarcourt, Inc. items and derived items copyright 2001 by Harcourt, Inc.實(shí)行價(jià)格上限的結(jié)果(1)Effects of Price Ceilings有限制作用的價(jià)格上限導(dǎo)致短缺A binding price ceiling

7、 creates shortages因?yàn)樾枨罅看笥诠┙o量because QD QS.舉例： 70年代：食品 80年代：原材料（如鋼鐵） 90年代：發(fā)售原始股實(shí)行價(jià)格上限的結(jié)果(2)Effects of Price Ceilings有限制作用的價(jià)格上限導(dǎo)致配給A binding price ceiling creates rationing因?yàn)橛卸倘盉ecause of shortage舉例： 排隊(duì)queuing 賣者對(duì)買者的歧視discrimination 發(fā)票憑證coupons “走后門going through a “back door”誰應(yīng)該對(duì)排長(zhǎng)隊(duì)負(fù)責(zé)？誰應(yīng)該對(duì)走后門負(fù)責(zé)？ 經(jīng)濟(jì)學(xué)認(rèn)為

8、是政府的價(jià)格控制政策Economists blame government pricecontrols that limited the price the sellercould charge.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 wa

9、s responsible for the long gas lines?Economists blame government regulations that limited the price oil companies could charge for gasoline.價(jià)格上限沒有限制性The Price Ceiling on Gasoline Is Not Binding$4P1Quantity ofGasoline0Price ofGasolineQ1DemandSupplyPriceceiling1. Initially, the price ceiling is not bi

10、nding.價(jià)格上限變?yōu)橛邢拗菩訲he Price Ceiling on Gasoline Is BindingP1Quantity ofGasoline0Price ofGasolineQ1DemandS1PriceceilingS22. but when supply falls.P23. the price ceiling becomes binding.4. resulting in a shortage.房租控制Rent Control房租控制是指房主出租房屋時(shí)所收房租的上限。Rent controls are ceilings placed on the rentsthat lan

11、dlords may charge their tenants.房租控制的目的幫助窮人，使他們能負(fù)得起房租。The goal of rent control policy is to help thepoor by making housing more affordable.一名經(jīng)濟(jì)學(xué)家稱房租控制是“除了炸彈外摧毀一座城市的最好的方法”O(jiān)ne economist called rent control “the best way to destroy a city, other than bombing.”房租控制在短期內(nèi)的結(jié)果Rent Control in the Short Run.Qu

12、antity ofApartments0Rental Price ofApartmentDemandSupplyControlled rentShortageSupply and demand for apartments are relatively inelastic房租控制在長(zhǎng)期內(nèi)的結(jié)果Rent Control in the Long Run.Quantity ofApartments0Rental Price ofApartmentDemandSupplyControlled rentShortageBecause the supply and demand for apartment

13、s are more elastic.rent control causes a large shortage價(jià)格下限Price Floors政府實(shí)行價(jià)格下限時(shí)有兩種可能結(jié)果When the government imposes a price floor, two outcomes are possible.當(dāng)價(jià)格下限低于均衡價(jià)格時(shí)，價(jià)格下限沒有限制性。The price floor is not binding if set below the equilibrium price.當(dāng)價(jià)格下限高于均衡價(jià)格時(shí)，價(jià)格下限有限制性導(dǎo)致過剩。The price floor is binding if

14、 set above the equilibriumprice, leading to a surplus.沒有限制作用的價(jià)格下限A Price Floor That Is Not Binding.$3Quantity ofIce-CreamCones0Price ofIce-CreamCone100EquilibriumquantityEquilibriumpriceDemandSupplyPricefloor2有限制作用的價(jià)格下限A Price Floor That Is Binding.$3Quantity ofIce-CreamCones0Price ofIce-CreamConeEq

15、uilibriumpriceDemandSupplyPrice floor$4120Quantitysupplied80QuantitydemandedSurplusHarcourt, Inc. items and derived items copyright 2001 by Harcourt, Inc.實(shí)行價(jià)格下限的結(jié)果Effects of a Price Floor價(jià)格下限阻止供給和需求向均衡價(jià)格和數(shù)量移動(dòng)A price floor prevents supply and demand from moving toward the equilibrium price and quanti

16、ty.市場(chǎng)價(jià)格最多降到價(jià)格下限When the market price hits the floor, it can fall no further, and the market price equals the floor price.實(shí)行價(jià)格下限的結(jié)果Effects of a Price Floor有限制作用的價(jià)格下限導(dǎo)致過剩因?yàn)楣┙o量大于需求量。A binding price floor causes a surplus because QSQD.非價(jià)格的配給機(jī)制：使用歧視性標(biāo)準(zhǔn)配給物品nonprice rationing is an alternative mechanism fo

17、rrationing the good, using discrimination criteria.例子：最低工資、農(nóng)產(chǎn)品保護(hù)價(jià)格Examples: The minimum wage Agricultural price supports最低工資The Minimum Wage價(jià)格下限的一個(gè)重要例子是最低工資An important example of a price floor is the minimum wage.最低工資法規(guī)定任何雇主必須支付受雇者的最低價(jià)格Minimum wage laws dictate the lowest price possible for labor t

