经济学（微观）（英文版原书第7版）课件 第15章　垄断和反垄断政策

EconomicsSeventhEditionChapter15MonopolyandAntitrustPolicyCopyright©2019,2017,2015PearsonEducation,Inc.AllRightsReserved.ChapterOutline15.1

IsAnyFirmEverReallyaMonopoly?15.2

WhereDoMonopoliesComeFrom?15.3

HowDoesaMonopolyChoosePriceandOutput?15.4

DoesMonopolyReduceEconomicEfficiency?15.5

GovernmentPolicyTowardMonopoly15.1IsAnyFirmEverReallyaMonopoly?Definemonopoly.Monopolyisamarketstructureconsistingofafirmthatistheonlysellerofagoodorservicethatdoesnothaveaclosesubstitute.Monopolyexistsattheoppositeendofthecompetitionspectrumtoperfectcompetition.Westudymonopoliesfortworeasons:Somefirmstrulyaremonopolists,soitisimportanttounderstandhowtheybehave.Firmsmightcolludeinordertoactlikeamonopolist;knowinghowmonopoliesacthelpsustoidentifythesefirms.DoMonopoliesReallyExist?Supposeyouliveinasmalltownwithonlyonepizzeria.Isthatpizzeriaamonopoly?IthascompetitionfromotherfastfoodrestaurantsIthascompetitionfromgrocerystoresthatprovidepizzasforyoutocookathomeIfyouconsiderthesealternativestobeclosesubstitutesforpizzeriapizza,thenthepizzarestaurantisnotamonopoly.Ifyoudonotconsiderthesealternativestobeclosesubstitutesforpizzeriapizza,thenthepizzarestaurantisamonopoly.Regardless,thepizzeria’suniquepositionmayafforditsomemonopolypowertoraisepricesandobtaineconomicprofit.ApplytheConcept:IstheNCAAaMonopoly?TheNCAAgovernscollegeathleticsatmorethan1,200institutions.HarvardeconomistRobertBarroclaimstheNCAAiseffectivelyamonopoly,usingitsmonopolypowertodecrease/eliminatewhatstudent-athletesreceivefortheirathleticefforts.VariousantitrustlawsuitshavebeenbroughtagainsttheNCAAovertime,someresultingingreatertelevisionaccessandevenstipendsforsomeathletes.15.2WhereDoMonopoliesComeFrom?Explainthefourmainreasonsmonopoliesarise.Forafirmtoexistasamonopoly,theremustbebarrierstoentrypreventingotherfirmscominginandcompetingwithit.Thefourmainreasonsforthesebarrierstoentryare:GovernmentrestrictionsonentryControlofakeyresourceNetworkexternalitiesNaturalmonopolyThenextfewslideswillexaminetheseindetail.1.GovernmentRestrictionsonEntry(1of2)IntheU.S.,governmentsblockentryintwomainways:Patents,copyrights,andtrademarksNewlydevelopedproductslikedrugsarefrequentlygrantedpatents,theexclusiverighttoproduceaproductforaperiodof20yearsfromthedatethepatentisfiledwiththegovernment.Similarly,copyrightsprovidetheexclusiverighttoproduceandsellcreativeworkslikebooksandfilms,andtrademarksofferprotectionforbrandnames,symbols,andsomecharacteristics.Theseintellectualpropertyprotectionsencourageinnovationandcreativity,sincewithoutthem,firmswouldhaveahardertimecoveringhighfixedcosts.1.GovernmentRestrictionsonEntry(2of2)IntheU.S.,governmentsblockentryintwomainways:PublicfranchisesAgovernmentdesignationthatafirmistheonlylegalproviderofagoodorserviceisknownasapublicfranchise.Thesemightexist,forexample,inelectricityorwatermarkets.Sometimes(morecommonlyinEuropethantheU.S.)governmentsevenoperatethesefirmsasapublicenterprise.AU.S.exampleofthisistheU.S.PostalService.ApplytheConcept:DoesHasbroHaveaMonopolyonMonopoly?HasbroisthemultinationalAmericancompanythatownsMonopoly—originallytrademarkedbyParkerBrothersin1935.Unlikepatentsandcopyrights,trademarksneverexpire.Withoutthetrademark,otherfirmscouldmarketsimilargameswiththesametitle,dilutingHasbro’sprofits.Inthe1970s,aCalifornianeconomicsprofessorstartedsellingagamecalledAnti-Monopoly.Hasbrosuedtheprofessor;eventuallythetwopartiesreachedalicensingagreement.2.ControlofaKeyResourceFormanyyears,theAluminumCompanyofAmerica(Alcoa)eitherownedorhadlong-termcontractsforalmostalltheworld’ssupplyofbauxite,themineralfromwhichweobtainaluminum.Suchcontroloverakeyresourceservedasasubstantialbarriertoentryforadditionalfirms.TheNationalFootballLeague(NFL)actsasamonopolyinthismannertoo:itensuresthatthemajorityoftheworld’sbestfootballplayersareundercontracttotheNFLandunabletobeusedforanotherpotentialleague.ApplytheConcept:AreDiamondProfitsForever?ThemostfamousmonopolybasedoncontrolofarawmaterialistheDeBeersdiamondmonopoly.DeBeerssoughttocontrolasmuchofthesupplyofdiamondsaspossible,soitcouldkeeppriceshigh.Butby2000,newcompetitorshaderodedDeBeers’controloftheworld’sdiamondproductionto40percent.Tomaintainitsmonopolypower,DeBeersintroducedthe“Forevermark”brandforitsdiamonds.Doyouthinkthismarketingstrategywillwork?3.NetworkExternalitiesEconomistsrefertonetworkexternalitiesasaproductcharacteristicwherebytheusefulnessofaproductincreaseswiththenumberofconsumerswhouseit.Examples: Auctionsites(likeeBay)Computeroperatingsystems(likeWindows)Socialnetworkingsites(likeFacebook)Thesenetworkexternalitiescansetoffavirtuouscycleforafirm,allowingthevalueofitsproducttocontinuetoincrease,alongwiththepriceitcancharge.Butconsumersmaybelockedintoaninferiorproduct.4.NaturalMonopolyAnaturalmonopoly

