CHEconomiesofScaleImperfectCompetitionandInternationalTrade發(fā)展經(jīng)濟學廈門大學陳濤實用

會計學1CHEconomiesofScaleImperfectCompetitionandInternationalTrade發(fā)展經(jīng)濟學廈門大學陳濤實用Copyright?2003PearsonEducation,Inc.Slide6-2IntroductionCountriesengageininternationaltradefortwobasicreasons:Countriestradebecausetheydiffereitherintheirresourcesorintechnology.Countriestradeinordertoachievescaleeconomiesorincreasingreturnsinproduction.Twomodelsofinternationaltradeinwhicheconomiesofscaleandimperfectcompetitionplayacrucialrole:MonopolisticcompetitionmodelDumpingmodel第1頁/共58頁Copyright?2003PearsonEducation,Inc.Slide6-3EconomiesofScaleandInternationalTrade:AnOverviewModelsoftradebasedoncomparativeadvantage(e.g.Ricardianmodel)usedtheassumptionsofconstantreturnstoscaleandperfectcompetition:Increasingtheamountofallinputsusedintheproductionofanycommoditywillincreaseoutputofthatcommodityinthesameproportion.Inpractice,manyindustriesarecharacterizedbyeconomiesofscale(alsoreferredtoasincreasingreturns).Productionismostefficient,thelargerthescaleatwhichittakesplace.第2頁/共58頁Copyright?2003PearsonEducation,Inc.Slide6-4Underincreasingreturnstoscale:Outputgrowsproportionatelymorethantheincreaseinallinputs.Averagecosts(costsperunit)declinewiththesizeofthemarket.EconomiesofScaleandInternationalTrade:AnOverview第3頁/共58頁Copyright?2003PearsonEducation,Inc.Slide6-5EconomiesofScaleandInternationalTrade:AnOverviewTable6-1:RelationshipofInputtoOutputforaHypotheticalIndustry第4頁/共58頁Copyright?2003PearsonEducation,Inc.Slide6-6EconomiesofScaleand

MarketStructureEconomiesofscalecanbeeither:ExternalThecostperunitdependsonthesizeoftheindustrybutnotnecessarilyonthesizeofanyonefirm.Anindustrywilltypicallyconsistofmanysmallfirmsandbeperfectlycompetitive.InternalThecostperunitdependsonthesizeofanindividualfirmbutnotnecessarilyonthatoftheindustry.Themarketstructurewillbeimperfectlycompetitivewithlargefirmshavingacostadvantageoversmall.Bothtypesofscaleeconomiesareimportantcausesofinternationaltrade.第5頁/共58頁Copyright?2003PearsonEducation,Inc.Slide6-7ImperfectcompetitionFirmsareawarethattheycaninfluencethepriceoftheirproduct.Theyknowthattheycansellmoreonlybyreducingtheirprice.Eachfirmviewsitselfasapricesetter,choosingthepriceofitsproduct,ratherthanapricetaker.Thesimplestimperfectlycompetitivemarketstructureisthatofapuremonopoly,amarketinwhichafirmfacesnocompetition.TheTheoryof

ImperfectCompetition第6頁/共58頁Copyright?2003PearsonEducation,Inc.Slide6-8Monopoly:ABriefReviewMarginalrevenue

TheextrarevenuethefirmgainsfromsellinganadditionalunitItscurve,MR,alwaysliesbelowthedemandcurve,D.Inordertosellanadditionalunitofoutputthefirmmustlowerthepriceofallunitssold(notjustthemarginalone).TheTheoryof

ImperfectCompetition第7頁/共58頁Copyright?2003PearsonEducation,Inc.Slide6-9TheTheoryof

ImperfectCompetitionFigure6-1:MonopolisticPricingandProductionDecisionsDCost,CandPrice,PQuantity,QMonopolyprofitsACPMQMMRMCAC第8頁/共58頁Copyright?2003PearsonEducation,Inc.Slide6-10MarginalRevenueandPriceMarginalrevenueisalwayslessthantheprice.Therelationshipbetweenmarginalrevenueandpricedependsontwothings:HowmuchoutputthefirmisalreadysellingTheslopeofthedemandcurveIttellsushowmuchthemonopolisthastocuthispricetosellonemoreunitofoutput.TheTheoryof

ImperfectCompetition第9頁/共58頁Copyright?2003PearsonEducation,Inc.Slide6-11Assumethatthedemandcurvethefirmfacesisastraightline:

