國際經(jīng)濟(jì)學(xué)課件06

Chapter6EconomiesofScale,ImperfectCompetition,andInternationalTradePreviewTypesofeconomiesofscaleTypesofimperfectcompetitionOligopolyandmonopolyMonopolisticcompetitionMonopolisticcompetitionandtradeInter-industrytradeandintra-industrytradeDumpingExternaleconomiesofscaleandtrade2Copyright?2009PearsonAddison-Wesley.Allrightsreserved.IntroductionWhendefiningcomparativeadvantage,theRicardianandHeckscher-Ohlinmodelsassumethatproductionprocesseshaveconstantreturnstoscale:Whenfactorsofproductionchangeatacertainrate,outputincreasesatthesamerate.Forexample,ifallfactorsofproductionaredoubledthenoutputwillalsodouble.Butafirmorindustrymayhaveincreasingreturnstoscaleoreconomiesofscale:Whenfactorsofproductionchangeatacertainrate,outputincreasesatafasterrate.Alargerscaleismoreefficient:thecostperunitofoutputfallsasafirmorindustryincreasesoutput.3Copyright?2009PearsonAddison-Wesley.Allrightsreserved.Introduction(cont.)TheRicardianandHeckscher-Ohlinmodelsalsorelyoncompetitiontopredictthatallincomefromproductionispaidtoownersoffactorsofproduction:no“excess”ormonopolyprofitsexist.Butwheneconomiesofscaleexist,largefirmsmaybemoreefficientthansmallfirms,andtheindustrymayconsistofamonopolyorafewlargefirms.Productionmaybeimperfectlycompetitiveinthesensethatexcessormonopolyprofitsarecapturedbylargefirms.4Copyright?2009PearsonAddison-Wesley.Allrightsreserved.TypesofEconomiesofScaleEconomiesofscalecouldmeaneitherthatlargerfirmsoralargerindustryismoreefficient.Externaleconomiesofscaleoccurwhencostperunitofoutputdependsonthesizeoftheindustry.Internaleconomiesofscaleoccurwhenthecostperunitofoutputdependsonthesizeofafirm.5Copyright?2009PearsonAddison-Wesley.Allrightsreserved.TypesofEconomiesofScale(cont.)Externaleconomiesofscalemayresultifalargerindustryallowsformoreefficientprovisionofservicesorequipmenttofirmsintheindustry.Manysmallfirmsthatarecompetitivemaycomprisealargeindustryandbenefitwhenservicesorequipmentcanbeefficientlyprovidedtoallfirmsintheindustry.Internaleconomiesofscaleresultwhenlargefirmshaveacostadvantageoversmallfirms,causingtheindustryto

