寡头垄断与粘性价格.ppt

Oligopoly Chapter16 2 ModelsofOligopolyBehavior Nosinglegeneralmodelofoligopolybehaviorexists Oligopoly Anoligopolyisamarketstructurecharacterizedby FewfirmsEitherstandardizedordifferentiatedproductsDifficultentry Interdependence Akeycharacteristicofoligopoliesisthateachfirmcanaffectthemarket makingeachfirm schoicesdependentonthechoicesoftheotherfirms Theyareinterdependent CharacteristicsOligopoly Oligopoliesaremadeupofasmallnumberofmutuallyinterdependentfirms Eachfirmmusttakeintoaccounttheexpectedreactionofotherfirms Interdependence Theimportanceofinterdependenceisthatitleadstostrategicbehavior StrategicbehavioristhebehaviorthatoccurswhenwhatisbestforAdependsuponwhatBdoes andwhatisbestforBdependsuponwhatAdoes Oligopolisticbehaviorincludesbothruthlesscompetitionandcooperation GameTheory Strategicbehaviorhasbeenanalyzedusingthemathematicaltechniquesofgametheory Gametheoryprovidesadescriptionofoligopolisticbehaviorasaseriesofstrategicmovesandcountermoves CharacteristicsofOligopoly Oligopoliesaremadeupofasmallnumberoffirmsinanindustry Oligopolisticfirmsaremutuallyinterdependent Inanydecisionafirmmakes itmusttakeintoaccounttheexpectedreactionofotherfirms Oligopoliescanbecollusiveornoncollusive Firmsmayengageinstrategicdecisionmakingwhereeachfirmtakesexplicitaccountofarival sexpectedresponsetoadecisionitismaking 16 8 ModelsofOligopolyBehavior Thereisnosinglemodelofoligopolybehavior Thecartelmodeliswhenacombinationoffirmsactsasifitwereasinglefirmandamonopolypriceisset Anoligopolymodelcantaketwoextremes Thecontestablemarketmodelisamodelofoligopolieswherebarrierstoentryandexit notmarketstructure determinepriceandoutputdecisionsandacompetitivepriceisset Othermodelsofoligopoliesgivepriceresultsbetweenthetwoextremes 16 9 TheCartelModel Acartelmodelofoligopolyisamodelthatassumesthatoligopoliesactasiftheywereamonopolyandsetapricetomaximizeprofit Outputquotasareassignedtoindividualmemberfirmssothattotaloutputisconsistentwithjointprofitmaximization Ifoligopoliescanlimittheentryofotherfirms theycanincreaseprofits 16 10 ImplicitPriceCollusion Explicit formal collusionisillegalintheU S whileimplicit informal collusionispermitted Implicitpricecollusionexistswhenmultiplefirmsmakethesamepricingdecisionseventhoughtheyhavenotconsultedwithoneanother Sometimesthelargestormostdominantfirmtakestheleadinsettingpricesandtheothersfollow 16 11 WhyArePricesSticky Onecharacteristicofinformalcollusivebehavioristhatpricestendtobesticky theydon tchangefrequently Informalcollusionisanimportantreasonwhypricesaresticky Anotheristhekinkeddemandcurve Ifafirmincreasesprice otherswon tgoalong sodemandisveryelasticforpriceincreasesIfafirmlowersprice otherfirmsmatchthedecrease sodemandisinelasticforpricedecreases 16 12 TheKinkedDemandCurveGraph AgapintheMRcurveexistsAlargeshiftinmarginalcostisrequiredbeforefirmswillchangetheirprice Q P Q MC1 D MR P IfPincreases otherswon tgoalong soDiselastic IfPdecreases otherfirmsmatchthedecrease soDisinelastic MC2 Gap 16 13 TheContestableMarketModel Thecontestablemarketmodelisamodelofoligopolieswherebarrierstoentryandexit notmarketstructure determinepriceandoutputdecisionsandacompetitivepriceisset Eveniftheindustrycontainsonlyonefirm itwillsetacompetitivepriceiftherearenobarrierstoentry Muchofwhathappensinoligopolypricingisdependentonthespecificlegalstructurewithinwhichfirmsinteract 16 14 ComparingContestableMarketandCartelModels Thecartelmodelisappropriateforoligopoliststhatcollude setamonopolyprice andpreventmarketentry Thecontestablemarketmodeldescribesoligopoliesthatsetacompetitivepriceandhavenobarrierstoentry Oligopolymarketsliebetweenthesetwoextremes Bothmodelsusestrategicpricingdecisionswherefirmssettheirpricebasedontheexpectedreactionsofotherfirms 16 15 