微經(jīng)3李雪松老師版9the analysis of competitive markets

Chapter9競爭性市場的分析TheAnalysisofCompetitiveMarketsChapter9Slide2TopicstobeDiscussed政府政策損益評(píng)估—消費(fèi)者剩余和生產(chǎn)者剩余EvaluatingtheGainsandLossesfromGovernmentPolicies--ConsumerandProducerSurplus競爭性市場的效率TheEfficiencyofaCompetitiveMarket最低價(jià)格MinimumPricesChapter9Slide3TopicstobeDiscussed價(jià)格支持和生產(chǎn)配額PriceSupportsandProductionQuotasChapter9Slide4政府政策損益評(píng)估—消費(fèi)者剩余和生產(chǎn)者剩余EvaluatingtheGainsandLossesfromGovernmentPolicies--ConsumerandProducerSurplus復(fù)習(xí)Review消費(fèi)者剩余是消費(fèi)者收到的超過其為物品所支付費(fèi)用的總利益或價(jià)值.Consumersurplusisthetotalbenefitorvaluethatconsumersreceivebeyondwhattheypayforthegood.Chapter9Slide5政府政策損益評(píng)估—消費(fèi)者剩余和生產(chǎn)者剩余

EvaluatingtheGainsandLossesfromGovernmentPolicies--ConsumerandProducerSurplus復(fù)習(xí)Review生產(chǎn)者剩余是生產(chǎn)者收到的超過生產(chǎn)某種物品所費(fèi)成本的總利益或收入.

Producersurplusisthetotalbenefitorrevenuethatproducersreceivebeyondwhatitcosttoproduceagood.生產(chǎn)者剩余ProducerSurplus在0和Q0

之間生產(chǎn)者得到來自銷售每個(gè)產(chǎn)品的凈利益--生產(chǎn)者剩余.消費(fèi)者剩余ConsumerSurplus消費(fèi)者和生產(chǎn)者剩余

ConsumerandProducerSurplusQuantity0PriceSD5Q0消費(fèi)者C107消費(fèi)者B消費(fèi)者A在0和Q0

之間,消費(fèi)者A和B從購買產(chǎn)品中得到凈利益--消費(fèi)者剩余Chapter9Slide7為確定政府政策福利效應(yīng),我們衡量消費(fèi)者和生產(chǎn)者剩余的得與失.Todeterminethewelfareeffectofagovernmentalpolicywecanmeasurethegainorlossinconsumerandproducersurplus.政府政策損益評(píng)估—消費(fèi)者剩余和生產(chǎn)者剩余EvaluatingtheGainsandLossesfromGovernmentPolicies--ConsumerandProducerSurplusChapter9Slide8政府政策損益評(píng)估—消費(fèi)者剩余和生產(chǎn)者剩余

EvaluatingtheGainsandLossesfromGovernmentPolicies--ConsumerandProducerSurplus福利效應(yīng)WelfareEffects政策干預(yù)市場引起的得與失Gainsandlossescausedbygovernmentinterventioninthemarket.Chapter9Slide9生產(chǎn)者的失是A長方形和C三角形的總和.B

和C

三角形一起衡量無謂損失.BAC消費(fèi)者的得是在A長方形和B三角形之間的差額.無謂損失由于價(jià)格控制,消費(fèi)者和生產(chǎn)者剩余的變化ChangeinConsumerandProducerSurplusfromPriceControlsQuantityPriceSDP0Q0PmaxQ1Q2設(shè)政府實(shí)施價(jià)格上限Pmax處于市場出清價(jià)格P0之下.Chapter9Slide10觀察:Observations:總損失等于B+C的面積.剩余的總變化=(A-B)+(-A-C)=-B–C.無謂損失是價(jià)格控制的無效率或生產(chǎn)者剩余的所失超過消費(fèi)者剩余的所得.Thedeadweightlossistheinefficiencyofthepricecontrolsorthelossoftheproducersurplusexceedsthegainfromconsumersurplus.由于價(jià)格控制,消費(fèi)者和生產(chǎn)者剩余的變化ChangeinConsumerandProducerSurplusfromPriceControlsChapter9Slide11觀察Observation當(dāng)需求非常缺乏彈性時(shí),消費(fèi)者經(jīng)歷消費(fèi)者剩余的凈損失Consumerscanexperienceanetlossinconsumersurpluswhenthedemandissufficientlyinelastic由于價(jià)格控制,消費(fèi)者和生產(chǎn)者剩余的變化ChangeinConsumerandProducerSurplusfromPriceControlsChapter9Slide12BAPmaxCQ1若需求非常缺乏彈性,