become

uncompetitive.6Copyright?2009PearsonAddison-Wesley.Allrightsreserved.AReviewofMonopolyAmonopolyisanindustrywithonlyonefirm.Anoligopolyisanindustrywithonlyafewfirms.Intheseindustries,themarginalrevenuegeneratedfromsellingmoreproductsislessthantheuniformpricechargedforeachproduct.Tosellmore,afirmmustplantolowerthepriceofadditionalunitsaswellasofexistingunits,whenitcannotpricediscriminate.Themarginalrevenuefunctionthereforeliesbelowthedemandfunction(whichdeterminesthepricethatcustomersarewillingtopay).7Copyright?2009PearsonAddison-Wesley.Allrightsreserved.Fig.6-1:MonopolisticPricingandProductionDecisions8Copyright?2009PearsonAddison-Wesley.Allrightsreserved.AReviewofMonopoly(cont.)Averagecostisthecostofproduction(C)dividedbythetotalquantityofproduction(Q).AC=C/QMarginalcostisthecostofproducinganadditionalunitofoutput.9Copyright?2009PearsonAddison-Wesley.Allrightsreserved.AReviewofMonopoly(cont.)SupposethatcostsarerepresentedbyC=F+cQ,whereFrepresentsfixedcosts,thoseindependentofthelevelofoutput.crepresentsaconstantmarginalcost:aconstantcostofproducinganadditionalquantityofproductionQ.AC=F/Q+cAlargerfirmismoreefficientbecauseaveragecostdecreasesasoutputQincreases:internaleconomiesofscale.10Copyright?2009PearsonAddison-Wesley.Allrightsreserved.Fig.6-2:AverageVersusMarginalCost11Copyright?2009PearsonAddison-Wesley.Allrightsreserved.MonopolisticCompetitionMonopolisticcompetitionisamodelofanimperfectlycompetitiveindustrywhichassumesthatEachfirmcandifferentiateitsproductfromtheproductofcompetitors.Eachfirmignorestheimpactthatchangesinitspricewillhaveonthepricesthatcompetitorsset:eventhougheachfirmfacescompetitionitbehavesasifitwereamonopolist.12Copyright?2009PearsonAddison-Wesley.Allrightsreserved.MonopolisticCompetition(cont.)Afirminamonopolisticallycompetitiveindustryisexpected:tosellmoreastotalsalesintheindustryincreaseandaspriceschargedbyrivalsincrease.toselllessasthenumberoffirmsintheindustrydecreasesandasitspriceincreases.Theseconceptsarerepresentedbythefunction:13Copyright?2009PearsonAddison-Wesley.Allrightsreserved.MonopolisticCompetition(cont.)Q=S[1/n–b(P–P)]Qisanindividualfirm’ssalesSisthetotalsalesoftheindustrynisthenumberoffirmsintheindustrybisaconstanttermrepresentingtheresponsivenessofafirm’ssalestoitspricePisthepricechargedbythefirmitselfPistheaveragepricechargedbyitscompetitors14Copyright?2009PearsonAddison-Wesley.Allrightsreserved.MonopolisticCompetition(cont.)Tomakethemodeleasiertounderstand,weassumethatallfirmsfacethesamedemandfunctionsandhavethesamecostfunctions:Thusinequilibrium,allfirmsshouldchargethesameprice:P=PInequilibrium,Q=S/n+0AC=C/Q=F/Q+c=F(n/S)+c15Copyright?2009PearsonAddison-Wesley.Allrightsreserved.MonopolisticCompetition(cont.)AC=F(n/S)+cAsthenumberoffirmsnintheindustryincreases,theaveragecostincreasesforeachfirmbecauseeachproducesless.AstotalsalesSoftheindustryincrease,theaveragecostdecreasesforeachfirmbecauseeachproducesmore.16Copyright?2009PearsonAddison-Wesley.Allrightsreserved.Fig.6-3:EquilibriuminaMonopolisticallyCompetitiveMarket17Copyright?2009PearsonAddison-Wesley.Allrightsreserved.MonopolisticCompetition(cont.)Ifmonopolisticfirmshavelineardemandfunctions,thentherelationshipbetweenpriceandquantitymayberepresentedas:Q=A–BxPwhereAandBareconstantsandmarginalrevenuemayberepresentedasMR=P–Q/BWhenfirmsmaximizeprofits,theyshouldproduceuntilmarginalrevenueisnogreaterthanornolessthanmarginalcost:MR=P–Q/B=c18Copyright?2009PearsonAddison-Wesley.Allrightsreserved.MonopolisticCompetition(cont.)Q=S[1/n–b(P–P)]Q=S/n–Sb(P–P)Q=S/n+SbP–SbP

Q=A–BxPLetA

≡

S/n+SbP

andB≡

Sb19Copyright?2009PearsonAddison-Wesley.Allrightsreserved.MonopolisticCompetition(cont.)MR=P–Q/B=cMR=P–Q/Sb=cP=c+Q/SbP=c+(S/n)/SbP=c+1/(nxb)Asthenumberoffirmsnintheindustryincreases,thepricethateachfirmchargesdecreasesbecauseofincreasedcompetition.20Copyright?2009PearsonAddison-Wesley.Allrightsreserved.MonopolisticCompetition(cont.)Atsomenumberoffirms,thepricethatfirmscharge(whichdecreasesinn)matchestheaveragecostthatfirmspay(whichincreasesinn).Whentheindustryhasthisnumberoffirms,eachfirmwillearnrevenuethatexactlyoffsetsallcosts(includingopportunitycosts):pricewillmatchaveragecost.Thisnumberistheequilibriumnumberoffirmsintheindustrybecausefirmshavenoincentiveortendencytoenterorexittheindustry.21Copyright?2009PearsonAddison-Wesley.Allrightsreserved.MonopolisticCompetition(cont.)Ifthenumberoffirmsisgreaterthanorlessthantheequilibriumnumber,thenfirmshaveanincentivetoexitorentertheindustry.Firmshaveanincentivetoentertheindustrywhenrevenuesexceedallcosts(price>averagecost).Firmshaveanincentivetoexittheindustrywhenrevenuesarelessallcosts(price<averagecost).22Copyright?2009PearsonAddison-Wesley.Allrightsreserved.MonopolisticCompetitionandTradeBecausetradeincreasesmarketsize,tradeispredictedtodecreaseaveragecostinanindustrydescribedbymonopolisticcompetition.Industrysalesincreasewithtradeleadingtodecreasedaveragecosts:AC=F(n/S)+cBecausetradeincreasesthevarietyofgoodsthatconsumerscanbuyundermonopolisticcompetition,itincreasesthewelfareofconsumers.Andbecauseaveragecostsdecrease,consumerscanalsobenefitfromadecreasedprice.23Copyright?2009PearsonAddison-Wesley.Allrightsreserved.Fig.6-4:EffectsofaLargerMarket24Copyright?2009PearsonAddison-Wesley.Allrightsreserved.Monopolistic

