OligopolyChapter16-2現在是1頁\一共有41頁\編輯于星期一ModelsofOligopolyBehaviorNosinglegeneralmodelofoligopolybehaviorexists.現在是2頁\一共有41頁\編輯于星期一OligopolyAnoligopolyisamarketstructurecharacterizedby:FewfirmsEitherstandardizedordifferentiatedproductsDifficultentry

現在是3頁\一共有41頁\編輯于星期一InterdependenceAkeycharacteristicofoligopoliesisthateachfirmcanaffectthemarket,makingeachfirm’schoicesdependentonthechoicesoftheotherfirms.Theyareinterdependent.現在是4頁\一共有41頁\編輯于星期一CharacteristicsOligopolyOligopoliesaremadeupofasmallnumberofmutuallyinterdependentfirms.Eachfirmmusttakeintoaccounttheexpectedreactionofotherfirms.現在是5頁\一共有41頁\編輯于星期一InterdependenceTheimportanceofinterdependenceisthatitleadstostrategicbehavior.

StrategicbehavioristhebehaviorthatoccurswhenwhatisbestforAdependsuponwhatBdoes,andwhatisbestforBdependsuponwhatAdoes.

Oligopolisticbehaviorincludesbothruthlesscompetitionandcooperation.現在是6頁\一共有41頁\編輯于星期一GameTheoryStrategicbehaviorhasbeenanalyzedusingthemathematicaltechniquesofgametheory.

Gametheoryprovidesadescriptionofoligopolisticbehaviorasaseriesofstrategicmovesandcountermoves.現在是7頁\一共有41頁\編輯于星期一CharacteristicsofOligopolyOligopoliesaremadeupofasmallnumberoffirmsinanindustryOligopolisticfirmsaremutuallyinterdependentInanydecisionafirmmakes,itmusttakeintoaccounttheexpectedreactionofotherfirmsOligopoliescanbecollusiveornoncollusiveFirmsmayengageinstrategicdecisionmaking

whereeachfirmtakesexplicitaccountofarival’sexpectedresponsetoadecisionitismaking16-8現在是8頁\一共有41頁\編輯于星期一ModelsofOligopolyBehaviorThereisnosinglemodelofoligopolybehaviorThecartelmodel

iswhenacombinationoffirmsactsasifitwereasinglefirmandamonopolypriceissetAnoligopolymodelcantaketwoextremes:Thecontestablemarketmodel

isamodelofoligopolieswherebarrierstoentryandexit,notmarketstructure,determinepriceandoutputdecisionsandacompetitivepriceissetOthermodelsofoligopoliesgivepriceresultsbetweenthetwoextremes16-9現在是9頁\一共有41頁\編輯于星期一TheCartelModelAcartelmodelofoligopolyisamodelthatassumesthatoligopoliesactasiftheywereamonopolyandsetapricetomaximizeprofitOutputquotasareassignedtoindividualmemberfirmssothattotaloutputisconsistentwithjointprofitmaximizationIfoligopoliescanlimittheentryofotherfirms,theycanincreaseprofits16-10現在是10頁\一共有41頁\編輯于星期一ImplicitPriceCollusionExplicit(formal)collusionisillegalintheU.S.whileimplicit(informal)collusionispermittedImplicitpricecollusion

