微觀經(jīng)濟(jì)學(xué)英文課件Ch

Externalities

外部性Chapter10MarketEfficiency-MarketFailure

市場(chǎng)效率和市場(chǎng)失靈Recallthat:AdamSmith’s“invisiblehand”ofthemarketplaceleadsself-interestedbuyersandsellersinamarkettomaximizethetotalbenefitthatsocietycanderivefromamarket.市場(chǎng)中看不見的手會(huì)引導(dǎo)自利的買賣雙方的行為，使得社會(huì)總福利最大化。Butmarketfailurescanstillhappen.但是市場(chǎng)可能會(huì)失靈Marketfailureresultsfrommarketpowerandexternality市場(chǎng)壟斷和外部性會(huì)導(dǎo)致市場(chǎng)失靈MarketFailures:Externalities

市場(chǎng)失靈：外部性Whenamarketoutcomeaffectspartiesotherthanthebuyersandsellersinthemarket,side-effectsarecreatedcalledexternalities.當(dāng)市場(chǎng)結(jié)果影響了買賣雙方之外的人，這種副作用我們就稱為外部性。Externalitiescausemarketstobeinefficient,andthusfailtomaximizetotalsurplus.外部性會(huì)使得市場(chǎng)缺乏效率，因此不能最大化總剩余。whenapersonengagesinanactivitythatinfluencesthewell-beingofabystanderandyetneitherpaysnorreceivesanycompensationforthateffect,anexternalityarises.當(dāng)一個(gè)人從事某種活動(dòng)時(shí)，影響到了旁觀者的福利，并且沒有因此付出代價(jià)或收到補(bǔ)償，我們就說有外部性產(chǎn)生。Whentheimpactonthebystanderisadverse,theexternalityiscalledanegativeexternality.如果對(duì)旁觀者的影響是不利的（不合意的），這種外部性就稱為負(fù)的外部性。Whentheimpactonthebystanderisbeneficial,theexternalityiscalledapositiveexternality.如果這種外部性是有益的，則稱為正的外部性。MarketFailures:Externalities

市場(chǎng)失靈：外部性ExamplesofNegativeExternalities

負(fù)的外部性的例子AutomobileexhaustCigarettesmokingBarkingdogs(loudpets)LoudstereosinanapartmentbuildingStinkyToufuImmunizations（接種疫苗）Restoredhistoricbuildings保護(hù)歷史建筑Researchintonewtechnologies研究新技術(shù)ExamplesofPositiveExternalities

正的外部性的例子TheMarketforAluminum...QuantityofAluminum0PriceofAluminumQMARKETDemand(privatevalue)Supply(privatecost)EquilibriumTheMarketforAluminum

andWelfareEconomicsThequantityproducedandconsumedinthemarketequilibriumisefficientinthesensethatitmaximizesthesumofproducerandconsumersurplus.Ifthealuminumfactoriesemitpollution(anegativeexternality),thenthecosttosocietyofproducingaluminumislargerthanthecosttoaluminumproducers.Foreachunitofaluminumproduced,thesocialcostincludestheprivatecostsoftheproducersplusthecosttothosebystandersadverselyaffectedbythepollution.QMARKETPollutionandtheSocialOptimum...QuantityofAluminum0PriceofAluminumDemand(privatevalue)Supply(privatecost)SocialcostQoptimumCostofpollutionEquilibriumOptimumNegativeExternalitiesinProduction

生產(chǎn)中的負(fù)的外部性Theintersectionofthedemandcurveandthesocial-costcurvedeterminestheoptimaloutputlevel.需求曲線和社會(huì)成本曲線的交點(diǎn)決定了最優(yōu)的產(chǎn)出水平Thesociallyoptimaloutputlevelislessthanthemarketequilibriumquantity.社會(huì)最優(yōu)的產(chǎn)出水平比市場(chǎng)均衡產(chǎn)量要小。AchievingtheSocially

OptimalOutputInternalizinganexternalityinvolvesalteringincentivessothatpeopletakeintoaccounttheexternaleffectsoftheiractions.將外部性內(nèi)部化改變了激勵(lì)，這樣人們決策時(shí)會(huì)考慮他們行為的外部作用。Thegovernmentcaninternalizeanexternalitybyimposingataxontheproducertoreducetheequilibriumquantitytothesociallydesirablequantity.政府可以通過對(duì)生產(chǎn)者征稅來內(nèi)部化外部性，將均衡產(chǎn)量降低到社會(huì)合意產(chǎn)量。PositiveExternalitiesinProduction

