曼昆微观经济学课后练习进步英文规范标准答案(第七章)

1、kets7CONSUMERS,PRODUCERS,ANDTHEEFFICIENCYOFMARKETSWHAT'SNEWINTHESIXTHEDITION:Therearenomajorchangestothischapter.LEARNINGOBJECTIVES:Bytheendofthischapter,studentsshouldunderstand:thelinkbetweenbuyers'willingnesstopayforagoodandthedemandcurve.howtodefineandmeasureconsumersurplus.thelinkbetwee

2、nsellers'costsofproducingagoodandthesupplycurve.howtodefineandmeasureproducersurplus.thattheequilibriumofsupplyanddemandmaximizestotalsurplusinamarket.CONTEXTANDPURPOSE:121?2021CengageLearning.AllRightsReserved.Maynotbescanned,copiedorduplicated,orpostedtoapubliclyaccessiblewebsite,inwholeorinpa

3、rt.Chapter7isthefirstchapterinathree-chaptersequenceonwelfareeconomicsandmarketefficiency.Chapter7employsthesupplyanddemandmodeltodevelopconsumersurplusandproducersurplusasameasureofwelfareandmarketefficiency.TheseconceptsarethenutilizedinChapters8and9todeterminethewinnersandlosersfromtaxationandres

4、trictionsoninternationaltrade.ThepurposeofChapter7istodevelopwelfareeconomicsthestudyofhowtheallocationofresourcesaffectseconomicwell-being.Chapters4through6employedsupplyanddemandinapositiveframework,whichfocusedonthequestion,“Whatistheequilibriumpriceandquantityinamarket?Thischapternowaddressesthe

5、normativequestion,“Istheequilibriumpriceandquantityinamarketthebestpossiblesolutiontotheresourceallocationproblem,orisitsimplythepriceandquantitythatbalancesupplyanddemand?Studentswilldiscoverthatundermostcircumstancestheequilibriumpriceandquantityisalsotheonethatmaximizeswelfare.KEYPOINTS:Consumers

6、urplusequalsbuyerswillingnesstopayforagoodminustheamounttheyactuallypayforit,anditmeasuresthebenefitbuyersgetfromparticipatinginamarket.Consumersurpluscanbecomputedbyfindingtheareabelowthedemandcurveandabovetheprice.Producersurplusequalstheamountsellersreceivefortheirgoodsminustheircostsofproduction

7、,anditmeasuresthebenefitsellersgetfromparticipatinginamarket.Producersurpluscanbecomputedbyfindingtheareabelowthepriceandabovethesupplycurve.Anallocationofresourcesthatmaximizesthesumofconsumerandproducersurplusissaidtobeefficient.Policymakersareoftenconcernedwiththeefficiency,aswellastheequality,of

8、economicoutcomes.Theequilibriumofsupplyanddemandmaximizesthesumofconsumerandproducersurplus.Thatis,theinvisiblehandofthemarketplaceleadsbuyersandsellerstoallocateresourcesefficiently.Marketsdonotallocateresourcesefficientlyinthepresenceofmarketfailuressuchasmarketpowerorexternalities.CHAPTEROUTLINE:

9、I.Definitionofwelfareeconomics:thestudyofhowtheallocationofresourcesaffectseconomicwell-being.Studentsoftenareconfusedbytheuseofthewordaretalkingaboutsocialwell-beingandnotpublicassistance.welfare.emindthemthatweII.ConsumerSurplusA.WillingnesstoPay1. Definitionofwillingnesstopay:themaximumamountthat

10、abuyerwillpayforagood.sfirstalbum.2. Example:Youareauctioningamint-conditionrecordingofElvisPresleyFourbuyersshowup.Theirwillingnesstopayisasfollows:StudentswillunderstandconsumersurplusifyoutakethetimetoworkthroughtheElvisPresleyexample.Ifyoustartwiththissimpleexample,studentswillhavenotroubleunder

11、standinghowtofindconsumersurplusonagraph.Table1BuyerW川ingnesstoPayJohn$100Paul$80George$70Ringo$50Ifthebiddinggoestoslightlyhigherthan$80,allbuyersdropoutexceptforJohn.BecauseJohniswillingtopaymorethanhehastoforthealbum,hederivessomebenefitfromparticipatinginthemarket.3. Definitionofconsumersurplus:

12、theamountabuyeriswillingtopayforagoodminustheamountthebuyeractuallypaysforit.4. Notethatifyouhadmorethanonecopyofthealbum,thepriceintheauctionwouldActivity1ValueofaTimeMachineType:Topics:Materialsneeded:Time:Classlimitations:In-classdemonstrationConsumersurplusNone10minutesWorksinanysizeclassPurpose