CompetitionandTrade(cont.)Asaresultoftrade,thenumberoffirmsinanewinternationalindustryispredictedtoincreaserelativetoeachnationalmarket.Butitisuncleariffirmswilllocateinthedomesticcountryorforeigncountries.25Copyright?2009PearsonAddison-Wesley.Allrightsreserved.Monopolistic

CompetitionandTrade(cont.)Hypotheticalexampleofgainsfromtrade

inanindustrywithmonopolisticcompetitionDomesticmarketbeforetradeForeignmarketbeforetradeIntegratedmarketaftertradeIndustrysalesNumberoffirmsSalesperfirmAveragecostPrice900,0006150,00010,00010,0001,600,0008200,0008,7508,7502,500,00010250,0008,0008,00026Copyright?2009PearsonAddison-Wesley.Allrightsreserved.Inter-industryTradeAccordingtotheHeckscher-OhlinmodelorRicardianmodel,countriesspecializeinproduction.Tradeoccursonlybetweenindustries:inter-industrytradeInaHeckscher-Ohlinmodelsupposethat:Thecapitalabundantdomesticeconomyspecializesintheproductionofcapitalintensivecloth,whichisimportedbytheforeigneconomy.Thelaborabundantforeigneconomyspecializesintheproductionoflaborintensivefood,whichisimportedbythedomesticeconomy.27Copyright?2009PearsonAddison-Wesley.Allrightsreserved.Fig.6-6:TradeinaWorldWithout

IncreasingReturns28Copyright?2009PearsonAddison-Wesley.Allrightsreserved.Intra-industryTradeSupposenowthattheglobalclothindustryisdescribedbythemonopolisticcompetitionmodel.Becauseofproductdifferentiation,supposethateachcountryproducesdifferenttypesofcloth.Becauseofeconomiesofscale,largemarketsaredesirable:theforeigncountryexportssomeclothandthedomesticcountryexportssomecloth.Tradeoccurswithintheclothindustry:intra-industrytrade29Copyright?2009PearsonAddison-Wesley.Allrightsreserved.Intra-industryTrade(cont.)Ifdomesticcountryiscapitalabundant,itstillhasacomparativeadvantageincloth.Itshouldthereforeexportmorecloththanitimports.Supposethatthetradeinthefoodindustrycontinuestobedeterminedbycomparativeadvantage.30Copyright?2009PearsonAddison-Wesley.Allrightsreserved.Fig.6-7:TradewithIncreasingReturnsandMonopolisticCompetition31Copyright?2009PearsonAddison-Wesley.Allrightsreserved.Inter-industryandIntra-industryTradeGainsfrominter-industrytradereflectcomparativeadvantage.Gainsfromintra-industrytradereflecteconomiesofscale(lowercosts)andwiderconsumerchoices.Themonopolisticcompetitionmodeldoesnotpredictinwhichcountryfirmslocate,butacomparativeadvantageinproducingthedifferentiatedgoodwilllikelycauseacountrytoexportmoreofthatgoodthanitimports.32Copyright?2009PearsonAddison-Wesley.Allrightsreserved.Inter-industryand

Intra-industryTrade(cont.)Therelativeimportanceofintra-industrytradedependsonhowsimilarcountriesare.Countrieswithsimilarrelativeamountsoffactorsofproductionarepredictedtohaveintra-industrytrade.Countrieswithdifferentrelativeamountsoffactorsofproductionarepredictedtohaveinter-industrytrade.Unlikeinter-industrytradeintheHeckscher-Ohlinmodel,incomedistributioneffectsarenotpredictedtooccurwithintra-industrytrade.33Copyright?2009PearsonAddison-Wesley.Allrightsreserved.Inter-industryand