B

三角能夠大于A長方形,消費(fèi)者遭受來自價(jià)格控制的凈損失.1979的例子石油價(jià)格控制和汽油短缺SD需求缺乏彈性時(shí)的價(jià)格控制

EffectofPriceControlsWhenDemandIsInelasticQuantityPriceP0Q2Chapter9Slide13價(jià)格控制和天然氣短缺PriceControlsand

NaturalGasShortages1975年價(jià)格控制創(chuàng)造出天然氣的短缺.1975Pricecontrolscreatedashortageofnaturalgas.無謂損失是多少?Whatwasthedeadweightloss?Chapter9Slide14供給Supply:QS

=14+2PG+0.25PO單位:萬億立方英尺intrillioncubicfeet(Tcf)需求Demand:QD=-5PG+3.75PO需求量Quantitydemanded(Tcf)PG=天然氣價(jià)格:美元/千立方英尺($/mcf)

PO

=石油價(jià)格:美元/桶($/b).價(jià)格控制和天然氣短缺PriceControlsand

NaturalGasShortages1975年的數(shù)據(jù)Datafor1975Chapter9Slide15PO=$8/b均衡價(jià)格PG=$2/mcf,均衡數(shù)量Q=20Tcf價(jià)格上限1美元上述信息可圖示:價(jià)格控制和天然氣短缺PriceControlsand

NaturalGasShortages1975年的數(shù)據(jù)

Datafor1975Chapter9Slide16BA2.40C消費(fèi)者所得是A

長方形減B三角形,生產(chǎn)者所失是A

長方形加C三角形.SD2.00Quantity(billionmcf)0Price($/mcf)1520253018(Pmax)1.00價(jià)格控制和天然氣短缺PriceControlsand

NaturalGasShortages510Chapter9Slide17衡量價(jià)格控制的影響1Tcf=1billionmcfIfQD=18,thenP=$2.40[18=-5PG+3.75(8)]A=(18billionmcf)x($1/mcf)=$18billionB=(1/2)x(2b.mcf)x($0.40/mcf)=$0.4billionC=(1/2)x(2b.mcf)x($1/mcf)=$1billion價(jià)格控制和天然氣短缺PriceControlsand

NaturalGasShortagesChapter9Slide18衡量價(jià)格控制的影響MeasuringtheImpactofPriceControls1975消費(fèi)者剩余的變化Changeinconsumersurplus=A-B=18-0.4=$17.6billion生產(chǎn)者剩余的變化Changeinproducersurplus=-A-C=-18-1=-$19.0billion價(jià)格控制和天然氣短缺PriceControlsand

NaturalGasShortagesChapter9Slide19MeasuringtheImpactofPriceControls用1975年美元,無謂損失14億美元1975dollars,deadweightloss=-B-C=-0.4-1=-$1.4billion用2000年美元,無謂損失每年超過40億美元.In2000dollars,thedeadweightlossismorethan$4billionperyear.價(jià)格控制和天然氣短缺PriceControlsand

NaturalGasShortagesChapter9Slide20競爭性市場的效率TheEfficiencyof

aCompetitiveMarket什么時(shí)候競爭性市場產(chǎn)生一種無效率的資源配置或市場失靈?Whendocompetitivemarketsgenerateaninefficientallocationofresourcesormarketfailure?

Chapter9Slide21競爭性市場的效率TheEfficiencyof

aCompetitiveMarket什么時(shí)候市場失靈? Whenmarketfailure? 1)外部性Externalities成本或收益不作為市場價(jià)格的一部分而出現(xiàn)(如污染)Costsorbenefitsthatdonotshowupaspartofthemarketprice(e.g.pollution)Chapter9Slide22競爭性市場的效率TheEfficiencyof