13、Consumersurpluscanbeahardconceptforstudentsbecauseitisbasedonavoidedexpenseratherthanonmoneythatisactuallyexchanged.Thisexampleputsaspecificdollarvalueonconsumersurplus.InstructionsTelltheclass,“Anewtechnologyhasbeendevelopedthatallowsindividualstotravelbackwardorforwardintime.Wewanttoidentifytheval

14、uethistimemachineprovidestoconsumers.Let'sassumethefourconsumerswhomostdesirethisproductareinthisclass.Choosefourstudentnamesandusetheminthefollowingexample:“Scottistheconsumerwhomostvaluesthisproduct.Hewantstogobacktothetimeofthedinosaurs.Heiswillingtopay$3,000.“Carolistheconsumerwiththenexthig

15、hestwillingnesstopay.Shewouldliketosee200yearsinthefuture.She'dpay$2,500.“Steveisthenexthighestbidder.He'dliketorelivethisentiresemester.Heidof$800.“Jeanneisourfourthconsumer.She'dpay$200tomovetheclockforwardtotheethisclassperiod.Ontheboardwrite:Scott$3,000Carol$2,500Steve$800Jeanne$200e

16、ndupbeinglower(alittleover$70inthecaseoftwoalbums)andbothJohnandPaulwouldgainconsumersurplus.Thisrepresentsthedemandcurveforthetimemachine.Consumersurplusisthedifferencebetweenwhatconsumersarewillingtopayandtheamounttheyactuallyhavetopay.Themarketpricewilldeterminewhousesthetimemachineandhowmuchsurp

17、lustheykeep.ttimetravel.“Ifthepriceofatimemachineridewas$500,threerideswouldbesoldonetoScott,onetoCarol,andonetoSteve.Jeanneisnotwillingtopay$500,soshewouldnCarolh“Wecancalculatetheconsumersurplusofthreetimetrips.Scottwouldpay$3,000butonlypays$500,leaving$2,500ofnetbenefits.(Putthesenumbersontheboar

18、d.)benefitsof$2,000.Stevehas$300innetbenefits.Addingupthesenetsavingsgives$4,800inconsumersurplus.PointsforDiscussionTheconsumersurplusdependsonagood'ssellingpriceandthenumberofconsumerswhoarewillingtopurchasethegoodatthatprice.Thelowertheprice,thegreatertheconsumersurplus.B. UsingtheDemandCurve

19、toMeasureConsumerSurplus1. WecanusetheinformationonwillingnesstopaytoderiveademandcurvefortherareElvisPresleyalbum.PriceBuyersQuantityDemandedMorethan$100None0$80to$100John1$70to$80John,Paul2$50to$70John,Paul,George3$50orlessJohn,Paul,George,Ringo4Figure1Price100801!I70r5034Quantity2. Atanygivenquan

20、tity,thepricegivenbythedemandcurvereflectsthewillingnesstopayofthemarginalbuyer.Becausethedemandcurveshowsthebuyers'willingnesstopay,wecanusethedemandcurvetomeasureconsumersurplus.Figure23. Consumersurpluscanbemeasuredastheareabelowthedemandcurveandabovetheprice.C. HowaLowerPriceRaisesConsumerSu

21、rplusFigure31. Aspricefalls,consumersurplusincreasesfortworeasons.a. Thosealreadybuyingtheproductwillreceiveadditionalconsumersurplusbecausetheyarepayinglessfortheproductthanbefore(areaAonthegraph).b. Becausethepriceisnowlower,somenewbuyerswillenterthemarketandreceiveconsumersurplusontheseadditional

22、unitsofoutputpurchased(areaBonthegraph).D.WhatDoesConsumerSurplusMeasure?Itisimportanttostressthatconsumersurplusismeasuredinmonetaryterms.Consumersurplusgivesusawaytoplaceamonetarycostoninefficientmarketoutcomes(duetogovernmentinvolvementormarketfailure).1. Rememberthatconsumersurplusisthedifferenc

23、ebetweentheamountthatbuyersarewillingtopayforagoodandthepricethattheyactuallypay.2. Thus,itmeasuresthebenefitthatconsumersreceivefromthegoodasthebuyersthemselvesperceiveit.ALTERNATIVECLASSROOMEXAMPLE:ReviewthematerialonpriceceilingsfromChapter6.Redrawthemarketfortwo-bedroomapartmentsinyourtown.Drawi