Q=A–B

x

P (6-1)ThentheMRthatthefirmfacesisgivenby:

MR=P–Q/B (6-2)AverageandMarginalCostsAverageCost(AC)is

totalcostdividedbyoutput.MarginalCost(MC)is

theamountitcoststhefirmtoproduceoneextraunit.TheTheoryof

ImperfectCompetition第10頁/共58頁Copyright?2003PearsonEducation,Inc.Slide6-12Whenaveragecostsdeclineinoutput,marginalcostisalwayslessthanaveragecost.Supposethecostsofafirm,C,taketheform:

C=F+c

x

Q (6-3)Thisisalinearcostfunction.Thefixedcostinalinearcostfunctiongivesrisetoeconomiesofscale,becausethelargerthefirm’soutput,thelessisfixedcostperunit.Thefirm’saveragecostsisgivenby:

AC=C/Q=F/Q+c(6-4)TheTheoryof

ImperfectCompetition第11頁/共58頁Copyright?2003PearsonEducation,Inc.Slide6-13Figure6-2:AverageVersusMarginalCostTheTheoryof

ImperfectCompetitionAveragecostMarginalcost120345624681012141618202224CostperunitOutput第12頁/共58頁Copyright?2003PearsonEducation,Inc.Slide6-14MonopolisticCompetitionOligopoly

Internaleconomiesgenerateanoligopolymarketstructure.Thereareseveralfirms,eachofwhichislargeenoughtoaffectprices,butnonewithanuncontestedmonopoly.Strategicinteractionsamongoligopolistshavebecomeimportant.Eachfirmdecidesitsownactions,takingintoaccounthowthatdecisionmightinfluenceitsrival’sactions.TheTheoryof

ImperfectCompetition第13頁/共58頁Copyright?2003PearsonEducation,Inc.Slide6-15MonopolisticcompetitionAspecialcaseofoligopolyTwokeyassumptionsaremadetogetaroundtheproblemofinterdependence:Eachfirmisassumedtobeabletodifferentiateitsproductfromitsrivals.Eachfirmisassumedtotakethepriceschargedbyitsrivalsasgiven.TheTheoryof

ImperfectCompetition第14頁/共58頁Copyright?2003PearsonEducation,Inc.Slide6-16Arethereanymonopolisticallycompetitiveindustriesintherealworld?Someindustriesmaybereasonableapproximations(e.g.,theautomobileindustryinEurope)Themainappealofthemonopolisticcompetitionmodelisnotitsrealism,butitssimplicity.TheTheoryof

ImperfectCompetition第15頁/共58頁Copyright?2003PearsonEducation,Inc.Slide6-17AssumptionsoftheModelImagineanindustryconsistingofanumberoffirmsproducingdifferentiatedproducts.Weexpectafirm:Tosellmorethelargerthetotaldemandforitsindustry’sproductandthehigherthepriceschargedbyitsrivalsToselllessthegreaterthenumberoffirmsintheindustryandthehigheritsownpriceTheTheoryof

ImperfectCompetition第16頁/共58頁Copyright?2003PearsonEducation,Inc.Slide6-18

where:Qisthefirm’ssalesSisthetotalsalesoftheindustrynisthenumberoffirmsintheindustrybisaconstanttermrepresentingtheresponsivenessofafirm’ssalestoitspricePisthepricechargedbythefirmitselfAparticularequationforthedemandfacingafirmthathasthesepropertiesis:

Q=S

x[1/n–b

x(P–P)](6-5)TheTheoryof

ImperfectCompetitionPistheaveragepricechargedbyitscompetitors第17頁/共58頁Copyright?2003PearsonEducation,Inc.Slide6-19MarketEquilibriumAllfirmsinthisindustryaresymmetricThedemandfunctionandcostfunctionareidenticalforallfirms.Themethodfordeterminingthenumberoffirmsandtheaveragepricechargedinvolvesthreesteps:Wederivearelationshipbetweenthenumberoffirmsandtheaveragecostofatypicalfirm.Wederivearelationshipbetweenthenumberoffirmsandthepriceeachfirmcharges.Wederivetheequilibriumnumberoffirmsandtheaveragepricethatfirmscharge.TheTheoryof

ImperfectCompetition第18頁/共58頁Copyright?2003PearsonEducation,Inc.Slide6-20ThenumberoffirmsandaveragecostHowdotheaveragecostsdependonthenumberoffirmsintheindustry?TheTheoryof