aCompetitiveMarket什么時(shí)候市場失靈?Whenmarketfailure? 2) 信息缺乏LackofInformation不完全的信息阻礙消費(fèi)者作出效用最大化的決策.Imperfectinformationpreventsconsumersfrommakingutility-maximizingdecisions.Chapter9Slide23政府對(duì)這些市場的干預(yù)能夠提高效率.Governmentinterventioninthesemarketscanincreaseefficiency.沒有市場失靈時(shí),若有政府干預(yù),會(huì)創(chuàng)造出無效率或無謂損失.Governmentinterventionwithoutamarketfailurecreatesinefficiencyordeadweightloss.競爭性市場的效率TheEfficiencyof

aCompetitiveMarketChapter9Slide24P1Q1ABC當(dāng)規(guī)定價(jià)格不得高于P1時(shí),導(dǎo)致無謂損失為B三角形和C三角形.當(dāng)價(jià)格被置于市場出清水平之下時(shí)的福利損失

WelfareLossWhenPriceIsHeldBelowMarket-ClearingLevelQuantityPriceSDP0Q0Chapter9Slide25P2Q3ABCQ2若QS=Q2無謂損失是多少?當(dāng)規(guī)定價(jià)格不得低于P2時(shí)需求量僅為Q3.無謂損失為B三角形和C三角形當(dāng)價(jià)格被置于市場出清水平之上時(shí)的福利損失

WelfareLossWhenPriceIsHeldAboveMarket-ClearingLevelQuantityPriceSDP0Q0Chapter9Slide26人腎市場TheMarketforHumanKidneys1984年”國家器官移植法”禁止出售器官用作移植.The1984NationalOrganTransplantationActprohibitsthesaleoforgansfortransplantation.分析該法案的影響供給:QS=8,000+0.2P若P

=$20,000,Q=12,000需求:QD=16,000-0.2PChapter9Slide27D當(dāng)S受限制時(shí),A加D衡量腎臟總價(jià)值.ACA和C為供方的損失.TheMarketforKidneys,andEffects

ofthe1984OrganTransplantationActQuantityPrice8,0004,0000$10,000$30,000$40,000S’1984年的法案有效地使價(jià)格為零.The1984acteffectivelymakesthepricezero.B若價(jià)格為0,則消費(fèi)者得益為A減B.SD12,000$20,000Chapter9Slide28法案限制使供給量(捐獻(xiàn))為8,000.

Theactlimitsthequantitysupplied(donations)to8,000.供方剩余的損失:Losstosuppliersurplus:A+C=(8,000)($20,000)+(1/2)(4,000)($20,000)=$200/m.人腎市場

TheMarketforHumanKidneysChapter9Slide29接受方受益:Gaintorecipients:A-B=(8,000)($20,000)-(1/2)(4,000)($20,000)=$120/m.無謂損失:Deadweightloss:B+C或$200million-$120million=$80million人腎市場

TheMarketforHumanKidneysChapter9Slide30其他無效率的成本OtherInefficiencyCost 1) 不一定配置給評(píng)價(jià)最高的人.Allocationisnotnecessarilytothosewhovaluethekidney’sthemost. 2) 支付價(jià)格提高到均衡價(jià)格4萬美元,醫(yī)院得到這個(gè)價(jià)格.Pricemayincreaseto$40,000,theequilibriumprice,withhospitalsgettingtheprice.人腎市場

TheMarketforHumanKidneysChapter9Slide31贊成禁止出售器官的論點(diǎn):Argumentsinfavorofprohibitingthesaleoforgans: 1) 出售者健康情況的隱瞞引起的信息不完全I(xiàn)mperfectinformationaboutdonor’s healthandscreening人腎市場

TheMarketforHumanKidneysChapter9Slide32 2) 根據(jù)支付能力分配是不公平的Unfairtoallocateaccordingtotheabilitytopay把價(jià)格置于均衡之下必然創(chuàng)造短缺Holdingpricebelowequilibriumwillcreateshortages器官與人造替代品(為何區(qū)別對(duì)待)Organsversusartificialsubstitutes贊成禁止出售器官的論點(diǎn):

Argumentsinfavorofprohibitingthesaleoforgans:Chapter9Slide33最低價(jià)格MinimumPrices有時(shí),政府政策力求把價(jià)格提高到市場出清水平之上.Periodicallygovernmentpolicyseekstoraisepricesabovemarket-clearinglevels.通過價(jià)格下限和最低工資,我們對(duì)此進(jìn)行考察.Wewillinvestigatethisbylookingatapricefloorandtheminimumwage.Chapter9Slide34BA生產(chǎn)者剩余的變化是A-C-D.生產(chǎn)者境況惡化.CD最低價(jià)格PriceMinimumQuantityPriceSDP0Q0PminQ3Q2若生產(chǎn)者生產(chǎn)Q2,數(shù)量Q2-Q3賣不出去.Chapter9Slide35最低工資(2006-08-11)

