寡头垄断与粘性价格

OligopolyChapter16-2ModelsofOligopolyBehavior•Nosinglegeneralmodelofoligopolybehaviorexists.Oligopoly•Anoligopolyisamarketstructurecharacterizedby:–Fewfirms–Eitherstandardizedordifferentiatedproducts–DifficultentryInterdependence•Akeycharacteristicofoligopoliesisthateachfirmcanaffectthemarket,makingeachfirm’schoicesdependentonthechoicesoftheotherfirms.Theyareinterdependent.CharacteristicsOligopoly•Oligopoliesaremadeupofasmallnumberofmutuallyinterdependentfirms.•Eachfirmmusttakeintoaccounttheexpectedreactionofotherfirms.Interdependence•Theimportanceofinterdependenceisthatitleadstostrategicbehavior.•StrategicbehavioristhebehaviorthatoccurswhenwhatisbestforAdependsuponwhatBdoes,andwhatisbestforBdependsuponwhatAdoes.•Oligopolisticbehaviorincludesbothruthlesscompetitionandcooperation.GameTheory•Strategicbehaviorhasbeenanalyzedusingthemathematicaltechniquesofgametheory.•Gametheoryprovidesadescriptionofoligopolisticbehaviorasaseriesofstrategicmovesandcountermoves.CharacteristicsofOligopoly•Oligopoliesaremadeupofasmallnumberoffirmsinanindustry•Oligopolisticfirmsaremutuallyinterdependent•Inanydecisionafirmmakes,itmusttakeintoaccounttheexpectedreactionofotherfirms•Oligopoliescanbecollusiveornoncollusive•Firmsmayengageinstrategicdecisionmakingwhereeachfirmtakesexplicitaccountofarival’sexpectedresponsetoadecisionitismaking16-8ModelsofOligopolyBehavior•Thereisnosinglemodelofoligopolybehavior•Thecartelmodeliswhenacombinationoffirmsactsasifitwereasinglefirmandamonopolypriceisset•Anoligopolymodelcantaketwoextremes:•Thecontestablemarketmodelisamodelofoligopolieswherebarrierstoentryandexit,notmarketstructure,determinepriceandoutputdecisionsandacompetitivepriceisset•Othermodelsofoligopoliesgivepriceresultsbetweenthetwoextremes16-9TheCartelModel•Acartelmodelofoligopolyisamodelthatassumesthatoligopoliesactasiftheywereamonopolyandsetapricetomaximizeprofit•Outputquotasareassignedtoindividualmemberfirmssothattotaloutputisconsistentwithjointprofitmaximization•Ifoligopoliescanlimittheentryofotherfirms,theycanincreaseprofits16-10ImplicitPriceCollusion•Explicit(formal)collusionisillegalintheU.S.whileimplicit(informal)collusionispermitted•Implicitpricecollusionexistswhenmultiplefirmsmakethesamepricingdecisionseventhoughtheyhavenotconsultedwithoneanother•Sometimesthelargestormostdominantfirmtakestheleadinsettingpricesandtheothersfollow16-11WhyArePricesSticky?•Onecharacteristicofinformalcollusivebehavioristhatpricestendtobesticky–theydon’tchangefrequently•Informalcollusionisanimportantreasonwhypricesaresticky•Anotheristhekinkeddemandcurve•Ifafirmincreasesprice,otherswon’tgoalong,sodemandisveryelasticforpriceincreases•Ifafirmlowersprice,otherfirmsmatchthedecrease,sodemandisinelasticforpricedecreases16-12TheKinkedDemandCurveGraph•AgapintheMRcurveexists•AlargeshiftinmarginalcostisrequiredbeforefirmswillchangetheirpriceQPQMC1DMRPIfPincreases,otherswon’tgoalong,soDiselasticIfPdecreases,otherfirmsmatchthedecrease,soDisinelasticMC2Gap16-13TheContestableMarketModel•Thecontestablemarketmodelisamodelofoligopolieswherebarrierstoentryandexit,notmarketstructure,determinepriceandoutputdecisionsandacompetitivepriceisset•Eveniftheindustrycontainsonlyonefirm,itwillsetacompetitivepriceiftherearenobarrierstoentry•Muchofwhathappensinoligopolypricingisdependentonthespecificlegalstructurewithinwhichfirmsinteract16-14ComparingContestableMarketandCartelModels•Thecartelmodelisappropriateforoligopoliststhatcollude,setamonopolyprice,andpreventmarketentry•Thecontestablemarketmodeldescribesoligopoliesthatsetacompetitivepriceandhavenobarrierstoentry•Oligopolymarketsliebetweenthesetwoextremes•Bothmodelsusestrategicpricingdecisionswherefirmssettheirpricebasedontheexpectedreactionsofotherfirms16-15NewEntryasaLimitontheCartelizationStrategyandPriceWars•Pricewarsaretheresultofstrategicpricingdecisionsgonewild•Apredatorypricingstrategyinvolvestemporarilypushingthepricedowninordertodriveacompetitoroutofbusiness•Thethreatofoutsidecompetitionlimitsoligopoliesfromactingasacartel•Thethreatwillbemoreeffectiveiftheoutsidecompetitorismuchlargerthanthefirmsintheoligopoly16-16WhyArePricesSticky?•Whenthereisakinkinthedemandcurve,therehastobeagapinthemarginalrevenuecurve.•Thekinkeddemandcurveisnotatheoryofoligopolybutatheoryofstickyprices.D2TheKinkedDemandCurveD1MR2MR1PriceQuantity0QPabcdMC0MC1TheKinkedDemandCurveGameTheoryandStrategicDecisionMaking•Theprisoner’sdilemmaisawell-knowngamethatdemonstratesthedifficultyofcooperativebehaviorincertaincircumstances.GameTheoryandStrategicDecisionMaking•Intheprisoner’sdilemma,wheremutualtrustgetseachoneoutofthedilemma,confessingistherationalchoice.Prisoner’sDilemmaandaDuopolyExample•Theprisonersdilemmahasitssimplestapplicationwhentheoligopolyconsistsofonlytwofirms—aduopoly.Prisoner’sDilemmaandaDuopolyExample•Byanalyzingthestrategiesofbothfirmsunderallsituations,allpossibilitiesareplacedinapayoffmatrix.•Apayoffmatrixisaboxthatcontainstheoutcomesofastrategicgameundervariouscircumstances.FirmandIndustryDuopolyCooperativeEquilibriumPricePrice575$80