existswhenmultiplefirmsmakethesamepricingdecisionseventhoughtheyhavenotconsultedwithoneanotherSometimesthelargestormostdominantfirmtakestheleadinsettingpricesandtheothersfollow16-11現在是11頁\一共有41頁\編輯于星期一WhyArePricesSticky?Onecharacteristicofinformalcollusivebehavioristhatpricestendtobesticky–theydon’tchangefrequentlyInformalcollusionisanimportantreasonwhypricesarestickyAnotheristhekinkeddemandcurveIfafirmincreasesprice,otherswon’tgoalong,sodemandisveryelasticforpriceincreasesIfafirmlowersprice,otherfirmsmatchthedecrease,sodemandisinelasticforpricedecreases16-12現在是12頁\一共有41頁\編輯于星期一TheKinkedDemandCurveGraphAgapintheMRcurveexistsAlargeshiftinmarginalcostisrequiredbeforefirmswillchangetheirpriceQPQMC1DMRPIfPincreases,otherswon’tgoalong,soDiselasticIfPdecreases,otherfirmsmatchthedecrease,soDisinelasticMC2Gap16-13現在是13頁\一共有41頁\編輯于星期一TheContestableMarketModelThecontestablemarketmodelisamodelofoligopolieswherebarrierstoentryandexit,notmarketstructure,determinepriceandoutputdecisionsandacompetitivepriceissetEveniftheindustrycontainsonlyonefirm,itwillsetacompetitivepriceiftherearenobarrierstoentryMuchofwhathappensinoligopolypricingisdependentonthespecificlegalstructurewithinwhichfirmsinteract16-14現在是14頁\一共有41頁\編輯于星期一ComparingContestableMarketandCartelModelsThecartelmodelisappropriateforoligopoliststhatcollude,setamonopolyprice,andpreventmarketentryThecontestablemarketmodeldescribesoligopoliesthatsetacompetitivepriceandhavenobarrierstoentryOligopolymarketsliebetweenthesetwoextremesBothmodelsusestrategicpricingdecisions

wherefirmssettheirpricebasedontheexpectedreactionsofotherfirms16-15現在是15頁\一共有41頁\編輯于星期一NewEntryasaLimitonthe

CartelizationStrategyandPriceWarsPricewarsaretheresultofstrategicpricingdecisionsgonewildApredatorypricingstrategy

involvestemporarilypushingthepricedowninordertodriveacompetitoroutofbusinessThethreatofoutsidecompetitionlimitsoligopoliesfromactingasacartelThethreatwillbemoreeffectiveiftheoutsidecompetitorismuchlargerthanthefirmsintheoligopoly16-16現在是16頁\一共有41頁\編輯于星期一WhyArePricesSticky?Whenthereisakinkinthedemandcurve,therehastobeagapinthemarginalrevenuecurve.Thekinkeddemandcurveisnotatheoryofoligopolybutatheoryofstickyprices.現在是17頁\一共有41頁\編輯于星期一D2TheKinkedDemandCurveD1MR2MR1PriceQuantity0QPabcdMC0MC1現在是18頁\一共有41頁\編輯于星期一TheKinkedDemandCurve現在是19頁\一共有41頁\編輯于星期一GameTheoryandStrategicDecisionMakingTheprisoner’sdilemmaisawell-knowngamethatdemonstratesthedifficultyofcooperativebehaviorincertaincircumstances.現在是20頁\一共有41頁\編輯于星期一GameTheoryandStrategicDecisionMakingIntheprisoner’sdilemma,wheremutualtrustgetseachoneoutofthedilemma,confessingistherationalchoice.現在是21頁\一共有41頁\編輯于星期一Prisoner’sDilemmaandaDuopolyExampleTheprisonersdilemmahasitssimplestapplicationwhentheoligopolyconsistsofonlytwofirms—aduopoly.現在是22頁\一共有41頁\編輯于星期一Prisoner’sDilemmaandaDuopolyExampleByanalyzingthestrategiesofbothfirmsunderallsituations,allpossibilitiesareplacedinapayoff

matrix.A

payoffmatrixisaboxthatcontainstheoutcomesofastrategicgameundervariouscircumstances.現在是23頁\一共有41頁\編輯于星期一FirmandIndustryDuopolyCooperativeEquilibriumPricePrice575$8007006005004003002001000(a)Firm'scostcurves12345678Quantity(inthousands)MCATC$80070060050040030020010001234567891011MonopolistsolutionMRDCompetitivesolutionMC(b)Industry:CompetitiveandmonopolistsolutionQuantity(inthousands)McGraw-Hill/Irwin?2004TheMcGraw-HillCompanies,Inc.,AllRightsReserved.現在是24頁\一共有41頁\編輯于星期一FirmandIndustryDuopolyEquilibriumWhenOneFirmCheatsPricePricePrice$8007006005004003002001000$8007006005004003002001000$900800700600500400300200100055055055012345671234567AMCATCQuantity(inthousands)(a)Noncheatingfirm’slossAMCATCQuantity(inthousands)(b)Cheatingfirm’sprofitABC12345678Quantity(inthousands)(c)CheatingsolutionNon-cheatingfirm’soutputCheatingfirm’soutputMcGraw-Hill/Irwin?2004TheMcGraw-HillCompanies,Inc.,AllRightsReserved.現在是25頁\一共有41頁\編輯于星期一DuopolyandaPayoffMatrixTheduopolyisavariationoftheprisoner'sdilemmagame.Theresultscanbepresentedinapayoffmatrixthatcapturestheessenceoftheprisoner'sdilemma.現在是26頁\一共有41頁\編輯于星期一BCheats

