chap005UsingSupplyandDemand中級(jí)微觀經(jīng)濟(jì)學(xué)-江西

UsingSupplyandDemandChapter5LaugherCurveQ.Howmanyconservativeeconomistsdoesittaketoscrewinalightbulb?A.None. Ifthegovernmentwouldjustleaveitalone,itwouldscrewitselfin.ThePowerofSupplyandDemandChangesinsupplyanddemandwillchangeequilibriumpriceandquantity.ThePowerofSupplyandDemandAshiftindemandthatmovesthedemandcurvetotherightcausesequilibriumpriceandquantitytorise.ThePowerofSupplyandDemandAshiftinsupplythatmovesthesupplycurvetotheleftcausesequilibriumpricetoriseandequilibriumquantitytofall.Price(percassette)AS0Quantityofcassettes(perweek)$2.502.2509810ExcessdemandD1AShiftinDemandD0BAAShiftinSupplyPrice(percassette)Quantityofcassettes(perweek)$2.502.2509810D0S1S0CBExcessdemandSixRealWorldExamplesofSupplyandDemandSupplyanddemandcanshedlightonavarietyofreal-worldevents:Floridafreeze.Financialassetsandthebabyboomers.Tenpercentexcisetax.RiceinIndonesia.Farmlaborers.Christmastoys.FloridaFreezeThecrop-damagingfreezeshiftedthesupplycurvetotheleft.Attheoriginalprice,quantitydemandedexceededquantitysupplied.Priceroseuntilthequantitydemandedequaledthequantitysupplied.FloridaFreezeDemandS0(c)P1QeP0QDQSS1FinancialAssetsandtheBabyBoomersDemographicchangesamongbabyboomersmovedthedemandcurveforfinancialassetstotheright.Attheoriginalprice,quantitydemandedexceededquantitysupplied.Priceroseuntilthequantitydemandedequaledthequantitysupplied.FinancialAssetsandtheBabyBoomersS(f)D0P1Q1Q0P0D1QDFinancialAssetsandtheBabyBoomersThesamephenomenonoccurredinthesurgingdemandforhousingamongthisgroupduringthe1980s.ExciseTaxesCongressimposeda10percentsurtaxonluxuryboats.ExciseTaxesA10percentsurtaxonluxuryboatsleviedonsuppliersshiftsthesupplycurvetotheleft.Afterthetaxisimposed,thequantityofboatsdemandeddrops.ExciseTaxesS0D0P1Q1P0Q0S1QDRiceinIndonesiaDrought,pestilence,andthefinancialcrisisshiftedthesupplycurvetotheleft.Thesteepdemandcurvemeansthatthequantitydemandeddoesnotchangemuchwithchangesinprice.RiceinIndonesiaRespondingtohighprices,thegovernmentimportedriceanddistributedittothemarket,causingthesupplycurvetoshifttotheright.RiceinIndonesia(a)S0DemandP1Q1P2Q2P0Q0S1S2FarmLaborersThecompressedharvestingseasonincreasedthedemandandincreasedINSpatrolsdecreasedsupply.Demandshiftedtotherightandsupplyshiftedtotheleft.FarmLaborersAttheoriginalprice,thequantityofworkersdemandedexceededthequantitysupplied.FarmLaborersPricerisesuntilthequantitydemandedequaledthequantitysupplied.FarmLaborersTheeffectonthenumberoflaborershireddependedontherelativesizeofthesupplyshift.FarmLaborers(b)S0D0P1S1D1P0QeChristmasToysAChristmascrazeforFurbiesshiftsdemandtotheright.Ashortageensuedalongwithablackmarket.ChristmasToysFinallythesupplierproducedmore,shiftingthesupplycurvetotheright,causingthepricetodrop.ChristmasToys(d)P1P0QS0S0D0S1D1QD0QD1AReviewGovernmentInterferencesBuyerslooktogovernmentforwaystoholdpricesdown.Sellerslooktogovernmentforwaystoholdpricesup.PriceCeilingsApriceceilingisagovernment-imposedlimitonhowhighapricecanbecharged.RentControlsRentcontrolisapriceceilingonrentssetbygovernment.AnexampleisrentcontrolinParisfollowingWorldWarIandWorldWarII.RentControlsThefollowingweretheconsequencesofrentcontrolinParis:Ahugeshortageoflivingquarters.Newhousingconstructionstopped.Existinghousingwasallowedtodeteriorate.RentControlsThefollowingweretheconsequencesofrentcontrolinParis:Formany,theonlywaytogetlivingquarterswastoofferahugebribetothelandlord.Manyfamilieshadtodoubleupwithotherfamilymembers.RentControlsQSQDSupplyDemandRentalPrice(permonth)Quantityofapartments2.50$17.00ShortageRentControlsAsimilarsituationoccurredinNewYorkCity.AlloftheconsequencesofrentcontrolinParis(callednon-pricerationing)haveoccurredinNewYorkCity.Inaddition,preferencesbasedupongender,race,andothercharacteristicsoftenants,althoughillegal,arebroughtintoplay.PriceFloorsApricefloorisagovernment-imposedlimitonhowlowapricecanbecharged.MinimumWageTheminimumwageisanexampleofapricefloor.Aminimumwageissetbygovernmentspecifyingthelowestwageafirmcanlegallypayanemployee.MinimumWageTheminimumwagecreateswinnersandlosers:Thosewhocanfindworkearnahigherwage.Othersbecomeunemployed.Productioncostsincrease.Consumerspayhigherprices.MinimumWageEconomistsdisagreeabouttheeffectsoftheminimumwage.Taxes,Tariffs,andQuotasAnexcisetaxisataxthatisleviedonaspecificgood.Atariffisanexcisetaxonanimportedgood.Taxesandtariffsraisepricesandreducequantity.TheEffectofanExciseTaxonPriceandQuantityA10percentluxurytaxonexpensiveboatswasimposedin1990.TheEffectofanExciseTaxonPriceandQuantityBecausetheluxurytaxwasimposedontheboatbuilders,thesupplycurvemovedupbytheamountofthetax.TheEffectofanExciseTaxonPriceandQuantityAtapriceequaltotheoriginalpriceplusthetaxtherewasexcesssupply.Thepriceforboatsrosebylessthanthetax,whilequantitysuppliedanddemandedfell.65,000510S1420$70,000DS0Quantityofluxuryboats0PriceofluxuryboatsTheEffectofanExciseTaxonPriceandQuantityThesupplycurveshiftsupbythe$10,000tax60,000600TheEffectofanExciseTaxonPriceandQuantityThetaxwasrepealedin1993becauseoftaxrevenueshortfalls.QuantityRestrictions:QuotasAquotaisaquantitativerestrictionontheamountthatonenationcanexporttoanother.QuantityRestrictions:QuotasTheU.S.governmentrestrictedimportsofJapanesecars.TheeffectwastoraisethepricesJapaneseautomobilesintheU.S.5SupplyDemand9,0008$17,0006,000Japaneseexportsofcars(inmillions)QuantityRestrictions:QuotasQuotaTheRelationshipBetweenaQuotaandaTariffTariffsandquotascanbothbeusedtoreducequantityandraiseprices.TheRelationshipBetweenaQuotaandaTariffThereisadifferencebetweenimposingatariffandimposingaquota.Inthecaseofaquota,theprofitsfromahigherpricegoestothemanufacturer.Inthecaseofthetariff,thetaxgoestothegovernment.TheRelationshipBetweenaQuotaandaTariffAsaconsequence,oncequotasareinstituted,Japanesefirmscompetedintenselytogetthem.TheRelationshipBetweenaQuotaandaTariffJapaneseexportsofcarsS1DemandPriceofJapanesecarsS0Tariffrevenue9,0008$11,0006,000$17,0005TheLimitationsOfSupplyAndDemandAnalysisItisnotenoughtobeabletoexplainwhathappenswhensupplyordemandcurvesshift.Itisnecessarytounderstandtheassumptionsunderlyingtheanalysis.TheLimitationsOfSupplyAndDemandAnalysisOtherthingsdon'tremainconstant.Sometimessupplyanddemandareinterconnected.Supply/demandanalysisisthefirststeptoanalysis,notthecompleteanalysis.TheLimitationsOfSupplyAndDemandAnalysisDecidingwhethertheeffectsaresignificanttoconsiderrequiresaknowledgeofthestructureoftheeconomybecauseallactionshaverippleorfeedbackeffects.TheLimitationsOfSupplyAndDemandAnalysisTheother-things-constantassumptionislikelynottoholdtruewhenonethegoodsrepresentalargepercentageoftheentireeconomy.TheFallacyofCompositionThefallacyofcompositionisthefalseassumptionthatwhatistrueforapartwillalsobetrueforthewhole.TheFallacyofCompositionThousandsofsmalleffectstakentogetheradduptoalargeeffect.TheFallacyofCompositionWhenanalyzingtheaggregate,smalleffectsthatcanbeputasideinmicro,canaddup,andhencecannotbeforgotten.TheFallacyofCompositionSmalleffectscomprisemicroeconomicswhilelargeeffectscomprisemacroeconomics.TheRolesofGovernmentProvideastableinstitutionalframework.Promoteeffectiveandworkablecompetition.Correctforexternalities.Ensureeconomicstabilityandgrowth.Provideforpublicgoods.Adjustforundesiredmarketresults.ProvideaStableSetofInstitutionsandRulesOnlythegovernmentcancreateastableenvironmentandenforcecontractsthroughitslegalsystem.ProvideaStableSetofInstitutionsandRulesWhengovernmentsdonotprovideastableenvironment,asisnowhappeninginRussia,economicgrowthisdifficult-usuallysucheconomiesarestagnant.PromoteEffectiveandWorkableCompetitionGovernmentpromotescompetitionandprotectagainstmonopolies.MonopolypoweristheabilityofindividualsorfirmscurrentlyinbusinesstopreventotherindividualsorfirmsfromenteringthesamekindofbusinessPromoteEffectiveandWorkableCompetitionMonopolypowergivesexistingfirmsorindividualsthepowertoraiseprices.PromoteEffectiveandWorkableCompetitionManyplayersinthemarketinsistonopencompetitionexceptwhenitcomestothemselves:Farmerslikecompetitionbutstillwantpricesupports.Lawyersandarchitectslikecompetitionbutstillwantlicensingtopreventothersfromenteringthemarket.CorrectforExternalitiesUnlesstheyarerequiredtodoso,partiestoanyexchangeareunlikelytotakeintoaccountanyexternality.CorrectforExternalitiesAnexternalityistheeffectthatanactionmayhaveonathirdpartythatthepersonwhoundertookthatactiondidnottakeintoaccount.CorrectforExternalitiesTheexternalitymaybepositiveinwhichcasesocietybenefitsevenmorethanthetwoparties–anexampleiseducation.CorrectforExternalitiesTheexternalitymaybenegativeinwhichcasesocietyasawholebenefitslessthanthetwoparties–anexampleispollution.CorrectforExternalitiesWhenthereareexternalities,governmenthasthepotentialroletochangetherulessothatthepartiesmusttakeintoaccounttheeffectoftheiractionsonothers.EnsureEconomicStabilityandGrowthMostAmericansagreethatgovernmentshould:Preventlargefluctuationsineconomicactivity.Maintainarelativelyconstantpricelevel.Provideaneconomicenvironmentconducivetoeconomicgrowth.EnsureEconomicStabilityandGrowthMosteconomistssupportthesegoalssincetheyinvolvemacroeconomicexternalities.Macroeconomicexternalitiesareexternalitiesthataffectthelevelsofunemployment,inflation,andgrowthintheeconomyasawhole.ProvideforPublicGoodsPublicgoodsarethosewhoseconsumptionbyoneindividualdoesnotpreventtheirconsumptionbyotherindividuals–anexampleisapublicpark.ProvideforPublicGoodsIncontrast,aprivategoodisonethat,whenconsumedbyoneindividual,cannotbeconsumedbyotherindividuals–anexampleisanapple.ProvideforPublicGoodsAfreeriderisapersonwhoparticipatesinsomethingwithouthavingtopayforit.ProvideforPublicGoodsSincemosteveryonewouldenjoyhavingpublicparkswithouthavingtopayforthem,governmentrequiresthatthepublicbetaxedtopayforpublicparks,therebyeliminatingfreeriders.AdjustforUndesiredMarketResultsInanattempttomakethemarketfairer,thegovernment,throughtaxesandexpenditures,redistributesincomeamonghouseholds.Theresultiscontroversy.AdjustforUndesiredMarketResultsForexample,intryingtobefair,whichtypeoftaxshouldthegovernmentuse?AdjustforUndesiredMarketResultsAprogressivetax,suchastheU.S.incometaxisonewhoseratesincreaseasaperson'sincomeincreases.AdjustforUndesiredMarketResultsAregressivetaxsuchasasalestaxisonewhoseeffectdecreaseasincomerises.AdjustforUndesiredMarketResultsAproportionaltax,suchastheSocialSecuritytax,isonewhoseratesareconstantatallincomelevels,regardlessofthetaxpayer'stotalannualincome.AdjustforUndesiredMarketResultsAnothercontrove