曼昆经济学原理英文版文案加习题答案10章

182©2012CengageLearning.AllRightsReserved.Maynotbescanned,copiedorduplicated,orpostedtoapubliclyaccessiblewebsite,inwholeorinpart.Chapter10ExternalitiesWHAT’SNEWINTHESEVENTHEDITION:ThereisanewIntheNewsfeatureon“WhatShouldWeDoaboutClimateChange.”LEARNINGOBJECTIVES:Bytheendofthischapter,studentsshouldunderstand:whatanexternalityis.whyexternalitiescanmakemarketoutcomesinefficient.thevariousgovernmentpoliciesaimedatsolvingtheproblemofexternalities.howpeoplecansometimessolvetheproblemofexternalitiesontheirown.whyprivatesolutionstoexternalitiessometimesdonotwork.CONTEXTANDPURPOSE:Chapter10isthefirstchapterinthemicroeconomicsectionofthetext.Itisthefirstchapterinathree-chaptersequenceontheeconomicsofthepublicsector.Chapter10addressesexternalities—theuncompensatedimpactofoneperson’sactionsonthewell-beingofabystander.Chapter11willaddresspublicgoodsandcommonresources(goodsthatwillbedefinedinChapter11)andChapter12willaddressthetaxsystem.InChapter10,differentsourcesofexternalitiesandavarietyofpotentialcuresforexternalitiesareaddressed.Marketsmaximizetotalsurplustobuyersandsellersinamarket.However,ifamarketgeneratesanexternality(acostorbenefittosomeoneexternaltothemarket)themarketequilibriummaynotmaximizethetotalbenefittosociety.Thus,inChapter10wewillseethatwhilemarketsareusuallyagoodwaytoorganizeeconomicactivity,governmentscansometimesimprovemarketoutcomes.EXTERNALITIES100Chapter10/Externalities❖183©2012CengageLearning.AllRightsReserved.Maynotbescanned,copiedorduplicated,orpostedtoapubliclyaccessiblewebsite,inwholeorinpart.KEYPOINTS:Whenatransactionbetweenabuyerandsellerdirectlyaffectsathirdparty,theeffectiscalledanexternality.Ifanactivityyieldsnegativeexternalities,suchaspollution,thesociallyoptimalquantityinamarketislessthantheequilibriumquantity.Ifanactivityyieldspositiveexternalities,suchastechnologyspillovers,thesociallyoptimalquantityisgreaterthantheequilibriumquantity.Governmentspursuevariouspoliciestoremedytheinefficienciescausedbyexternalities.Sometimesthegovernmentpreventssociallyinefficientactivitybyregulatingbehavior.Othertimesitinternalizesanexternalityusingcorrectivetaxes.Anotherpublicpolicyistoissuepermits.Forexample,thegovernmentcouldprotecttheenvironmentbyissuingalimitednumberofpollutionpermits.Theresultofthispolicyislargelythesameasimposingcorrectivetaxesonpolluters.Thoseaffectedbyexternalitiescansometimessolvetheproblemprivately.Forinstance,whenonebusinessimposesanexternalityonanotherbusiness,thetwobusinessescaninternalizetheexternalitybymerging.Alternatively,theinterestedpartiescansolvetheproblembynegotiatingacontract.AccordingtotheCoasetheorem,ifpeoplecanbargainwithoutcost,thentheycanalwaysreachanagreementinwhichresourcesareallocatedefficiently.Inmanycases,however,reachingabargainamongthemanyinterestedpartiesisdifficult,sotheCoasetheoremdoesnotapply.CHAPTEROUTLINE:I.Definitionofexternality:theuncompensatedimpactofoneperson’sactionsonthewell-beingofabystander.A.Iftheimpactonthebystanderisadverse,wesaythatthereisanegativeexternality.B.Iftheimpactonthebystanderisbeneficial,wesaythatthereisapositiveexternality.C.Ineithersituation,decisionmakersfailtotakeaccountoftheexternaleffectsoftheirbehavior.II.ExternalitiesandMarketInefficiencyA.WelfareEconomics:ARecap1.Thedemandcurveforagoodreflectsthevalueofthatgoodtoconsumers,measuredbythepricethatthemarginalbuyeriswillingtopay.2.Thesupplycurveforagoodreflectsthecostofproducingthatgood.3.Inafreemarket,thepriceofagoodbringssupplyanddemandintobalanceinawaythatmaximizestotalsurplus(thedifferencebetweentheconsumers’valuationofthegoodandthesellers’costofproducingit).Figure1Givestudentsseveralexamplesofbothpositiveandnegativeexternalities.Usecurrenthealthdebatesorpoliticaltopicstomaintaininterest.184❖Chapter10/Externalities©2012CengageLearning.AllRightsReserved.Maynotbescanned,copiedorduplicated,orpostedtoapubliclyaccessiblewebsite,inwholeorinpart.B.NegativeExternalities1.Example:Analuminumfirmemitspollutionduringproduction.2.Socialcostisequaltotheprivatecosttothefirmofproducingthealuminumplustheexternalcoststothosebystandersaffectedbythepollution.Thus,socialcostexceedstheprivatecostpaidbyproducers.3.Theoptimalamountofaluminuminthemarketwilloccurwheretotalsurplusismaximized.a.Totalsurplusisequaltothevalueofaluminumtoconsumersminusthecost(socialcost)ofproducingit.b.Thiswilloccurwherethesocial-costcurveintersectswithdemandcurve.Atthispoint,producingonemoreunitwouldlowertotalsurplusbecausethevaluetoconsumersislessthanthecosttoproduceit.4.Becausethesupplycurvedoesnotreflectthetruecostofproducingaluminum,themarketwillproducemorealuminumthanisoptimal.5.Thisnegativeexternalitycouldbeinternalizedbyataxonproducersforeachunitofaluminumsold.Figure2Makesurethatstudentsunderstandhowthispollutionbythefirmimposescostsonthirdparties.Pointoutthatthefirmislikelyemittingpollutionbecausethisisthecheapestmethodofproduction.Stressthatthefirmisusingaresourceinproductionthatitisnotpayingfor.ALTERNATIVECLASSROOMEXAMPLE:Acoal-firedpowerplantemitspollutionduringproduction.Chapte