Intra-industryTrade(cont.)About25%ofworldtradeisintra-industrytradeaccordingtostandardindustrialclassifications.Butsomeindustrieshavemoreintra-industrytradethanothers:thoseindustriesrequiringrelativelylargeamountsofskilledlabor,technology,andphysicalcapitalexhibitintra-industrytradefor

theU.S.Countrieswithsimilarrelativeamountsofskilledlabor,technology,andphysicalcapitalengageinalargeamountofintra-industrytradewiththeU.S.34Copyright?2009PearsonAddison-Wesley.Allrightsreserved.Table6-3:IndexesofIntraindustryTradeforU.S.Industries,1993Note:anindexof1meansthatalltradeisintra-industrytrade.Anindexof0meansthatalltradeisinter-industrytrade.35Copyright?2009PearsonAddison-Wesley.Allrightsreserved.DumpingDumpingisthepracticeofchargingalowerpriceforexportedgoodsthanforgoodssolddomestically.Dumpingisanexampleofpricediscrimination:

thepracticeofchargingdifferentcustomersdifferentprices.Pricediscriminationanddumpingmayoccuronlyifimperfectcompetitionexists:firmsareabletoinfluencemarketprices.marketsaresegmentedsothatgoodsarenoteasilyboughtinonemarketandresoldinanother.36Copyright?2009PearsonAddison-Wesley.Allrightsreserved.Dumping(cont.)Dumpingmaybeaprofitmaximizingstrategybecauseofdifferencesinforeignanddomesticmarkets.Onedifferenceisthatdomesticfirmsusuallyhavealargershareofthedomesticmarketthantheydoofforeignmarkets.Becauseoflessmarketdominanceandmorecompetitioninforeignmarkets,foreignsalesareusuallymoreresponsivetopricechangesthandomesticsales.Domesticfirmsmaybeabletochargeahighpriceinthedomesticmarketbutmustchargealowpriceonexportsifforeignconsumersaremoreresponsivetopricechanges.37Copyright?2009PearsonAddison-Wesley.Allrightsreserved.Dumping(cont.)Wedrawadiagramofhowdumpingoccurswhenafirmisamonopolistinthedomesticmarketbutmustcompeteinforeignmarkets.Becausethefirmisamonopolistinthedomesticmarket,thedemandfunctionthatitfacesinthedomesticmarketisdownwardsloping,andmarginalrevenuefromadditionaloutputisalwayslessthanauniformpriceforallunitsofoutput.Becausethefirmcompetesinforeignmarkets,thedemandfunctionthatitfacesinforeignmarketsishorizontal,representingthefactthatexportsareveryresponsivetosmallpricechanges.38Copyright?2009PearsonAddison-Wesley.Allrightsreserved.Fig.6-8:Dumping39Copyright?2009PearsonAddison-Wesley.Allrightsreserved.Dumping(cont.)Tomaximizeprofits,thefirmshouldsellalimitedamountinthedomesticmarketatahighpricePDOM,butsellinforeignmarketsatalowpricePFOR.SincemorecanalwaysbesoldatPFOR,thefirmshouldsellitsproductsatahighpriceinthedomesticmarketuntilmarginalrevenuetherefallstoPFOR.Thereafter,itshouldsellexportsatPFORuntilmarginalcostsexceedthisprice.Inthiscase,dumpingisaprofit-maximizingstrategy.40Copyright?2009PearsonAddison-Wesley.Allrightsreserved.ProtectionismandDumpingDumping(aswellaspricediscriminationindomesticmarkets)iswidelyregardedasunfair.AUSfirmmayappealtotheCommerceDepartmenttoinvestigateifdumpingbyforeignfirmshasinjuredtheUSfirm.TheCommerceDepartmentmayimposean“anti-dumpingduty,”ortax,asaprecautionagainstpossibleinjury.Thistaxequalsthedifferencebetweentheactualand“fair”priceofimports,where“fair”means“pricetheproductisnormallysoldatinthemanufacturer'sdomesticmarket.”41Copyright?2009PearsonAddison-Wesley.Allrightsreserved.ProtectionismandDumping(cont.)NexttheInternationalTradeCommission(ITC)determinesifinjurytotheU.S.firmhasoccurredorislikelytooccur.IftheITCdeterminesthatinjuryhasoccurredorislikelytooccur,theanti-dumpingdutyremainsinplace.See/trade_remedy/731_ad_701_cvd/index.htm42Copyright?2009PearsonAddison-Wesley.Allrightsreserved.ExternalEconomiesofScaleIfexternaleconomiesexist,acountrythathasalargeindustrywillhavelowcostsofproducingthatindustry’sgoodorservice.Externaleconomiesmayexistforafewreasons:43Copyright?2009PearsonAddison-Wesley.Allrightsreserved.ExternalEconomiesofScale(cont.)Specializedequipmentorservicesmay

beneededfortheindustry,butareonlysuppliedbyotherfirmsiftheindustryislargeandconcentrated.Forexample,SiliconValleyinCaliforniahasalargeconcentrationsiliconchipcompanies,whichareservicedbycompaniesthatmakespecialmachinesformanufacturingsiliconchips.Thesemachinesarecheaperandmore