occurswheneconomiesofscalearesolargethatonefirmcansupplytheentiremarketataloweraveragetotalcostthancantwoormorefirms.Naturalmonopoliesaremostlikelywhenfixedcostsarehigh.Example:Afirmproducingelectricitymustmakeasubstantialinvestmentinproductionanddistributioninfrastructure;themarginalcostofproducinganotherhourofelectricityislow.Figure15.1AverageTotalCostCurveforaNaturalMonopolyInthemarketforelectricitydelivery,asinglefirm(pointA)candeliverelectricityatalowercostthancantwofirms(pointB).15.3HowDoesaMonopolyChoosePriceandOutput?Explainhowamonopolychoosespriceandoutput.Inourstudyofoligopoly,weabandonedtheideaofmarginalcostandmarginalrevenue,becausethestrategicinteractionbetweenfirmsoverrodetheseconcepts.Butmonopolistshavenocompetitorsandhencenoconcernaboutstrategicinteractions.Theyseektomaximizeprofitbychoosingaquantitytoproduce,justlikeperfectandmonopolisticcompetitors.Infact,monopolistsactverymuchlikemonopolisticcompetitors:theyfaceadownwardslopingdemandcurve.Thedifferenceisthatbarrierstoentrywillpreventotherfirmsfromcompetingawaytheireconomicprofit.Figure15.2CalculatingaMonopoly’sRevenue(1of2)TimeWarnerCableisamonopolistinalocalmarketforcabletelevisionservices.Thefirsttwocolumnsofthetableshowthemarketdemandcurve,whichisalsoComcast’sdemandcurve.Total,average,andmarginalrevenueareallcalculatedintheusualmanner.SubscribersperMonth(Q)Price(P)TotalRevenue(TR=P×Q)AverageRevenue(AR=TR/Q)MarginalRevenue(MR=∆TR/∆Q)0$60$0––15757$57$5725410854513511535145448192483954522545336422524227739273392183628836159332973391030300303Figure15.2CalculatingaMonopoly’sRevenue(2of2)Asthemonopolistdecreasespricetoexpandoutput,twoeffectsoccur:Revenueincreasesfromsellinganextraunitofoutput.Revenuedecreases,becausethepricereductionissharedwithexistingcustomers.Somarginalrevenueisalwaysbelowdemandforamonopolist.Figure15.3Profit-MaximizingPriceandOutputforaMonopoly(1of2)Themonopolistmaximizesprofitbyproducingthequantitywheretheadditionalrevenuefromthelastunit(marginalrevenue)justequalstheadditionalcostincurredfromitsproduction(marginalcost).MC=MRdeterminesquantityforamonopolist.Figure15.3Profit-MaximizingPriceandOutputforaMonopoly(2of2)Atthisquantity,Thedemandcurvedeterminesprice,andTheaveragetotalcost(ATC)curvedeterminesaveragecost.Profitisthedifferencebetweenthese(P−ATC),timesquantity(Q).Long-RunProfitsforaMonopolySincetherearebarrierstoentry,additionalfirmscannotenterthemarket.Sothereisnodistinctionbetweentheshortrunandlongrunforamonopoly.Thenunlikeformonopolisticcompetition,weexpectmonopoliststocontinuetoearnprofitsinthelongrun.15.4DoesMonopolyReduceEconomicEfficiency?Useagraphtoillustratehowamonopolyaffectseconomicefficiency.Supposethatamarketcouldbecharacterizedbyeitherperfectcompetitionormonopoly.Whichwouldbebetter?Thoughtexperiment:supposethemarketforsmartphonesisperfectlycompetitive,thenonefirmbuysupallofthesmartphonesinthecountry.Whatwouldhappento:Priceofsmartphones?Quantityofsmartphonestraded?Thenetbenefitofconsumers(i.e.consumersurplus)?Thenetbenefitofproducers(i.e.producersurplus)?Thenetbenefitofallofsociety(i.e.economicsurplus)?Figure15.4WhatHappensifaPerfectlyCompetitiveIndustryBecomesaMonopoly?(1of2)Themarketforsmartphonesisinitiallyperfectlycompetitive.PriceisPC,quantitytradedisQC.Nowthemarketissuppliedbyasinglefirm.Sincethesinglefirmismadeupofallofthesmallerfirms,themarginalcostcurveforthisnewfirmisidenticaltotheoldsupplycurve.Figure15.4WhatHappensifaPerfectlyCompetitiveIndustryBecomesaMonopoly?