24、napriceceilingbelowtheequilibriumprice.Thengothrough:consumersurplusbeforethepriceceilingisputintoplace.consumersurplusafterthepriceceilingisputintoplace.III. ProducerSurplusA. CostandtheWillingnesstoSell1. Definitionofcost:thevalueofeverythingasellermustgiveuptoproduceagoodYouwillneedtotakesometime

25、toexplaintherelationshipbetweentheproducerswillingnesstosellandthecostofproducingthegood.Therelationshipbetweencostandthesupplycurveisnotasapparentastherelationshipbetweenthedemandcurveandwillingnesstopay.2. Example:Youwanttohiresomeonetopaintyourhouse.Youacceptbidsfortheworkfromfoursellers.Eachpain

26、teriswillingtoworkifthepriceyouwillpayexceedsheropportunitycost.(Notethatthisopportunitycostthusrepresentswillingnesstosell.)Thecostsare:SellerCostMary$900Frida$800Georgia$600Grandma$500Table23. Biddingwillstopwhenthepricegetstobeslightlybelow$600.AllsellerswilldropoutexceptforGrandma.BecauseGrandma

27、receivesmorethanshewouldrequiretopaintthehouse,shederivessomebenefitfromproducinginthemarket.4. Definitionofproducersurplus:theamountasellerispaidforagoodminustheseller'scostofprovidingit.5. Notethatifyouhadmorethanonehousetopaint,thepriceintheauctionwouldendupbeinghigher(alittleunder$800intheca

28、seoftwohouses)andbothGrandmaandGeorgiawouldgainproducersurplus.B. UsingtheSupplyCurvetoMeasureProducerSurplus1. Wecanusetheinformationoncost(willingnesstosell)toderiveasupplycurveforhousepaintingservices.PriceSellersQuantitySupplied$900ormoreMary,Frida,Georgia,Grandma4$800to$900Frida,Georgia,Grandma

29、3$600to$800Georgia,Grandma2$500to$600Grandma1lessthan$500None02. Atanygivenquantity,thepricegivenbythesupplycurverepresentsthecostofthemarginalseller.Becausethesupplycurveshowsthesellers'cost(willingnesstosell),wecanusethesupplycurvetomeasureproducersurplus.Figure4Price900800*,*-*-*600*1500-1234

30、QuantityFigure53. Producersurpluscanbemeasuredastheareaabovethesupplycurveandbelowtheprice.C. HowaHigherPriceRaisesProducerSurplusFigure61. Aspricerises,producersurplusincreasesfortworeasons.a. Thosealreadysellingtheproductwillreceiveadditionalproducersurplusbecausetheyarereceivingmorefortheproductt

31、hanbefore(areaConthegraph).b. Becausethepriceisnowhigher,somenewsellerswillenterthemarketandreceiveproducersurplusontheseadditionalunitsofoutputsold(areaDonthegraph).D. Producersurplusisusedtomeasuretheeconomicwell-beingofproducers,muchlikeALTERNATIVECLASSROOMEXAMPLE:Reviewthematerialonpricefloorsfr

32、omChapter6.Redrawthemarketforanagriculturalproductsuchascorn.Drawinapricesupportabovetheequilibriumprice.Thengothrough:ducersurplusafterthepricesupportisputinplace.Makesurethatyoudiscussthecostofthepricesupporttotaxpayers.consumersurplusisusedtomea

33、suretheeconomicwell-beingofconsumers.PrettyWoman,Chapter6.Vivien(JuliaRoberts)andEdward(RichardGere)negotiateaprice.Afterward,Vivienrevealsshewouldhaveacceptedalowerprice,whileEdwardadmitshewouldhavepaidmore.Ifyouhavedoneagoodjobofintroducingconsumerandproducersurplus,youwillseethelightbulbsgooffabo

34、veyourstudents'headsastheywatchthisclip.IV. MarketEfficiencyA. TheBenevolentSocialPlanner1. Theeconomicwell-beingofeveryoneinsocietycanbemeasuredbytotalsurplus,whichisthesumofconsumersurplusandproducersurplus:TotalSurplus=ConsumerSurplus+ProducerSurplusAmountPaidbyBuyers)+CosttoSellers)TotalSurp

35、lus=(ValuetoBuyers(AmountReceivedbySellersBecausetheAmountPaidbyBuyers=AmountReceivedbySellers:TotalSurplus=ValuetoBuyersCosttoSellers2. Definitionofefficiency:thepropertyofaresourceallocationofmaximizingthetotalsurplusreceivedbyallmembersofsociety.3. Definitionofequality:thepropertyofdistributingec