生產(chǎn)中的正的外部性Whenanexternalitybenefitsthebystanders,apositiveexternalityexists.Thesocialcostsofproductionarelessthantheprivatecosttoproducersandconsumers.生產(chǎn)的社會(huì)成本比生產(chǎn)者和消費(fèi)者的私人成本更低。Atechnologyspilloverisatypeofpositiveexternalitythatexistswhenafirm’sinnovationordesignnotonlybenefitsthefirm,butenterssociety’spooloftechnologicalknowledgeandbenefitssocietyasawhole.QuantityofRobots0PriceofRobotQOPTIMUMDemand(privatevalue)Supply(privatecost)SocialcostQMARKETValueoftechnologyspilloverEquilibriumOptimumPositiveExternalitiesinProductionTheintersectionofthedemandcurveandthesocial-costcurvedeterminestheoptimaloutputlevel.Theoptimaloutputlevelismorethantheequilibriumquantity.Themarketproducesasmallerquantitythanissociallydesirable.市場(chǎng)生產(chǎn)量小于社會(huì)合意的產(chǎn)量。Thesocialcostsofproductionarelessthantheprivatecosttoproducersandconsumers.PositiveExternalitiesinProductionInternalizingExternalities:SubsidiesGovernmentmanytimesusessubsidiesastheprimarymethodforattemptingtointernalizepositiveexternalities.政府通常使用補(bǔ)貼來將正的外部性內(nèi)部化。TechnologyPolicy

技術(shù)政策Governmentinterventionintheeconomythataimstopromotetechnology-enhancingindustriesiscalledtechnologypolicy.著眼于推動(dòng)技術(shù)進(jìn)步的政府對(duì)經(jīng)濟(jì)的干預(yù)政策成為技術(shù)政策。Patentlawsareaformoftechnologypolicythatgivetheindividual(orfirm)withpatentprotectionapropertyrightoveritsinvention.專利法是技術(shù)政策的一種，它對(duì)私人發(fā)明產(chǎn)權(quán)進(jìn)行專利保護(hù)。Thepatentisthensaidtointernalizetheexternality.據(jù)說專利可以內(nèi)部化外部性。InternalizingProductionExternalities

內(nèi)部化生產(chǎn)外部性Taxesaretheprimarytoolsusedtointernalizenegativeexternalities.稅收是內(nèi)部化負(fù)的外部性時(shí)的首選工具。Subsidiesaretheprimarytoolsusedtointernalizepositiveexternalities.補(bǔ)貼是內(nèi)部化正的外部性時(shí)的首選工具。QuantityofEducation0PriceofEducationQMARKETDemand(privatevalue)SocialvalueQOPTIMUM(b)PositiveConsumptionExternalitySupply(privatecost)QuantityofAlcohol0PriceofAlcoholQMARKETDemand(privatevalue)Supply(privatecost)SocialvalueQOPTIMUM(a)NegativeConsumptionExternalityConsumptionExternalities

消費(fèi)外部性ConsumptionExternalities

andMarketInefficiencyNegativeexternalitiesinproductionorconsumptionleadmarketstoproducealargerquantitythanissociallydesirable.生產(chǎn)和消費(fèi)中的負(fù)的外部性使得市場(chǎng)生產(chǎn)的數(shù)量比社會(huì)合意的數(shù)量要多。Positiveexternalitiesinproductionorconsumptionleadmarketstoproducealargerquantitythanissociallydesirable.生產(chǎn)和消費(fèi)中的正的外部性使得市場(chǎng)生產(chǎn)的數(shù)量比社會(huì)合意的數(shù)量要少。PrivateSolutionstoExternalities

外部性的私人解決方法Governmentactionisnotalwaysneededtosolvetheproblemofexternalities.解決外部性問題時(shí)并不總是需要政府。TypesofprivatesolutionsMoralcodesandsocialsanctions道德準(zhǔn)則和社會(huì)制裁Charitableorganizations慈善組織Integratingdifferenttypesofbusinesses整合不同的業(yè)務(wù)Contractingbetweenparties訂立合同TheCoaseTheorem

