OligopolyChapter16-2當(dāng)前1頁，總共41頁。ModelsofOligopolyBehaviorNosinglegeneralmodelofoligopolybehaviorexists.當(dāng)前2頁，總共41頁。OligopolyAnoligopolyisamarketstructurecharacterizedby:FewfirmsEitherstandardizedordifferentiatedproductsDifficultentry

當(dāng)前3頁，總共41頁。InterdependenceAkeycharacteristicofoligopoliesisthateachfirmcanaffectthemarket,makingeachfirm’schoicesdependentonthechoicesoftheotherfirms.Theyareinterdependent.當(dāng)前4頁，總共41頁。CharacteristicsOligopolyOligopoliesaremadeupofasmallnumberofmutuallyinterdependentfirms.Eachfirmmusttakeintoaccounttheexpectedreactionofotherfirms.當(dāng)前5頁，總共41頁。InterdependenceTheimportanceofinterdependenceisthatitleadstostrategicbehavior.

StrategicbehavioristhebehaviorthatoccurswhenwhatisbestforAdependsuponwhatBdoes,andwhatisbestforBdependsuponwhatAdoes.

Oligopolisticbehaviorincludesbothruthlesscompetitionandcooperation.當(dāng)前6頁，總共41頁。GameTheoryStrategicbehaviorhasbeenanalyzedusingthemathematicaltechniquesofgametheory.

Gametheoryprovidesadescriptionofoligopolisticbehaviorasaseriesofstrategicmovesandcountermoves.當(dāng)前7頁，總共41頁。CharacteristicsofOligopolyOligopoliesaremadeupofasmallnumberoffirmsinanindustryOligopolisticfirmsaremutuallyinterdependentInanydecisionafirmmakes,itmusttakeintoaccounttheexpectedreactionofotherfirmsOligopoliescanbecollusiveornoncollusiveFirmsmayengageinstrategicdecisionmaking

whereeachfirmtakesexplicitaccountofarival’sexpectedresponsetoadecisionitismaking16-8當(dāng)前8頁，總共41頁。ModelsofOligopolyBehaviorThereisnosinglemodelofoligopolybehaviorThecartelmodel

iswhenacombinationoffirmsactsasifitwereasinglefirmandamonopolypriceissetAnoligopolymodelcantaketwoextremes:Thecontestablemarketmodel

isamodelofoligopolieswherebarrierstoentryandexit,notmarketstructure,determinepriceandoutputdecisionsandacompetitivepriceissetOthermodelsofoligopoliesgivepriceresultsbetweenthetwoextremes16-9當(dāng)前9頁，總共41頁。TheCartelModelAcartelmodelofoligopolyisamodelthatassumesthatoligopoliesactasiftheywereamonopolyandsetapricetomaximizeprofitOutputquotasareassignedtoindividualmemberfirmssothattotaloutputisconsistentwithjointprofitmaximizationIfoligopoliescanlimittheentryofotherfirms,theycanincreaseprofits16-10當(dāng)前10頁，總共41頁。ImplicitPriceCollusionExplicit(formal)collusionisillegalintheU.S.whileimplicit(informal)collusionispermittedImplicitpricecollusion