36、onomicprosperityuniformlythemembersofsociety.Nowmightbeagoodtimetopointoutthatmanygovernmentpoliciesinvolveatrade-offbetweenefficiencyandequity.Whenyouevaluategovernmentpolicies,likepriceceilingsorfloors,youcanexplainthemintermsofequityandefficiency.B. EvaluatingtheMarketEquilibriumFigure 71. Atthem

37、arketequilibriumprice:a. Buyerswhovaluetheproductmorethantheequilibriumpricewillpurchasetheproduct;thosewhodonot,willnotpurchasetheproduct.Inotherwords,thefreemarketallocatesthesupplyofagoodtothebuyerswhovalueitmosthighly,asmeasuredbytheirwillingnesstopay.b. Sellerswhosecostsarelowerthantheequilibri

38、umpricewillproducetheproduct;thosewhosecostsarehigher,willnotproducetheproduct.Inotherwords,thefreemarketallocatesthedemandforgoodstothesellerswhocanproduceitatthelowestcost.2. Totalsurplusismaximizedatthemarketequilibrium.Figure 8Pricea. Atanyquantityofoutputsmallerthantheequilibriumquantity,theval

39、ueoftheproducttothemarginalbuyerisgreaterthanthecosttothemarginalsellersototalsurpluswouldriseifoutputincreases.b. Atanyquantityofoutputgreaterthantheequilibriumquantity,thevalueoftheproducttothemarginalbuyerislessthanthecosttothemarginalsellersototalsurpluswouldriseifoutputdecreases.3. Notethatthis

40、isoneofthereasonsthateconomistsbelievePrinciple#6:Marketsareusuallyagoodwaytoorganizeeconomicactivity.Itwouldbeagoodideatoremindstudentsthattherearecircumstanceswhenthemarketprocessdoesnotleadtothemostefficientoutcome.Examplesincludesituationssuchaswhenafirm(orbuyer)hasmarketpoweroverpriceorwhenther

41、eareexternalitiespresent.Thesesituationswillbediscussedinlaterchapters.C. IntheNews:TicketScalping1. Ticketscalpingisanexampleofhowmarketsworktoachieveanefficientoutcome.2. ThisarticlefromTheBostonGlobedescribeseconomistChipCase'sexperiencewithticketscalping.D. CaseStudy:ShouldThereBeaMarketinOr

42、gans?1. Asamatterofpublicpolicy,peoplearenotallowedtoselltheirorgans.a. Inessence,thismeansthatthereisapriceceilingonorgansof$0.b. Thishasledtoashortageoforgans.2. Thecreationofamarketfororganswouldleadtoamoreefficientallocationofresources,butcriticsworryabouttheequityofamarketsystemfororgans.V.Mark

43、etEfficiencyandMarketFailureA. Toconcludethatmarketsareefficient,wemadeseveralassumptionsabouthowmarketsworked.1. Perfectlycompetitivemarkets.2. Noexternalities.B. Whentheseassumptionsdonothold,themarketequilibriummaynotbeefficient.C. Whenmarketsfail,publicpolicycanpotentiallyremedythesituation.SOLU

44、TIONSTOTEXTPROBLEMS:QuickQuizzes1. Figure1showsthedemandcurveforturkey.ThepriceofturkeyisPiandtheconsumersurplusthatresultsfromthatpriceisdenotedCS.Consumersurplusistheamountabuyeriswillingtopayforagoodminustheamountthebuyeractuallypaysforit.Itmeasuresthebenefittobuyersofparticipatinginamarket.Figur

45、e1Figure22. Figure2showsthesupplycurveforturkey.ThepriceofturkeyisPiandtheproducersurplusthatresultsfromthatpriceisdenotedPS.Producersurplusistheamountsellersarepaidforagoodminusthesellers'costofprovidingit(measuredbythesupplycurve).Itmeasuresthebenefittosellersofparticipatinginamarket.卜PPIusDem

46、andQuantrtyofTurkeyFigure33. Figure3showsthesupplyanddemandforturkey.ThepriceofturkeyisPi,consumersurplusisCS,andproducersurplusisPS.Producingmoreturkeysthantheequilibriumquantitywouldlowertotalsurplusbecausethevaluetothemarginalbuyerwouldbelowerthanthecosttothemarginalselleronthoseadditionalunits.Q