（廈門日?qǐng)?bào)）本報(bào)訊（記者李曉平通訊員陳相秋）昨日，記者從市勞動(dòng)和社會(huì)保障局獲悉，我市企業(yè)最低工資標(biāo)準(zhǔn)已獲省政府批準(zhǔn)，2006—2007年島內(nèi)（即思明區(qū)、湖里區(qū)）企業(yè)最低工資上調(diào)為每人每月650元，比上一年度提高了50元；集美區(qū)、海滄區(qū)為每人每月600元，比上一年度提高了50元；同安區(qū)、翔安區(qū)企業(yè)最低工資標(biāo)準(zhǔn)為每人每月550元，比上一年度提高了70元。Chapter9Slide36BB和C三角形給出無謂損失.CAwminL1L2Unemployment廠商不得付少于wmin的工資.這導(dǎo)致失業(yè).SDw0L0最低工資TheMinimumWageLwChapter9Slide37航線管制AirlineRegulation在1976-1981間,美國航空行業(yè)激烈變革.During1976-1981theairlineindustryintheU.S.changeddramatically.放棄管制導(dǎo)致行業(yè)的重大變化.Deregulationleadtomajorchangesintheindustry.隨著新航空公司的進(jìn)入,一些航空公司合并或退出經(jīng)營.Someairlinesmergedorwentoutofbusinessasnewairlinesenteredtheindustry.Chapter9Slide38BAC解除管制之后:價(jià)格降至PO.消費(fèi)者剩余的變化是A+B.Q3D面積D

是賣不出產(chǎn)出的成本.民航委員會(huì)航線管制的結(jié)果

EffectofAirlineRegulationbytheCivilAeronauticsBoardQuantityPriceSDP0Q0Q1PminQ2在管制時(shí),價(jià)格是Pmin

需求量QD=Q1,供給量Qs=Q2.航空業(yè)數(shù)據(jù)AirlineIndustryData航空公司數(shù)量Numberofcarriers 33 72 86 60 86 96載客率Passengerloadfactor(%) 54 59 61 62 67 69乘客里程比率 (按1995年不變價(jià)美元) .218 .210 .166 .150 .129 .126實(shí)際成本指數(shù)(1995=100) 101 122 111 107 100 99剔除燃料成本上升后的

實(shí)際成本指數(shù) 94 98 98 100 100 98 1975 1980 1985 1990 1995 1996Chapter9Slide40航空業(yè)數(shù)據(jù)AirlineIndustryData航空業(yè)數(shù)據(jù)表明(5點(diǎn)):Airlineindustrydatashow: 1) 長期調(diào)整:隨著航空公司數(shù)量的增加,價(jià)格下降Long-runadjustmentasthenumberofcarriersincreasedandpricesdecreased 2) 較高的載客率顯示較高的效率HigherloadfactorsindicatingmoreefficiencyChapter9Slide41航空業(yè)數(shù)據(jù)AirlineIndustryDataAirlineindustrydatashow: 3) 下降的比率(每乘客/英里收入)Fallingrates 4) 實(shí)際成本略有上升(調(diào)整燃油成本后)Realcostincreasedslightly(adjustedfuelcost) 5)大的福利收益LargewelfaregainChapter9Slide42價(jià)格支持和生產(chǎn)配額