ImperfectCompetitionUndersymmetry,P=P,equation(6-5)tellsusthat

Q=S/nbutequation(6-4)showsusthattheaveragecostdependsinverselyonafirm’soutput.Weconcludethataveragecostdependsonthesizeofthemarketandthenumberoffirmsintheindustry: AC=F/Q+c=n

x

F/S+c(6-6)Themorefirmsthereareintheindustrythehigheristheaveragecost.第19頁/共58頁Copyright?2003PearsonEducation,Inc.Slide6-21PPCostC,andPrice,PNumberoffirms,nCCP3AC3n3n1AC1n2AC2EFigure6-3:EquilibriuminaMonopolisticallyCompetitiveMarketTheTheoryof

ImperfectCompetitionP2,P1第20頁/共58頁Copyright?2003PearsonEducation,Inc.Slide6-22ThenumberoffirmsandthepriceThepricethetypicalfirmchargesdependsonthenumberoffirmsintheindustry.Themorefirms,themorecompetition,andhencethelowertheprice.Inthemonopolisticcompetitionmodelfirmsareassumedtotakeeachothers’pricesasgiven.TheTheoryof

ImperfectCompetitionIfeachfirmtreatsPasgiven,wecanrewritethedemandcurve(6-5)intheform: Q=(S/n+S

x

b

x

P)–S

x

b

x

P(6-7)第21頁/共58頁Copyright?2003PearsonEducation,Inc.Slide6-23Profit-maximizingfirmssetmarginalrevenueequaltotheirmarginalcost,c.ThisgeneratesanegativerelationshipbetweenthepriceandthenumberoffirmsinthemarketwhichisthePPcurve: P=c+1/(b

x

n) (6-10)Themorefirmsthereareintheindustry,thelowerthepriceeachfirmwillcharge.TheTheoryof

ImperfectCompetition第22頁/共58頁Copyright?2003PearsonEducation,Inc.Slide6-24TheequilibriumnumberoffirmsThedownward-slopingcurvePPshowsthatthemorefirms,thelowerthepriceeachfirmwillcharge.Themorefirms,themorecompetitioneachfirmfaces.Theupward-slopingcurveCCtellsusthatthemorefirmsthereare,thehighertheaveragecostofeachfirm.Ifthenumberoffirmsincreases,eachfirmwillsellless,sofirmswillnotbeabletomoveasfardowntheiraveragecostcurve.TheTheoryof

ImperfectCompetition第23頁/共58頁Copyright?2003PearsonEducation,Inc.Slide6-25LimitationsoftheMonopolisticCompetitionModelTwokindsofbehaviorariseinthegeneraloligopolysettingthatareexcludedbyassumptionfromthemonopolisticcompetitionmodel:Collusivebehavior:CanraisetheprofitsofallfirmsattheexpenseofconsumersMaybemanagedthroughexplicitagreementsorthroughtacitcoordinationstrategiesStrategicbehavior:IsadoptedbyfirmstoaffectthebehaviorofcompetitorsinadesirablewayDeterspotentialrivalsfromenteringanindustryTheTheoryof

ImperfectCompetition第24頁/共58頁Copyright?2003PearsonEducation,Inc.Slide6-26Themonopolisticcompetitionmodelcanbeusedtoshowhowtradeleadsto:IncreasedmarketsizeMutualgainsfromaintegratedmarketEconomicsofscaleintra-industrytradeMonopolisticCompetitionandTrade第25頁/共58頁Copyright?2003PearsonEducation,Inc.Slide6-27Figure6-4:EffectsofaLargerMarketCostC,andPrice,PNumberoffirms,nCC1n1

P11PPn2P22CC2MonopolisticCompetitionandTrade第26頁/共58頁Copyright?2003PearsonEducation,Inc.Slide6-28MonopolisticCompetitionandTradeCC: AC=F/Q+c=n

x

F/S+c

PP:

P=c+1/(b

x

n)