existswhenmultiplefirmsmakethesamepricingdecisionseventhoughtheyhavenotconsultedwithoneanotherSometimesthelargestormostdominantfirmtakestheleadinsettingpricesandtheothersfollow16-11當(dāng)前11頁，總共41頁。WhyArePricesSticky?Onecharacteristicofinformalcollusivebehavioristhatpricestendtobesticky–theydon’tchangefrequentlyInformalcollusionisanimportantreasonwhypricesarestickyAnotheristhekinkeddemandcurveIfafirmincreasesprice,otherswon’tgoalong,sodemandisveryelasticforpriceincreasesIfafirmlowersprice,otherfirmsmatchthedecrease,sodemandisinelasticforpricedecreases16-12當(dāng)前12頁，總共41頁。TheKinkedDemandCurveGraphAgapintheMRcurveexistsAlargeshiftinmarginalcostisrequiredbeforefirmswillchangetheirpriceQPQMC1DMRPIfPincreases,otherswon’tgoalong,soDiselasticIfPdecreases,otherfirmsmatchthedecrease,soDisinelasticMC2Gap16-13當(dāng)前13頁，總共41頁。TheContestableMarketModelThecontestablemarketmodelisamodelofoligopolieswherebarrierstoentryandexit,notmarketstructure,determinepriceandoutputdecisionsandacompetitivepriceissetEveniftheindustrycontainsonlyonefirm,itwillsetacompetitivepriceiftherearenobarrierstoentryMuchofwhathappensinoligopolypricingisdependentonthespecificlegalstructurewithinwhichfirmsinteract16-14當(dāng)前14頁，總共41頁。ComparingContestableMarketandCartelModelsThecartelmodelisappropriateforoligopoliststhatcollude,setamonopolyprice,andpreventmarketentryThecontestablemarketmodeldescribesoligopoliesthatsetacompetitivepriceandhavenobarrierstoentryOligopolymarketsliebetweenthesetwoextremesBothmodelsusestrategicpricingdecisions

wherefirmssettheirpricebasedontheexpectedreactionsofotherfirms16-15當(dāng)前15頁，總共41頁。NewEntryasaLimitonthe

CartelizationStrategyandPriceWarsPricewarsaretheresultofstrategicpricingdecisionsgonewildApredatorypricingstrategy

involvestemporarilypushingthepricedowninordertodriveacompetitoroutofbusinessThethreatofoutsidecompetitionlimitsoligopoliesfromactingasacartelThethreatwillbemoreeffectiveiftheoutsidecompetitorismuchlargerthanthefirmsintheoligopoly16-16當(dāng)前16頁，總共41頁。WhyArePricesSticky?Whenthereisakinkinthedemandcurve,therehastobeagapinthemarginalrevenuecurve.Thekinkeddemandcurveisnotatheoryofoligopolybutatheoryofstickyprices.當(dāng)前17頁，總共41頁。D2TheKinkedDemandCurveD1MR2MR1PriceQuantity0QPabcdMC0MC1當(dāng)前18頁，總共41頁。TheKinkedDemandCurve當(dāng)前19頁，總共41頁。GameTheoryandStrategicDecisionMakingTheprisoner’sdilemmaisawell-knowngamethatdemonstratesthedifficultyofcooperativebehaviorincertaincircumstances.當(dāng)前20頁，總共41頁。GameTheoryandStrategicDecisionMakingIntheprisoner’sdilemma,wheremutualtrustgetseachoneoutofthedilemma,confessingistherationalchoice.當(dāng)前21頁，總共41頁。Prisoner’sDilemmaandaDuopolyExampleTheprisonersdilemmahasitssimplestapplicationwhentheoligopolyconsistsofonlytwofirms—aduopoly.當(dāng)前22頁，總共41頁。Prisoner’sDilemmaandaDuopolyExampleByanalyzingthestrategiesofbothfirmsunderallsituations,allpossibilitiesareplacedinapayoff

matrix.A

payoffmatrixisaboxthatcontainstheoutcomesofastrategicgameundervariouscircumstances.當(dāng)前23頁，總共41頁。FirmandIndustryDuopolyCooperativeEquilibriumPricePrice575$8007006005004003002001000(a)Firm'scostcurves12345678Quantity(inthousands)MCATC$80070060050040030020010001234567891011MonopolistsolutionMRDCompetitivesolutionMC(b)Industry:CompetitiveandmonopolistsolutionQuantity(inthousands)McGraw-Hill/Irwin?2004TheMcGraw-HillCompanies,Inc.,AllRightsReserved.當(dāng)前24頁，總共41頁。FirmandIndustryDuopolyEquilibriumWhenOneFirmCheatsPricePricePrice$8007006005004003002001000$8007006005004003002001000$900800700600500400300200100055055055012345671234567AMCATCQuantity(inthousands)(a)Noncheatingfirm’slossAMCATCQuantity(inthousands)(b)Cheatingfirm’sprofitABC12345678Quantity(inthousands)(c)CheatingsolutionNon-cheatingfirm’soutputCheatingfirm’soutputMcGraw-Hill/Irwin?2004TheMcGraw-HillCompanies,Inc.,AllRightsReserved.當(dāng)前25頁，總共41頁。DuopolyandaPayoffMatrixTheduopolyisavariationoftheprisoner'sdilemmagame.Theresultscanbepresentedinapayoffmatrixthatcapturestheessenceoftheprisoner'sdilemma.當(dāng)前26頁，總共41頁。BCheats