PriceSupportsandProductionQuotas美國的農(nóng)業(yè)政策建立在價(jià)格支持制度之上.Muchofagriculturalpolicyisbasedonasystemofpricesupports.支持價(jià)格定于均衡價(jià)格之上,政府購買剩余產(chǎn)品.Thisissupportpriceissetabovetheequilibriumpriceandthegovernmentbuysthesurplus.這常與減產(chǎn)或限產(chǎn)的激勵(lì)結(jié)合在一起ThisisoftencombinedwithincentivestoreduceorrestrictproductionChapter9Slide43BDA為維持價(jià)格Ps政府購買數(shù)量Qg.消費(fèi)者剩余變化=-A-B,生產(chǎn)者剩余變化A+B+DD+QgQg價(jià)格支持PriceSupportsQuantityPriceSDP0Q0PsQ2Q1Chapter9Slide44D+QgQgBA價(jià)格支持PriceSupportsQuantityPriceSDP0Q0PsQ2Q1政府的成本是斑點(diǎn)矩形Ps(Q2-Q1)D總的福利損失總福利損失TotalwelfarelossD-(Q2-Q1)psChapter9Slide45價(jià)格支持PriceSupports問題：Question:存在更有效的辦法讓農(nóng)民增加A+B+D收入嗎？Isthereamoreefficientwaytoincreasefarmer’sincomebyA+B+D?P263：直接發(fā)錢社會(huì)可節(jié)約(Q2-Q1)ps-D。Chapter9Slide46生產(chǎn)配額ProductionQuotas通過減少供給，政府也可引起價(jià)格上升。Thegovernmentcanalsocausethepriceofagoodtorisebyreducingsupply.價(jià)格支持和生產(chǎn)配額

PriceSupportsandProductionQuotasChapter9Slide47下列2項(xiàng)有什么影響：Whatistheimpactof: 1) 控制進(jìn)入出租車市場？Controllingentryintothetaxicabmarket? 2) 控制售酒許可證數(shù)量？Controllingthenumberofliquorlicenses?價(jià)格支持和生產(chǎn)配額

PriceSupportsandProductionQuotasChapter9Slide48BACS減少A+BPS變化=A-C無謂損失=B+CCD供給限制SupplyRestrictionsQuantityPriceDP0Q0SPSS’Q1供給限制到Q1供給移動(dòng)到S’@Q1Q2Chapter9Slide49BACD供給限制SupplyRestrictionsQuantityPriceDP0Q0SPSS’Q1政府用激勵(lì)（獎(jiǎng)金）維持Ps

政府的成本=B+C+DQ2Chapter9Slide50供給限制SupplyRestrictionsBAQuantityPriceDP0Q0PSSS’DC=A-C+B+C+D=A+B+D。（生產(chǎn)者剩余總變化）生產(chǎn)者和消費(fèi)者剩余正好與價(jià)格支持相同（上例）.=-A-B+A+B+D-B-C-D=-B-C.（福利總變化）Q1Q2Chapter9Slide51供給限制SupplyRestrictions問題Questions:政府如何能夠降低成本又仍然補(bǔ)貼農(nóng)民？Howcouldthegovernmentreducethecostandstillsubsidizethefarmer?價(jià)格支持和限耕方案，哪種成本更高？Whichismorecostly:supportsoracreagelimitations?BAQuantityPriceDP0Q0PSSS’DCQ1Q2Chapter9Slide52供給限制SupplyRestrictions價(jià)格支持>限耕方案(Q2-Q1)ps>BCD限耕方案>直接發(fā)錢限耕方案損失：-B-C直接發(fā)錢損失；0農(nóng)民得到ABD政府付出ABD（P264）BAQuantityPriceDP0Q0PSSS’DCQ2Q1Chapter9Slide53小麥的價(jià)格支持

SupportingthePriceofWheat1981供給Supply:Qs=1,800+240P需求Demand:QD=3,550-266P均衡價(jià)格和數(shù)量是$3.46和2,630millionbushels Equilibriumpriceandquantitywas$3.46and2,630millionbushelsChapter9Slide54小麥的價(jià)格支持

SupportingthePriceofWheat1981價(jià)格支持定在$3.70

Pricesupportwassetat$3.70QD+QG=QDT=3,440-266P+QGQS=QD1,800+240P=3,550-266P+QGQG=506P-1,750QG=(506)(3.70)-175=122millionbushelsChapter9Slide55D+Qg通過購買122millionbushels政府提高了市場出清價(jià)格.P0=$3.702,5662,688ABCQgAB消費(fèi)者損失ABC生產(chǎn)者得益SDP0=$3.462,6301,8001981年的小麥?zhǔn)袌?/p>

TheWheatMarketin1981QuantityPriceChapter9Slide56小麥的價(jià)格支持

SupportingthePriceofWheat1981消費(fèi)者剩余的變化Thechangeinconsumersurplus=(-A-B)A=(3.70-3.46)(2,566)=$616millionB=(1/2)(3.70-3.46)(2,630-2,566)=$8million消費(fèi)者剩余的變化Changeinconsumersurplus:-$624million.Chapter9Slide57小麥的價(jià)格支持