18、hat any employer may pay.最低工資The Minimum WageQuantity ofLabor0WageEquilibriumwageLabor demandLabor supplyA Free Labor MarketEquilibriumemploymentMinimumwage最低工資The Minimum WageQuantity ofLabor0WageLabor demandLabor supplyQuantitysuppliedQuantitydemandedLabor surplus(unemployment)A Labor Market with

19、a Minimum Wage稅收Taxes政府用征稅方式來為公共項(xiàng)目籌款Governments levy taxes to raise revenue for public projects.稅收Taxes稅收歸宿(負(fù)擔(dān))研究誰承受稅收負(fù)擔(dān)Tax incidence is the study of who bears the burden of a tax. 稅收改變市場(chǎng)均衡Taxes result in a change in market equilibrium.不管向誰征稅，稅收總使得買者付出更多而賣者得到更少Buyers pay more and sellers receive les

20、s, regardless of whom the tax is levied on.向買者征稅的結(jié)果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).D2Copyright 2001 by Harcourt, Inc. All rights reserved3.00Quantity ofI

21、ce-Cream Cones0Price ofIce-CreamCone10090$3.30PricebuyerspayD1D2Equilibriumwith taxSupply, S1Equilibrium without tax向買者征稅的結(jié)果Impact of a 50 Tax Levied on Buyers.2.80PricesellersreceiveCopyright 2001 by Harcourt, Inc. All rights reservedPricewithouttax Tax ($0.50)稅收的影響是什么？What was the impact of tax?稅收

22、抑制市場(chǎng)活動(dòng)Taxes discourage marketactivity.一個(gè)商品被征稅，銷售量減小When a good is taxed, thequantity sold is smaller.買賣雙方都承擔(dān)稅收負(fù)擔(dān)Buyers and sellers sharethe tax burden.3.00Quantity ofIce-Cream Cones0Price ofIce-CreamCone10090S1S2Demand, D1向賣者征稅的結(jié)果Impact of a 50 Tax on Sellers.Price without tax2.80Price sellers recei

23、ve$3.30Price buyers payEquilibrium without taxCopyright 2001 by Harcourt, Inc. All rights reservedA tax on sellers shifts the supply curve upward by the amount of the tax ($0.50). Tax ($0.50)Equilibriumwith tax比較向買者征稅和向賣者征稅的結(jié)果Compare the effects of taxes onsellers with those on buyers?對(duì)買者征稅和對(duì)賣者征稅結(jié)果是

24、相同的！ 買者和賣者分?jǐn)偠愂肇?fù)擔(dān) 對(duì)買者征稅和對(duì)賣者征稅的唯一差別是誰把錢交給政府。A Payroll TaxQuantity ofLabor0WageWage without taxLabor demandLabor supplyTax wedgeWage firms payWage workers receive稅收負(fù)擔(dān)The Incidence of Tax稅收負(fù)擔(dān)在買者和賣者間是按何種比例劃分的？In what proportions is the burden of the tax divided?答案取決于需求彈性和供給彈性The answers to these question

25、s depend on the elasticity of demand and the elasticity of supply.富有彈性的供給、缺乏彈性的需求Elastic Supply, Inelastic Demand.Quantity0PriceDemandSupplyTax1. When supply is moreelastic than demand.2. .theincidence of thetax falls moreheavily onconsumers.3. .than onproducers.Price without taxPrice buyers payPric

26、e sellers receive缺乏彈性的供給、富有彈性的需求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 receive稅收負(fù)擔(dān)是如何劃分的？So, how is the bu

27、rden of thetax divided?稅收負(fù)擔(dān)更多地落在缺乏彈性的市場(chǎng)一方The burden of a taxfalls more heavily onthe side of themarket that is lesselastic. 為什么？ Why?彈性是衡量當(dāng)條件變得不利時(shí)，買者或賣者離開市場(chǎng)的意愿。當(dāng)征稅時(shí)，不能輕而易舉離開市場(chǎng)的一方承擔(dān)更多的稅收負(fù)擔(dān)。舉例：工薪稅與社會(huì)保障Payroll Tax and Social Security 工薪稅在雇員和企業(yè)之間的稅收負(fù)擔(dān)的劃分與法律規(guī)定的劃分（比如平攤）無關(guān)。 因?yàn)閯趧?dòng)的供給遠(yuǎn)比勞動(dòng)的需求缺乏彈性。 所以雇員而不是企業(yè)承擔(dān)了大部分工薪稅的負(fù)擔(dān)。舉例：誰支付奢侈品稅？Who Pays Taxes on Luxury Goods?對(duì)奢侈品征稅似乎是向富人征稅的有效方式。 但是，因?yàn)閷?duì)某一奢侈品的需求極富彈性，但供應(yīng)在短期內(nèi)缺乏彈性 所以，稅收負(fù)擔(dān)主要落在生產(chǎn)者（企業(yè)和工人）身上。 事與愿違：奢侈品稅的負(fù)擔(dān)落在中產(chǎn)階級(jí)身上比富人身上要多。 總結(jié) Summary價(jià)