BDoesnotcheatADoesnotcheatACheatsB+$200,000B0A0A+$200,000B$75,000A$75,000A–$75,000B–$75,000ThePayoffMatrixofStrategicPricingDuopoly當(dāng)前27頁，總共41頁。DominantStrategyInanoligopoly,firmstrytoachieveadominant

strategy—astrategythatproducesbetterresultsnomatterwhatstrategyotherfirmsfollow.

Theinterdependenceofoligopoliesdecisionscanoftenleadtotheprisoner’sdilemma.當(dāng)前28頁，總共41頁。Prisoner’sDilemma當(dāng)前29頁，總共41頁。ImplicitPriceCollusionFormalcollusionisillegalintheU.S.whileinformalcollusionispermitted.Implicitpricecollusionexistswhenmultiplefirmsmakethesamepricingdecisionseventhoughtheyhavenotconsultedwithoneanother.當(dāng)前30頁，總共41頁。ImplicitPriceCollusionSometimesthelargestormostdominantfirmtakestheleadinsettingpricesandtheothersfollow.當(dāng)前31頁，總共41頁。CooperationandCartelsIfthefirmsinanoligopolycooperate,theymayearnmoreprofitsthaniftheyactindependently.

Collusion,whichleadstosecretcooperativeagreements,isillegalintheU.S.,althoughitislegalandacceptableinmanyothercountries.

Price-LeadershipCartelsmayforminwhichfirmssimplydowhateverasingleleadingfirmintheindustrydoes.Thisavoidsstrategicbehaviorandrequiresnoillegalcollusion.ImplicitPriceCollusion當(dāng)前32頁，總共41頁。WhyArePricesSticky?Informalcollusionisanimportantreasonwhypricesaresticky.Anotheristhekinkeddemandcurve.當(dāng)前33頁，總共41頁。CartelsAcartelisanorganizationofindependentfirmswhosepurposeistocontrolandlimitproductionandmaintainorincreasepricesandprofits.

Likecollusion,cartelsareillegalintheUnitedStates.

當(dāng)前34頁，總共41頁。Conditionsnecessaryforacarteltobestable(maintainable):

Therearefewfirmsintheindustry.Therearesignificantbarrierstoentry.Anidenticalproductisproduced.Therearefewopportunitiestokeepactionssecret.Therearenolegalbarrierstosharingagreements.當(dāng)前35頁，總共41頁。OPECasanExampleofaCartelOPEC:OrganizationofPetroleumExportingCountries.

Attemptstosetpriceshighenoughtoearnmembercountriessignificantprofits,butnotsohighastoencouragedramaticincreasesinoilexplorationorthepursuitofalternativeenergysources.

Controlspricesbysettingproductionquotasfor

membercountries.

Suchcartelsaredifficulttosustainbecausemembershavelargeincentivestocheat,exceedingtheirquotas.當(dāng)前36頁，總共41頁。TheDiamondCartelIn1870hugediamondminesinSouthAfricafloodedthegemmarketwithdiamonds.InvestorsatthetimewantedtocontrolproductionandcreatedDeBeersConsolidatedMines,Ltd.,whichquicklytookcontrolofallaspectsoftheworlddiamondtrade.TheDiamondCartel,head