SupportingthePriceofWheat1981政府的成本Costtothegovernment:$3.70x122millionbushels=$452million總成本=$624+452=$1,076million總得益Totalgain=A+B+C=$638million政府也支付30cents/bushel=$806millionChapter9Slide58小麥的價(jià)格支持

SupportingthePriceofWheat在1985年，出口需求下降，小麥出清價(jià)格降到$1.80/bushel。In1985,exportdemandfellandthemarketclearingpriceofwheatfellto$1.80/bushel.Chapter9Slide59小麥的價(jià)格支持

SupportingthePriceofWheat1985Supply:QS=1,800+240P1986Demand:QD=2580-194PQS=QD

at$1.80and22.32億bushelsPS=$3.20為維持$3.20/bushel的價(jià)格，政府規(guī)定生產(chǎn)配額為24.25億bushels。Tomaintain$3.20/bushelaproductionquotaof2,425millionbushelswasimposedChapter9Slide60小麥的價(jià)格支持

SupportingthePriceofWheat1985政府購買GovernmentPurchase:2,425=2,580-194P+QGQG=-155+194PP=$3.20–支持價(jià)格thesupportpriceQG=-155+194($3.20)=466millionbushelsChapter9Slide611985年的小麥?zhǔn)袌?/p>

TheWheatMarketin1985QuantityPrice1,800SDP0=$1.802,232為把價(jià)格提高到$3.20,政府購買466millionbushels,并規(guī)定生產(chǎn)配額為2,425million

bushels.D+QSS’P0=$3.201,9592,425QSChapter9Slide62小麥的支持價(jià)格

SupportingthePriceofWheat1985政府購買GovernmentPurchase:

政府成本Governmentcost=$3.20x466=$1,491million80cent補(bǔ)貼subsidy=.80x2,425=$1,940million總成本Totalcost=$3.5billionChapter9Slide63小麥的支持價(jià)格

SupportingthePriceofWheat問題Question:生產(chǎn)者和消費(fèi)者剩余的變化是多少?Whatisthechangeinconsumerandproducersurplus?Chapter9Slide64小麥的支持價(jià)格

SupportingthePriceofWheat1996年的”農(nóng)民自由”1996FreedomtoFarm減少價(jià)格支持和配額直到2003年,國會(huì)再次通過后1996年法案重新生效.Reducespricesupportsandquotasuntil2003whentheygobackintoeffectunderthe1996law.Chapter9Slide65小麥的支持價(jià)格