第27頁/共58頁Copyright?2003PearsonEducation,Inc.Slide6-29GainsfromanIntegratedMarket:ANumericalExampleExample:Supposethatautomobilesareproducedbyamonopolisticallycompetitiveindustry.Assumethefollowing:b=1/30,000,F=$750,000,000,c=$5000Therearetwocountries(HomeandForeign)thathavethesamecostsofautomobileproduction.Annualsalesofautomobilesare900,000atHomeand1.6millionatForeign.MonopolisticCompetitionandTrade第28頁/共58頁Copyright?2003PearsonEducation,Inc.Slide6-30Figure6-5:EquilibriumintheAutomobileMarketMonopolisticCompetitionandTrade第29頁/共58頁Copyright?2003PearsonEducation,Inc.Slide6-31Figure6-5:ContinuedMonopolisticCompetitionandTrade第30頁/共58頁Copyright?2003PearsonEducation,Inc.Slide6-32Figure6-5:ContinuedMonopolisticCompetitionandTrade第31頁/共58頁Copyright?2003PearsonEducation,Inc.Slide6-33Table6-2:HypotheticalExampleofGainsfromMarketIntegrationMonopolisticCompetitionandTrade第32頁/共58頁Copyright?2003PearsonEducation,Inc.Slide6-34EconomiesofScaleandComparativeAdvantageAssumptions:Therearetwocountries:Home(thecapital-abundantcountry)andForeign.Therearetwoindustries:manufactures(thecapital-intensiveindustry)andfood.Neithercountryisabletoproducethefullrangeofmanufacturedproductsbyitselfduetoeconomiesofscale.MonopolisticCompetitionandTrade第33頁/共58頁Copyright?2003PearsonEducation,Inc.Slide6-35Figure6-6:TradeinaWorldWithoutIncreasingReturnsHome(capitalabundant)Foreign(laborabundant)ManufacturesFoodMonopolisticCompetitionandTrade第34頁/共58頁Copyright?2003PearsonEducation,Inc.Slide6-36Ifmanufacturesisamonopolisticallycompetitivesector,worldtradeconsistsoftwoparts:IntraindustrytradeTheexchangeofmanufacturesformanufacturesInterindustrytradeTheexchangeofmanufacturesforfoodMonopolisticCompetitionandTrade第35頁/共58頁Copyright?2003PearsonEducation,Inc.Slide6-37Figure6-7:TradewithIncreasingReturnsandMonopolisticCompetitionHome(capitalabundant)Foreign(laborabundant)ManufacturesFoodInterindustrytradeIntraindustrytradeMonopolisticCompetitionandTrade第36頁/共58頁Copyright?2003PearsonEducation,Inc.Slide6-38Maindifferencesbetweeninterindustryandintraindustrytrade:Interindustrytradereflectscomparativeadvantage,whereasintraindustrytradedoesnot.Thepatternofintraindustrytradeitselfisunpredictable,whereasthatofinterindustrytradeisdeterminedbyunderlyingdifferencesbetweencountries.Therelativeimportanceofintraindustryandinterindustrytradedependsonhowsimilarcountriesare.MonopolisticCompetitionandTrade第37頁/共58頁Copyright?2003PearsonEducation,Inc.Slide6-39TheSignificanceofIntraindustryTradeAboutone-fourthofworldtradeconsistsofintra-industrytrade.Intra-industrytradeplaysaparticularlylargeroleinthetradeinmanufacturedgoodsamongadvancedindustrialnations,whichaccountsformostofworldtrade.MonopolisticCompetitionandTrade第38頁/共58頁Copyright?2003PearsonEducation,Inc.Slide6-40Table6-3:IndexesofIntraindustryTradeforU.S.Industries,1993MonopolisticCompetitionandTrade第39頁/共58頁Copyright?2003PearsonEducation,Inc.Slide6-41TheEconomicsofDumpingPricediscriminationThepracticeofchargingdifferentcustomersdifferentpricesDumpingThemostcommonformofpricediscriminationininternationaltradeApricingpracticeinwhichafirmchargesalowerpriceforanexportedgoodthanitdoesforthesamegoodsolddomesticallyDumping第40頁/共58頁Copyright?2003PearsonEducation,Inc.Slide6-42Dumpingcanoccuronlyiftwoconditionsaremet:ImperfectlycompetitiveindustrySegmentedmarketsGiventheseconditions,amonopolisticfirmmayfindthatitisprofitabletoengageindumping.Dumping第41頁/共58頁Copyright?2003PearsonEducation,Inc.Slide6-43Figure6-8:DumpingDumpingExportsDomesticsalesCost,CandPrice,PQuantitiesproducedanddemanded,QMCDFOR=MRFORMRDOMDDOM2PFORPDOMQDOMQMONOPOLYTotaloutput13第42頁/共58頁Copyright?2003PearsonEducation,Inc.Slide6-44ReciprocalDumpingAsituationinwhichdumpingleadstotwo-waytradeinthesameproductItincreasesthevolumeoftradeingoodsthatarenotquiteidentical.Itsnetwelfareeffectisambiguous:Itwastesresourcesintransportation.Itcreatessomecompetition.Dumping第43頁/共58頁Copyright?2003PearsonEducation,Inc.Slide6-45TheTheoryofExternalEconomiesEconomiesofscalethatoccurattheleveloftheindustryinsteadofthefirmarecalledexternaleconomies.Therearethreemainreasonswhyaclusteroffirmsmaybemoreefficientthananindividualfirminisolation:SpecializedsuppliersLabormarketpoolingKnowledgespillovers第44頁/共58頁Copyright?2003PearsonEducation,Inc.Slide6-46SpecializedSuppliersInmanyindustries,theproductionofgoodsandservicesandthedevelopmentofnewproductsrequirestheuseofspecializedequipmentorsupportservices.Anindividualcompanydoesnotprovidealargeenoughmarketfortheseservicestokeepthesuppliersinbusiness.Alocalizedindustrialclustercansolvethisproblembybringingtogethermanyfirmsthatprovidealargeenoughmarkettosupportspecializedsuppliers.ThisphenomenonhasbeenextensivelydocumentedinthesemiconductorindustrylocatedinSiliconValley.TheTheoryofExternalEconomies第45頁/共58頁Copyright?2003PearsonEducation,Inc.Slide6-47LaborMarketPoolingAclusteroffirmscancreateapooledmarketforworkerswithhighlyspecializedskills.Itisanadvantagefor:ProducersTheyarelesslikelytosufferfromlaborshortages.WorkersTheyarelesslikelytobecomeunemployed.TheTheoryofExternalEconomies第46頁/共58頁Copyright?2003PearsonEducation,Inc.Slide6-48KnowledgeSpilloversKnowledgeisoneoftheimportantinputfactorsinhighlyinnovativeindustries.Thespecializedknowledgethatiscrucialtosuccessininnovativeindustriescomesfrom:ResearchanddevelopmenteffortsReverseengineeringInformalexchangeofinformationandideasTheTheoryofExternalEconomies第47頁/共58頁Copyright?2003PearsonEducation,Inc.Slide6-49ExternalEconomiesandIncreasingReturnsExternaleconomiescangiverisetoincreasingreturnstoscaleatthelevelofthenationalindustry.Forward-fallingsupplycurveThelargertheindustry’soutput,thelowerthepriceatwhichfirmsarewillingtoselltheiroutput.TheTheoryofExternalEconomies第48頁/共58頁Copyright?2003PearsonEducation,Inc.Slide6-50ExternalEconomiesandthePatterofTradeAcountrythathaslargeproductioninsomeindustrywilltendtohavelowcostsofproducingthatgood.Countriesthatstartoutaslargeproducersincertainindustriestendtoremainlargeproducersevenifsomeothercountrycouldpotentiallyproducethegoodsmorecheaply.Figure6-9illustratesacasewhereapatternofspecializationestablishedbyhistoricalaccidentispersistent.ExternalEconomiesandInternationalTrade第49頁/共58頁Copyright?2003PearsonEducation,Inc.Slide6-51Figure6-9:ExternalEconomiesandSpecializationExternalEconomiesandInternationalTradeACSWISSQ1P1Price,cost(perwatch)QuantityofwatchesproducedanddemandedACTHAI21C0D第50頁/共58頁Copyright?2003PearsonEducation,Inc.Slide6-52TradeandWelfarewithExternalEconomiesTradebasedonexternaleconomieshasmoreambiguouseffectsonnationalwelfarethaneithertradebasedoncomparativeadvantageortradebasedoneconomiesofscaleatthelevelofthefirm.AnexampleofhowacountrycanactuallybeworseoffwithtradethanwithoutisshowninFigure6-10.ExternalEconomiesandInternationalTrade第51頁/共58頁Copyright?2003PearsonEducation,Inc.Slide6-53Figure6-10:ExternalEconomiesandLossesfromTradeExternalEconomiesandInternationalTradeACSWISSP1Price,cost(perwatch)QuantityofwatchesproducedanddemandedACTHAI21C0DTHAIDWO