科斯定理TheCoaseTheoremstatesthatifprivatepartiescanbargainwithoutcostovertheallocationofresources,thentheprivatemarketwillalwayssolvetheproblemofexternalitiesonitsownandallocateresourcesefficiently.科斯定理表明，如果私人能夠就資源分配進(jìn)行沒有成本的談判，則私人市場(chǎng)自身就能解決外部性問題，并且有效地配置資源。TheCoaseTheoremTheCoaseTheoremsaysthatprivateeconomicactorscansolvetheproblemofexternalitiesamongthemselves.Whatevertheinitialdistributionofrights,theinterestedpartiescanalwaysreachabargaininwhicheveryoneisbetteroffandtheoutcomeisefficient.CoaseTheorem:MoreExampleAandBareroommate,AlikerockmusicandBpreferquiet.SupposeA’swillingnesstopayformusicis$50whileB’swillingnesstopayforquietis$40.Thinkabouttheinstitutionalarrangementasfollows:I.AhastherighttoplaymusicII.BhastherighttorequirequietWhatwillhappenifA’svalueformusicis$40whileB’svalueforquietis$50?SomeImportantConcept:PropertyrightsCoasianBargainingTransactionCostCoaseTheoremistheguidelineforustofigureouttherightreasonformarketinefficiencies.Wrongreasons:Externalityitself,unjustablepropertyrights,wrongdistributionofpropertyrightsRightreasons:ambiguousinitialpropertyrights,bargainingfailure(transactioncosttoohigh),restrictionsontransferofpropertyrights.Anotherexample:宿舍熄燈安排EquityEfficiency:transactioncost,credibilityofadmittance(difficulttoenforceacontract),multiperson,information.WhyPrivateSolutions

DoNotAlwaysWorkTransactioncostsarethecoststhatpartiesincurintheprocessofagreeingtoandfollowingthroughonabargain.交易成本是各方在談判和達(dá)成協(xié)議的過程中產(chǎn)生的費(fèi)用。Sometimestheprivatesolutionapproachfailsbecausetransactioncostscanbesohighthatprivateagreementisnotpossible.有時(shí)因?yàn)榻灰壮杀咎咚饺瞬荒苓_(dá)成協(xié)議，則私人的解決方法失靈。PublicPolicytowardExternalitoiesWhenexternalitiesaresignificantandprivatesolutionsarenotfound,governmentmayattempttosolvetheproblemthrough...如果外部性很顯著而且私人方法不起作用，政府會(huì)通過下列手段來試圖解決問題：command-and-controlpolicies.指令性政策market-basedpolicies.基于市場(chǎng)的政策Command-and-ControlPolicies

指令性政策Usuallytaketheformofregulations:Forbidcertainbehaviors.Requirecertainbehaviors.Examples:Requirementsthatallstudentsbeimmunized.StipulationsonpollutionemissionlevelssetbytheEnvironmentalProtectionAgency(EPA).Market-basedPoliciesGovernmentusestaxesandsubsidiestoalignprivateincentiveswithsocialefficiency.Pigoviantaxesaretaxesenactedtocorrecttheeffectsofanegativeexternality.ExamplesofRegulation

versusPigoviantaxIftheEPAdecidesitwantstoreducetheamountofpollutioncomingfromaspecificplant.TheEPAcould…tellthefirmtoreduceitspollutionbyaspecificamount(i.e.regulation).levyataxofagivenamountforeachunitofpollutionthefirmemits(i.e.Pigoviantax).Market-basedPoliciesTradablepollutionpermitsallowthevoluntarytransferoftherighttopollutefromonefirmtoanother.Amarketforthesepermitswilleventuallydevelop.Afirmthatcanreducepollutionatalowcostmayprefertosellitspermittoafirmthatcanreducepollutiononlyatahighcost.TheEquivalenceofPigovianTaxesandPollutionPermits...QuantityofPollution0PriceofPollutionPQDemandforpollutionrightsPigoviantax(a)PigovianTax2....which,togetherwiththedemandcurve,determinesthequantityofpollution.1.APigoviantaxsetsthepriceofpoll