easilyavailableforSiliconValleyfirmsthanforfirmselsewhere.44Copyright?2009PearsonAddison-Wesley.Allrightsreserved.ExternalEconomiesofScale(cont.)Laborpooling:alargeandconcentratedindustrymayattractapoolofworkers,reducingemployeesearchandhiringcostsforeachfirm.Knowledgespillovers:workersfromdifferentfirmsmaymoreeasilyshareideasthatbenefiteachfirmwhenalargeandconcentratedindustryexists.45Copyright?2009PearsonAddison-Wesley.Allrightsreserved.ExternalEconomiesofScaleandTradeIfexternaleconomiesexist,thepatternoftrademaybeduetohistoricalaccidents:countriesthatstartaslargeproducersincertainindustriestendtoremainlargeproducersevenifanothercountrycouldpotentiallyproducemorecheaply.46Copyright?2009PearsonAddison-Wesley.Allrightsreserved.Fig.6-9:ExternalEconomicsandSpecialization47Copyright?2009PearsonAddison-Wesley.Allrightsreserved.ExternalEconomiesofScaleandTrade(cont.)Tradebasedonexternaleconomieshasanambiguouseffectonnationalwelfare.Theremaybegainstotheworldeconomybyconcentratingproductionofindustrieswith

externaleconomies.Butthereisnoguaranteethattherightcountrywillproduceagoodsubjecttoexternaleconomies.Itisevenpossiblethatacountryisworseoffwithtradethanitwouldhavebeenwithouttrade:acountrymaybebetteroffifitproduceseverythingforitsdomesticmarketratherthanpayforimports.48Copyright?2009PearsonAddison-Wesley.Allrightsreserved.Fig.6-10:ExternalEconomicsandLossesfromTrade49Copyright?2009PearsonAddison-Wesley.Allrightsreserved.ExternalEconomiesofScaleandTrade(cont.)ExternaleconomiesmayalsobeimportantforinterregionaltradewithinacountryManymovieproducersarelocatedinLosAngeleswhichproducemoviesforconsumersthroughouttheU.S.ManyfinancialfirmsarelocatedinNewYorkwhichprovidefinancialservicesforconsumersthroughouttheU.S.Ifexternaleconomiesexist,thepatternoftrademaybeduetohistoricalaccidents:regionsthatstartaslargeproducersincertainindustriestendtoremainlargeproducersevenifanotherregioncouldpotentiallyproducemorecheaply.50Copyright?2009PearsonAddison-Wesley.Allrightsreserved.ExternalEconomiesofScaleandTrade(cont.)Morebroadly,economicgeographyreferstothestudyofinternationaltrade,interregionaltradeandtheorganizationofeconomicactivityinmetropolitanandruralareas.Economicgeographystudieshowhumanstransactwitheachotheracrossspace.Communicationchangessuchastheinternet,e-mail,textmail,videoconferencing,mobilephones(aswellasmoderntransportation)arechanginghowhumanstransactwitheachotheracrossspace.51Copyright?2009PearsonAddison-Wesley.Allrightsreserved.ExternalEconomiesofScaleandTrade(cont.)Wehaveconsideredcaseswhereexternaleconomiesdependontheamountofcurrentoutputatapointintime.Butexternaleconomiesmayalsodependontheamountofcumulativeoutputovertime.Dynamicincreasingreturnstoscaleexistifaveragecostsfallascumulativeoutputovertimerises.Dynamicincreasingreturnstoscaleimplydynamicexternaleconomiesofscale.52Copyright?2009PearsonAddison-Wesley.Allrightsreserved.ExternalEconomies

ofScaleandTrade(cont.)Dynamicincreasingreturnstoscalecouldariseifthecostofproductiondependsontheaccumulationofknowledgeandexperience,whichdependontheproductionprocess

overtime.Agraphicalrepresentationofdynamicincreasingreturnstoscaleiscalledalearningcurve.53Copyright?2009PearsonAddison-Wesley.Allrightsreserved.Fig.6-11:TheLearningCurve54Copyright?2009PearsonAddison-Wesley.Allrightsreserved.ExternalEconomies

ofScaleandTrade(cont.)Likeexternaleconomiesofscaleatapointintime,dynamicincreasingreturnstoscalecanlockinaninitialadvantageoraheadstartinanindustry.Likeexternaleconomiesofscaleatapointintime,dynamicincreasingreturnstoscalecanbeusedtojustifyprotectionism.Temporaryprotectionofindustriesenablesthemtogainexperience:infantindustryargument.Buttemporaryisoftenforalongtime,anditishardtoidentifywhenexternaleconomiesofscalereallye