(2of2)Butthenewfirmmaximizesmarketprofit,producingthequantitywheremarginalcostequalsmarginalrevenue(MC=MR).Thisquantity(QM)islowerthanthecompetitivequantity(QC)……andthefirmchargesthecorrespondingpriceonthedemandcurve,PM.Thispriceishigherthanthecompetitiveprice,PC.MeasuringtheEfficiencyLossesfromMonopolyFewersmartphoneswillbetradedatahigherprice.Consumersurpluswillfall(withthehigherprice).Producersurplusmustrise,otherwisethefirmwouldhavechosentheperfectlycompetitivepriceandquantity.Couldtheincreaseinproducersurplusoffsetthedecreaseinconsumersurplus?No!Perfectlycompetitivemarketsmaximizedtheeconomic(total)surplusinamarket;iffewertradestakeplace,theeconomicsurplusmustfall.Figure15.5TheInefficiencyofMonopoly(1of2)Withthehighermonopolyprice,consumersurplusdecreasesbytheareasA+B.ProducersurplusfallsbyC,butrisesbyA;anoverallincrease.AreaAsimplyissimplyatransferofsurplus:neitherinherentlygoodnorbad.ButareasBandCarelostsurpluses:deadweightloss.Figure15.5TheInefficiencyofMonopoly(2of2)Themarginalcostofthenextunit(MCM)islessthanthepriceconsumersarewillingtopay(PM).Ifthemarketwereperfectlycompetitive,thisunitwouldbesupplied,andeconomicsurpluswouldincrease.Butthiswoulddecreasethemonopolist’sprofit,soitwillnotbeproduced.HowLargeAretheEfficiencyLosses?Therearerelativelyfewmonopolies,sothelossofeconomicefficiencyduetomonopoliesmustberelativelysmall.Butmanyfirmshavemarketpower:theabilityofafirmtochargeapricegreaterthanmarginalcost.Infact,theonlyfirmsthatdonothavemarketpowerareperfectlycompetitivefirms,andperfectcompetitionisrare.Economistsestimatethatoverall,thelossofefficiencyintheUnitedStatesduetomarketpowerisprobablylessthan1percentoftotalU.S.production—lessthan$600perpersonannually.Whysolow?Mostfirmsfacearelativelylargedegreeofcompetition,resultinginpricesmuchclosertomarginalcostthanwewouldseewithmonopolies.Sodeadweightlossduetomarketpowerisrelativelysmall.MarketPowerandTechnologicalChangeMarketpowermayproducesomebenefitforaneconomy:theprospectofmarketpower(andtheresultingeconomicprofits)drivesfirmstoinnovate,creatingnewproductsandservices.Thisdriveaffectsbothlargefirms—whoreinvestprofitsinthehopeofmakinglargerfutureprofits—andsmallfirms—whohopetoobtainprofitsforthemselves.TheAustrianeconomistJosephSchumpeterclaimedthatthisdrivewouldcreatea“galeofcreativedestruction”thatwouldeventuallybenefitconsumersmorethanincreasedpricecompetition.Thishelpstoexplaingovernmentalambivalenceregardinglargefirmswithmarketpower.15.5GovernmentPolicyTowardMonopolyExplainhowthegovernmentregulatesmonopoly.Becausemonopoliesreduceconsumersurplusandeconomicefficiency,governmentsregulatetheirbehavior.Manygovernmentstrytostopfirmscolludingandseektopreventmergersandacquisitionscreatinglargefirms,throughantitrustlaws.Collusion:Anagreementamongfirmstochargethesamepriceorotherwisenottocompete.Antitrustlaws:Lawsaimedateliminatingcollusionandpromotingcompetitionamongfirms.Table15.1ImportantU.S.AntitrustLawsInthe1870sand1880s,several“trusts”hadformed:boardsoftrusteesthatoversawtheoperationofseveralfirmsinanindustryandenforcedcollusiveagreements.Thefederalgovernmentrespondedwithantitrustlawstolimitanti-competitivebehavior.LawDateEnactedbyCongressPurposeShermanAct1890Prohibited“restraintoftrade,”includingpricefixingandcollusion.Alsooutlawedmonopolization.ClaytonAct1914Prohibitedfirmsfrombuyingstockincompetitorsandfromhavingdirectorsserveontheboardsofcompetingfirms.FederalTradeCommissionAct1914EstablishedtheFederalTradeCommission(FTC)tohelpadministerantitrustlaws.Robinson–PatmanAct1936Prohibitedfirmsfromchargingbuyersdifferentpricesiftheresultwouldreducecompetition.Cellar–KefauverAct1950Toughenedrestrictionsonmergersbyprohibitinganymergersthatwouldreducecompetition.ApplytheConcept:HaveGenericDrugFirmsBeenColludingtoRaisePrices?(1of2)Drugsforwhichthepatenthasexpiredarecalledgenericdrugs;theseconstituteabout88%ofallU.S.prescriptions.Intensecompetitioninthegenericdrugmarketcommonlyresultsinlowpricesforgenericdrugs.Butthismeansfirmshaveastrongincentivetobreakantitrustlawsandcolludetoraiseprices.ApplytheConcept:HaveGenericDrugFirmsBeenColludingtoRaisePrices?(2of2)Inearly2017,twoexecutivesatHeritagePharmaceuticalsInc.pleadedguiltytocolludingwithotherfirmstofixthepricesofanantibioticandadiabetesdrug.TheDepartmentofJusticeisinvestigatingotherfirmstodeterminehowwidespreadcollusionhasbecome.Figure15.6AMergerThatMakesConsumersBetterOff(1of2)Antitrustlawsalsocovermergers;particularlyhorizontalmergers:mergersbetweenfirmsinthesameindustry,asopposedtoverticalmergersbetweentwofirmsatdifferentstagesoftheproductionprocess.Suchmergersarelikelyenhancefirms’marketpower.Thegraphshowssuchamerger,increasingthepricefromthecompetitiveprice(PC)tothemonopolyprice(PM),andresultingindeadweightloss.Figure15.6AMergerThatMakesConsumersBetterOff(2of2)Firmsseekingtomergetypicallyarguethattheresultinglargerfirmwillhavelowercosts,andhencebeabletoproducemoreefficiently.Theneveniftheychargethe(new)monopolyprice,theresultisanimprovementforconsumers.However,costsmaynotdecreasebyasmuchasthefirmsclaim,resultinginconsumersbeingworseoff.EconomistswiththeFTCandDepartmentofJusticereviewpotentialmergersone-by-one.DOJandFTCMergerGuidelinesEconomistsandlawyersattheDepartmentofJusticeandtheFederalTradeCommissionhavedevelopedguidelinesforthemselvesandfirmstouseinevaluatingwhetherapotentialmergerisacceptable.Theseinclude:MarketdefinitionMeasureofconcentrationMergerstandardsWewillexamineeachoftheseonthefollowingslides.1.MarketDefinitionSupposeHersheyFoodssoughttomergewithMarsInc.Inwhatmarketdothesefirmscompete?Themarketforcandy?Themarketforsnacks?Themarketforallfood?Themorebroadlydefinedthemarket,thesmaller(andmoreharmless)themergerappears.Todeterminetheappropriatescopeofthemarket,thegovernmenttriestodeterminewhichgoodsareclosesubstitutesforthoseproducedbythefirms.The“appropriatemarket”isdefinedasthesmallestmarketcontainingthefirms’productsforwhichanoverallpricerisewithinthemarketwouldresultintotalmarketprofitsincreasing.(Ifprofitswoulddecrease,theremustbeadequatesubstitutesavailable;hencethemarketistoonarrowlydefined.)2.MeasureofConcentrationAmarketisconcentratedifarelativelysmallnumberoffirmshavealargeshareoftotalsalesinthemarket.Todetermineifamarketisconcentrated,thegovernmentusestheHerfindahl-HirschmanIndex(HHI)createdbysquaringthepercentagemarketsharesofeachfirmandaddinguptheresults.Someexamplesaregivenbelow:FirmmarketsharesFormulaHHI100%100210,00050%,50%502+5025,00030%,30%,20%,20%302+302+202+2022,60010%,10%,…,10%10×1021,000Table15.2FederalGovernmentStandardsforHorizontalMergersVa