NewEntryasaLimitontheCartelizationStrategyandPriceWars Pricewarsaretheresultofstrategicpricingdecisionsgonewild Apredatorypricingstrategyinvolvestemporarilypushingthepricedowninordertodriveacompetitoroutofbusiness Thethreatofoutsidecompetitionlimitsoligopoliesfromactingasacartel Thethreatwillbemoreeffectiveiftheoutsidecompetitorismuchlargerthanthefirmsintheoligopoly 16 16 WhyArePricesSticky Whenthereisakinkinthedemandcurve therehastobeagapinthemarginalrevenuecurve Thekinkeddemandcurveisnotatheoryofoligopolybutatheoryofstickyprices TheKinkedDemandCurve TheKinkedDemandCurve GameTheoryandStrategicDecisionMaking Theprisoner sdilemmaisawell knowngamethatdemonstratesthedifficultyofcooperativebehaviorincertaincircumstances GameTheoryandStrategicDecisionMaking Intheprisoner sdilemma wheremutualtrustgetseachoneoutofthedilemma confessingistherationalchoice Prisoner sDilemmaandaDuopolyExample Theprisonersdilemmahasitssimplestapplicationwhentheoligopolyconsistsofonlytwofirms aduopoly Prisoner sDilemmaandaDuopolyExample Byanalyzingthestrategiesofbothfirmsunderallsituations allpossibilitiesareplacedinapayoffmatrix Apayoffmatrixisaboxthatcontainstheoutcomesofastrategicgameundervariouscircumstances FirmandIndustryDuopolyCooperativeEquilibrium McGraw Hill Irwin 2004TheMcGraw HillCompanies Inc AllRightsReserved FirmandIndustryDuopolyEquilibriumWhenOneFirmCheats McGraw Hill Irwin 2004TheMcGraw HillCompanies Inc AllRightsReserved DuopolyandaPayoffMatrix Theduopolyisavariationoftheprisoner sdilemmagame Theresultscanbepresentedinapayoffmatrixthatcapturestheessenceoftheprisoner sdilemma ThePayoffMatrixofStrategicPricingDuopoly DominantStrategy Inanoligopoly firmstrytoachieveadominantstrategy astrategythatproducesbetterresultsnomatterwhatstrategyotherfirmsfollow Theinterdependenceofoligopoliesdecisionscanoftenleadtotheprisoner sdilemma Prisoner sDilemma ImplicitPriceCollusion FormalcollusionisillegalintheU S whileinformalcollusionispermitted Implicitpricecollusionexistswhenmultiplefirmsmakethesamepricingdecisionseventhoughtheyhavenotconsultedwithoneanother ImplicitPriceCollusion Sometimesthelargestormostdominantfirmtakestheleadinsettingpricesandtheothersfollow CooperationandCartels Ifthefirmsinanoligopolycooperate theymayearnmoreprofitsthaniftheyactindependently Collusion whichleadstosecretcooperativeagreements isillegalintheU S althoughitislegalandacceptableinmanyothercountries Price LeadershipCartelsmayforminwhichfirmssimplydowhateverasingleleadingfirmintheindustrydoes Thisavoidsstrategicbehaviorandrequiresnoillegalcollusion WhyArePricesSticky Informalcollusionisanimportantreasonwhypricesaresticky Anotheristhekinkeddemandcurve Cartels Acartelisanorganizationofindependentfirmswhosepurposeistocontrolandlimitproductionandmaintainorincreasepricesandprofits Likecollusion cartelsareillegalintheUnitedStates Conditionsnecessaryforacarteltobestable maintainable Therearefewfirmsintheindustry Therearesignificantbarrierstoentry Anidenticalproductisproduced Therearefewopportunitiestokeepactionssecret Therearenolegalbarrierstosharingagreements OPECasanExampleofaCartel OPEC OrganizationofPetroleumExportingCountries Attemptstosetpriceshighenoughtoearnmembercountriessignificantprofits butnotsohighastoencouragedramaticincreasesinoilexplorationorthepursuitofalternativeenergysources Controlspricesbysettingproductionquotasformembercountries Suchcartelsaredifficulttosustainbecausemembershavelargeincentivestocheat exceedingtheirquotas TheDiamondCartel In1870hugediamondminesinSouthAfricafloodedthegemmarketwithdiamonds InvestorsatthetimewantedtocontrolproductionandcreatedDeBeersConsolidatedMines Ltd whichquicklytookcontrolofallaspectsoftheworlddiamondtrade TheDiamondCartel headedbyDeBeers hasbeenextremelysuccessful Whileothercommodities prices suchasgoldandsil