曼昆经济学原理第七版第10章 外部性课件

Externalities1曼昆经济学原理第七版第10章外部性ExternalitiesGovernmentactioncansometimesimproveuponmarketoutcomesWhymarketssometimesfailtoallocateresourcesefficientlyHowgovernmentpoliciescanpotentiallyimprovethemarket’sallocationWhatkindsofpoliciesarelikelytoworkbest2曼昆经济学原理第七版第10章外部性ExternalitiesExternalityTheuncompensatedimpactofoneperson’sactionsonthewell-beingofabystanderMarketfailureNegativeexternalityImpactonthebystanderisadversePositiveexternalityImpactonthebystanderisbeneficial3曼昆经济学原理第七版第10章外部性ExternalitiesNegativeexternalitiesExhaustfromautomobilesBarkingdogsPositiveexternalitiesRestoredhistoricbuildingsResearchintonewtechnologies4曼昆经济学原理第七版第10章外部性ExternalitiesandMarketInefficiencyWelfareeconomics:arecapDemandcurve:valuetoconsumersPricestheyarewillingtopaySupplycurve:costtosuppliersEquilibriumquantityandpriceEfficientMaximizesthesumofproducerandconsumersurplus5曼昆经济学原理第七版第10章外部性Figure1TheMarketforAluminumPriceofAluminumQuantityofAluminum0Demand(privatevalue)Supply(privatecost)Thedemandcurvereflectsthevaluetobuyers,andthesupplycurvereflectsthecostsofsellers.Theequilibriumquantity,QMARKET,maximizesthetotalvaluetobuyersminusthetotalcostsofsellers.Intheabsenceofexternalities,therefore,themarketequilibriumisefficient.QMARKETEquilibrium6曼昆经济学原理第七版第10章外部性ExternalitiesandMarketInefficiencyNegativeexternalitiesCosttosociety(ofproducingagood)Largerthanthecosttothegoodproducers“AllIcansayisthatifbeingaleadingmanufacturermeansbeingaleadingpolluter,sobeit.”7曼昆经济学原理第七版第10章外部性ExternalitiesandMarketInefficiencyNegativeexternalitiesSocialcostPrivatecostsoftheproducers(supply)PlusthecoststothosebystandersaffectedadverselybythenegativeexternalitySocialcostcurveisabovethesupplycurveTakesintoaccounttheexternalcostsimposedonsociety8曼昆经济学原理第七版第10章外部性Figure2PollutionandtheSocialOptimumPriceofAluminumQuantityofAluminum0Demand(privatevalue)Supply(privatecost)Inthepresenceofanegativeexternality,suchaspollution,thesocialcostofthegoodexceedstheprivatecost.Theoptimalquantity,QOPTIMUM,isthereforesmallerthantheequilibriumquantity,QMARKET.QMARKETOptimumSocialcost(privatecostandexternalcost)ExternalCostQOPTIMUMEquilibrium9曼昆经济学原理第七版第10章外部性ExternalitiesandMarketInefficiencyNegativeexternalitiesOptimumquantityproducedMaximizetotalwelfareSmallerthanmarketequilibriumquantityGovernment–correctmarketfailureInternalizingtheexternalityAlteringincentivessothatpeopletakeaccountoftheexternaleffectsoftheiractions10曼昆经济学原理第七版第10章外部性ExternalitiesandMarketInefficiencyPositiveexternalitiesEducationBenefitofeducationisprivateExternalities:bettergovernment,lowercrimerates,higherproductivityandwagesSocialvalueisgreaterthanprivatevalueSocialvaluecurveAbovethedemandcurve11曼昆经济学原理第七版第10章外部性Figure3EducationandtheSocialOptimumPriceofEducationQuantityofEducation0Demand(privatevalue)Supply(privatecost)Inthepresenceofapositiveexternality,thesocialvalueofthegoodexceedstheprivatevalue.Theoptimalquantity,QOPTIMUM,isthereforelargerthantheequilibriumquantity,QMARKET.QMARKETEquilibriumSocialvalue(privatevalueandexternalbenefit)ExternalBenefitQOPTIMUMOptimum12曼昆经济学原理第七版第10章外部性ExternalitiesandMarketInefficiencyPositiveexternalitiesSociallyoptimalquantityisgreaterthanmarketequilibriumquantityGovernment–correctmarketfailureInternalizetheexternalitySubsidy13曼昆经济学原理第七版第10章外部性ExternalitiesandMarketInefficiencyNegativeexternalitiesMarketsproducealargerquantitythanissociallydesirableGovernment:taxPositiveexternalitiesMarketsproduceasmallerquantitythanissociallydesirableGovernment:subsidy14曼昆经济学原理第七版第10章外部性Technologyspillovers,industrialpolicy,andpatentprotectionTechnologyspillover=PositiveexternalityImpactofonefirm’sresearchandproductioneffortsonotherfirms’accesstotechnologicaladvanceGovernment:internalizetheexternalitySubsidy=valueofthetechnologyspillover15曼昆经济学原理第七版第10章外部性Technologyspillovers,industrialpolicy,andpatentprotectionIndustrialpolicyGovernmentinterventionintheeconomythataimstopromotetechnology-enhancingindustriesPatentlawProtecttherightsofinventorsbygivingthemexclusiveuseoftheirinventionsforaperiodoftime16曼昆经济学原理第七版第10章外部性PublicPoliciesTowardExternalitiesCommand-and-controlpoliciesRegulatebehaviordirectlyRegulationMarket-basedpoliciesProvideincentivessothatprivatedecisionmakerswillchoosetosolvetheproblemontheirownCorrectivetaxesandsubsidiesTradablepollutionpermits17曼昆经济学原理第七版第10章外部性PublicPoliciesTowardExternalitiesRegulationRegulatebehaviordirectly:makingcertainbehaviorseitherrequiredorforbiddenCannoteradicatepollutionEnvironmentalProtectionAgency(EPA)DevelopandenforceregulationsDictatesmaximumlevelofpollutionRequiresthatfirmsadoptaparticulartechnologytoreduceemissions18曼昆经济学原理第七版第10章外部性PublicPoliciesTowardExternalitiesCorrectivetaxesandsubsidiesCorrectivetaxes(Pigoviantaxes)InduceprivatedecisionmakerstotakeaccountofthesocialcoststhatarisefromanegativeexternalityPlacesapriceontherighttopolluteReducepollutionatalowercosttosocietyRaiserevenueforthegovernmentEnhanceeconomicefficiency19曼昆经济学原理第七版第10章外部性Whyisgasolinetaxedsoheavily?NegativeexternalitiesassociatedwithdrivingCongestion,accidents,pollution20曼昆经济学原理第七版第10章外部性Whyisgasolinetaxedsoheavily?Thegastax=correctivetaxDoesn’tcausedeadweightlossesMakestheeconomyworkbetterLesstrafficcongestionSaferroadsCleanerenvironment21曼昆经济学原理第七版第10章外部性Whyisgasolinetaxedsoheavily?Howhighshouldthetaxongasolinebe?MostEuropeancountriesHighergasolinetaxthanintheU.S.2007,JournalofEconomicLiteratureOptimalcorrectivetaxongasoline$2.28pergallonin2005dollars$2.70pergallonin2012dollarsActualtaxintheU.S.in2012:50centspergallon22曼昆经济学原理第七版第10章外部性Whyisgasolinetaxedsoheavily?TaxrevenuefromagasolinetaxUsedtolowertaxesthatdistortincentivesandcausedeadweightlossesSomegovernmentregulationsProductionoffuel-efficientcars–unnecessary23曼昆经济学原理第七版第10章外部性PublicPoliciesTowardExternalitiesTradablepollutionpermitsVoluntarytransferoftherighttopollutefromonefirmtoanotherNewscarceresource:pollutionpermitsMarkettotradepermitsFirm’swillingnesstopayDependonitscostofreducingpollution24曼昆经济学原理第七版第10章外部性PublicPoliciesTowardExternalitiesAdvantageoffreemarketforpollutionpermitsInitialallocationofpollutionpermitsdoesn'tmatterIffirmscanreducepollutionatalowcost:SellwhateverpermitstheygetIffirmscanreducepollutiononlyatahighcost:buywhateverpermitstheyneedEfficientfinalallocation25曼昆经济学原理第七版第10章外部性PublicPoliciesTowardExternalitiesReducingpollutionusingpollutionpermitsorcorrectivetaxesFirmspayfortheirpollutionCorrectivetaxes:paytothegovernmentPollutionpermits:paytobuypermitsInternalizetheexternalityofpollution26曼昆经济学原理第七版第10章外部性Figure4TheEquivalenceofCorrectiveTaxesandPollutionPermitsPriceofpollutionInpanel(a),theEPAsetsapriceonpollutionbylevyingacorrectivetax,andthedemandcurvedeterminesthequantityofpollution.Inpanel(b),theEPAlimitsthequantityofpollutionbylimitingthenumberofpollutionpermits,andthedemandcurvedeterminesthepriceofpollution.Thepriceandquantityofpollutionarethesameinthetwocases.0Quantityofpollution(a)CorrectiveTax(b)PollutionPermitsDemandforpollutionrightsQPCorrectivetax1.Acorrectivetaxsetsthepriceofpollution...2....which,togetherwiththedemandcurve,determinesthequantityofpollution.Priceofpollution0QuantityofpollutionDemandforpollutionrightsPQSupplyofpollutionpermits1.Pollutionpermitssetthequantityofpollution...2....which,togetherwiththedemandcurve,determinesthepriceofpollution.27曼昆经济学原理第七版第10章外部性PublicPoliciesTowardExternalitiesObjectionstotheeconomicanalysisofpollution“Wecannotgiveanyonetheoptionofpollutingforafee.”-bylateSenatorEdmundMuskiePeoplefacetrade-offsEliminatingallpollutionisimpossibleCleanwaterandcleanair–opportunitycostLowerstandardofliving28曼昆经济学原理第七版第10章外部性PublicPoliciesTowardExternalitiesCleanenvironmentisanormalgoodPositiveincomeelasticityRichcountriescanaffordacleanerenvironmentMorerigorousenvironmentalprotectionCleanairandcleanwater-lawofdemandThelowerthepriceofenvironmentalprotectionThemorethepublicwillwantit29曼昆经济学原理第七版第10章外部性PrivateSolutionstoExternalitiesThetypesofprivatesolutionsMoralcodesandsocialsanctionsCharitiesSelf-interestoftherelevantpartiesIntegratingdifferenttypesofbusinessesInterestedpartiescanenterintoacontract30曼昆经济学原理第七版第10章外部性PrivateSolutionstoExternalitiesTheCoasetheoremIfprivatepartiescanbargainwithoutcostovertheallocationofresourcesTheycansolvetheproblemofexternalitiesontheirownWhatevertheinitialdistributionofrightsInterestedpartiescanreachabargaininwhichEveryoneisbetteroffOutcomeisefficient31曼昆经济学原理第七版第10章外部性PrivateSolutionstoExternalities1.Dickhasthelegalrighttokeepabarkingdog.Dickgetsa$500benefitfromthedogJa