47、uestionsforReview1. Thepriceabuyeriswillingtopay,consumersurplus,andthedemandcurveareallcloselyrelated.Theheightofthedemandcurverepresentsthewillingnesstopayofthebuyers.Consumersurplusistheareabelowthedemandcurveandabovetheprice,whichequalsthepricethateachbuyeriswillingtopayminusthepriceactuallypaid

48、.2. Sellers'costs,producersurplus,andthesupplycurveareallcloselyrelated.Theheightofthesupplycurverepresentsthecostsofthesellers.Producersurplusistheareabelowthepriceandabovethesupplycurve,whichequalsthepricereceivedminuseachseller'scostsofproducingthegood.Figure43. Figure4showsproducerandcon

49、sumersurplusinasupply-and-demanddiagram.4. Anallocationofresourcesisefficientifitmaximizestotalsurplus,thesumofconsumersurplusandproducersurplus.Butefficiencymaynotbetheonlygoalofeconomicpolicymakers;theymayalsobeconcernedaboutequitythefairnessofthedistributionofwell-being.5. Theinvisiblehandofthema

50、rketplaceguidestheself-interestofbuyersandsellersintopromotinggeneraleconomicwell-being.Despitedecentralizeddecisionmakingandself-interesteddecisionmakers,freemarketsoftenleadtoanefficientoutcome.6. Twotypesofmarketfailurearemarketpowerandexternalities.Marketpowermaycausemarketoutcomestobeinefficien

51、tbecausefirmsmaycausepriceandquantitytodifferfromthelevelstheywouldbeunderperfectcompetition,whichkeepstotalsurplusfrombeingmaximized.Externalitiesaresideeffectsthatarenottakenintoaccountbybuyersandsellers.Asaresult,thefreemarketdoesnotmaximizetotalsurplus.ProblemsandApplications1. a.Consumersurplus

52、isequaltowillingnesstopayminusthepricepaid.Therefore,Melissa'swillingnesstopaymustbe$200($120+$80).$90=$110.b. Herconsumersurplusatapriceof$90wouldbe$200c. IfthepriceofaniPodwas$250,Melissawouldnothavepurchasedonebecausethepriceisgreaterthanherwillingnesstopay.Therefore,shewouldreceivenoconsumer

53、surplus.2. IfanearlyfreezeinCaliforniasoursthelemoncrop,thesupplycurveforlemonsshiftstotheleft,asshowninFigure5.TheresultisariseinthepriceoflemonsandadeclineinconsumersurplusfromA+B+CtojustA.SoconsumersurplusdeclinesbytheamountB+C.DemandSIDemandQuantityofLemonsFigure 5QuantrtyofLemonadeFigure 6Inthe

54、marketforlemonade,thehighercostoflemonsreducesthesupplyoflemonade,asshowninFigure6.TheresultisariseinthepriceoflemonadeandadeclineinconsumersurplusfromD+E+FtojustD,alossofE+F.Notethataneventthataffectsconsumersurplusinonemarketoftenhaseffectsonconsumersurplusinothermarkets.3. AriseinthedemandforFren

55、chbreadleadstoanincreaseinproducersurplusinthemarketforFrenchbread,asshowninFigure7.TheshiftofthedemandcurveleadstoC.anincreasedprice,whichincreasesproducersurplusfromareaAtoareaA+B+QiQnQuantityofFrenchBreadFigure7TheincreasedquantityofFrenchbreadbeingsoldincreasesthedemandforflour,asshowninFigure8.

56、Asaresult,thepriceofflourrises,increasingproducersurplusfromareaDtoD+E+F.Notethataneventthataffectsproducersurplusinonemarketleadstoeffectsonproducersurplusinrelatedmarkets.QuantityofFlour4.a.Bertsdemandscheduleis:Figure8PriceQuantityDemandedMorethan$70$5to$71$3to$52$1to$33$1orless4Bert'sdemandc

57、urveisshowninFigure9.1234QuantityofWaterb.c.Figure9Whenthepriceofabottleofwateris$4,Bertbuystwobottlesofwater.HisconsumersurplusisshownasareaAinthefigure.Hevalueshisfirstbottleofwaterat$7,butpaysonly$4forit,sohasconsumersurplusof$3.Hevalueshissecondbottleofwaterat$5,butpaysonly$4forit,sohasconsumersurplusof$1.ThusBert'stotalconsumersurplusis$3+$1=$4,whichistheareaofAinthefigure.Whenthepriceofabottleofwaterfallsfrom$4to$2,Bertbuysthreebottlesofwater,anincreaseo