SupportingthePriceofWheat1998年的小麥?zhǔn)袌?998WheatMarketP=$2.65QD=3244-283PQS

=1944+207PQ=2493政府補(bǔ)貼Governmentsubsidyof.66/bushelor$1.6billionEXAMPLE9.5WHYCAN’TIFINDATAXI?ThecityofNewYorklimitsthenumberoftaxisbyrequiringeachtaxitohaveamedallion(essentiallyapermit),andthenlimitingthenumberofmedallions.In2011therewere13,150medallionsinNewYork—roughlythesamenumberasin1937.Whynotjustissuemoremedallions?Thereasonissimple.Doingsowouldincurthewrathofthecurrentownersofmedallions.Medallionscanbeboughtandsoldbythecompaniesthatownthem.In1937,therewereplentyofmedallionstogoaround,sotheyhadlittlevalue.By1947,thevalueofamedallionhadincreasedto$2,500,by1980to$55,000,andby2011to$880,000.That’sright—becauseNewYorkCitywon’tissuemoremedallions,thevalueofataximedallionisapproaching$1million!Butofcoursethatvaluewoulddropsharplyifthecitystartingissuingmoremedallions.SotheNewYorktaxicompaniesthatcollectivelyownthe13,150availablemedallionshavedoneeverythingpossibletopreventthecityfromissuinganymore—andhavesucceededintheirefforts.Ifthecityweretoissueanother7,000medallionsforatotalofabout20,000,demandandsupplywouldequilibrateatapriceofabout$350,000permedallion–stillalot,butjustenoughtoleasecabs,runataxibusiness,andstillmakeaprofit.EXAMPLE9.5WHYCAN’TIFINDATAXI?TAXIMEDALLIONSINNEWYORKCITYFIGURE9.13ThedemandcurveDshowsthequantityofmedallionsdemandedbytaxicompaniesasafunctionofthepriceofamedallion.ThesupplycurveSshowsthenumberofmedallionsthatwouldbesoldbycurrentownersasafunctionofprice.NewYorklimitsthequantityto13,150,sothesupplycurvebecomesverticalandintersectsdemandat$880,000,themarketpriceofamedallionin2011.ImportQuotasandTariffs9.5●importquota Limitonthequantityofagoodthatcanbeimported.IMPORTTARIFFORQUOTATHATELIMINATESIMPORTSFIGURE9.14●tariff Taxonanimportedgood.Inafreemarket,thedomesticpriceequalstheworldpricePw.AtotalQdisconsumed,ofwhichQsissupplieddomesticallyandtherestimported.Whenimportsareeliminated,thepriceisincreasedtoP0.ThegaintoproducersistrapezoidA.ThelosstoconsumersisA+B+C,sothedeadweightlossisB+C.IMPORTTARIFFORQUOTA(GENERALCASE)FIGURE9.15Whenimportsarereduced,thedomesticpriceisincreasedfromPwtoP*.Thiscanbeachievedbyaquota,orbyatariffT=P*?Pw.TrapezoidAisagainthegaintodomesticproducers.ThelosstoconsumersisA+B+C+D.Ifatariffisused,thegovernmentgainsD,therevenuefromthetariff.ThenetdomesticlossisB+C.Ifaquotaisusedinstead,rectangleDbecomespartoftheprofitsofforeignproducers,andthenetdomesticlossisB+C+D.EXAMPLE9.6THESUGARQUOTAInrecentyears,theworldpriceofsugarhasbeenbetween10and28centsperpound,whiletheU.S.pricehasbeen30to40centsperpound.Why?Byrestrictingimports,theU.S.governmentprotectsthe$4billiondomesticsugarindustry,whichwouldvirtuallybeputoutofbusinessifithadtocompetewithlow-costforeignproducers.ThispolicyhasbeengoodforU.S.sugarproducers,butbadforconsumers.U.S.production:15.9billionpoundsU.S.consumption:22.8billionpoundsU.S.price:36centsperpoundWorldprice24centsperpoundU.S.supply:QS=7.95+0.66PU.S.demand:QD=29.730.19PAtthe24-centworldprice,U.S.productionwouldhavebeenonlyabout7.9billionpoundsandU.S.consumptionabout25.2billionpounds,ofwhich25.2?7.9=17.3billionpoundswouldhavebeenimported.ButfortunatelyforU.S.producers,importswerelimitedtoonly6.9billionpounds.EXAMPLE9.6THESUGARQUOTASUGARQUOTAIN2010FIGURE9.16Attheworldpriceof24centsperpound,about25.2billionpoundsofsugarwouldhavebeenconsumedofwhichallbut7.9billionpoundswouldhavebeenimported.Restrictingimportsto6.9billionpoundscausedtheU.S.pricetogoupby12cents.Thecosttoconsumers,A+B+C+D,wasabout$2.9billion.ThegaintodomesticproducerswastrapezoidA,about$1.4billion.RectangleD,$836million,wasagaintothoseforeignproducerswhoobtainedquotaallotments.TrianglesBandCrepresentthedeadweightlossofabout$614million.TheImpactofaTaxorSubsidy9.6INCIDENCEOFATAXFIGURE9.17●

specifictaxTaxofacertainamountofmoneyperunitsold.Pbistheprice(includingthetax)paidbybuyers.Psisthepricethatsellersreceive,lessthetax.Heretheburdenofthetaxissplitevenlybetweenbuyersandsellers.BuyersloseA+B.SellersloseD+C.ThegovernmentearnsA+Dinrevenue.ThedeadweightlossisB+C.Marketclearingrequiresfourconditionstobesatisfiedafterthetaxisinplace:QD=QD(Pb) (9.1a)QS=QS(Ps) (9.1b)QD=QS (9.1c)Pb?Ps=t (9.1d)THEEFFECTSOFASPECIFICTAXIMPACTOFATAXDEPENDSONELASTICITIESOFSUPPLYANDDEMAND