BDoesnotcheatADoesnotcheatACheatsB+$200,000B0A0A+$200,000B$75,000A$75,000A–$75,000B–$75,000ThePayoffMatrixofStrategicPricingDuopoly現在是27頁\一共有41頁\編輯于星期一DominantStrategyInanoligopoly,firmstrytoachieveadominant

strategy—astrategythatproducesbetterresultsnomatterwhatstrategyotherfirmsfollow.

Theinterdependenceofoligopoliesdecisionscanoftenleadtotheprisoner’sdilemma.現在是28頁\一共有41頁\編輯于星期一Prisoner’sDilemma現在是29頁\一共有41頁\編輯于星期一ImplicitPriceCollusionFormalcollusionisillegalintheU.S.whileinformalcollusionispermitted.Implicitpricecollusionexistswhenmultiplefirmsmakethesamepricingdecisionseventhoughtheyhavenotconsultedwithoneanother.現在是30頁\一共有41頁\編輯于星期一ImplicitPriceCollusionSometimesthelargestormostdominantfirmtakestheleadinsettingpricesandtheothersfollow.現在是31頁\一共有41頁\編輯于星期一CooperationandCartelsIfthefirmsinanoligopolycooperate,theymayearnmoreprofitsthaniftheyactindependently.

Collusion,whichleadstosecretcooperativeagreements,isillegalintheU.S.,althoughitislegalandacceptableinmanyothercountries.

Price-LeadershipCartelsmayforminwhichfirmssimplydowhateverasingleleadingfirmintheindustrydoes.Thisavoidsstrategicbehaviorandrequiresnoillegalcollusion.ImplicitPriceCollusion現在是32頁\一共有41頁\編輯于星期一WhyArePricesSticky?Informalcollusionisanimportantreasonwhypricesaresticky.Anotheristhekinkeddemandcurve.現在是33頁\一共有41頁\編輯于星期一CartelsAcartelisanorganizationofindependentfirmswhosepurposeistocontrolandlimitproductionandmaintainorincreasepricesandprofits.

Likecollusion,cartelsareillegalintheUnitedStates.

現在是34頁\一共有41頁\編輯于星期一Conditionsnecessaryforacarteltobestable(maintainable):

Therearefewfirmsintheindustry.Therearesignificantbarrierstoentry.Anidenticalproductisproduced.Therearefewopportunitiestokeepactionssecret.Therearenolegalbarrierstosharingagreements.現在是35頁\一共有41頁\編輯于星期一OPECasanExampleofaCartelOPEC:OrganizationofPetroleumExportingCountries.

Attemptstosetpriceshighenoughtoearnmembercountriessignificantprofits,butnotsohighastoencouragedramaticincreasesinoilexplorationorthepursuitofalternativeenergysources.

Controlspricesbysettingproductionquotasfor

membercountries.

Suchcartelsaredifficulttosustainbecausemembershavelargeincentivestocheat,exceedingtheirquotas.現在是36頁\一共有41頁\編輯于星期一TheDiamondCartelIn1870hugediamondminesinSouthAfricafloodedthegemmarketwithdiamonds.InvestorsatthetimewantedtocontrolproductionandcreatedDeBeersConsolidatedMines,Ltd.,whichquicklytookcontrolofallaspectsoftheworlddiamondtrade.TheDiamondCartel,headedbyD