《競(jìng)爭(zhēng)策略》課件

企業(yè)管理中的競(jìng)爭(zhēng)問題董志勇博士副教授中國(guó)人民大學(xué)經(jīng)濟(jì)學(xué)院職業(yè)經(jīng)理人資格－－中國(guó)最具價(jià)值的三大證書之一〖CCMC與企業(yè)管理〗

1企業(yè)管理中的競(jìng)爭(zhēng)問題董志勇博士副教授職業(yè)經(jīng)理人資格－－中個(gè)人簡(jiǎn)介----中國(guó)人民大學(xué)經(jīng)濟(jì)學(xué)院院長(zhǎng)助理副教授經(jīng)濟(jì)學(xué)博士----2008年北京奧運(yùn)會(huì)特許商品調(diào)查委員會(huì)首席專家----2008年北京奧運(yùn)會(huì)旅游紀(jì)念品調(diào)查研究首席專家----歐美同學(xué)會(huì)會(huì)員（1998年）----中國(guó)寶雞外國(guó)語學(xué)院客座教授(1999年)----新加坡華夏學(xué)院學(xué)術(shù)委員會(huì)委員(2001年)----歐洲維多利亞大學(xué)客座教授（2002年）----亞洲發(fā)展銀行青年組專家(YoungEconomistofADB)（2002年）----清華大學(xué)繼續(xù)教育學(xué)院客座教授（2003年）----吉林電力高級(jí)經(jīng)濟(jì)顧問（2002年）----吉林白城市人民政府經(jīng)濟(jì)顧問（2003年）----國(guó)聯(lián)股份高級(jí)顧問（2003年）----中國(guó)人民大學(xué)僑聯(lián)副主席（2004年）----中國(guó)井岡山干部學(xué)院兼職教授（2005年）2個(gè)人簡(jiǎn)介2博弈論和策略行為GameTheory&StrategicBehaviors3博弈論和策略行為3LecturePlan/本講計(jì)劃GameTheoryStrategy&PayoffMatrixDominant&DominatedStrategiesNashEquilibriumMaximinStrategy&MixedStrategyStrategicBehavior4LecturePlan/本講計(jì)劃GameTheory4ElementsofaGameGamehasthefollowingelements:Players:whoisinvolved?Rules:whomoveswhen?Whatdotheyknowwhentheymove?Whatcantheydo?Outcomes:foreachpossiblesetofactionsbythelayers,whichistheoutcomeofthegamePayoffs:whataretheplayers’preferencesoverthepossibleoutcome?5ElementsofaGameGamehastheStrategy&Payoffs博弈論把人間一切競(jìng)爭(zhēng)活動(dòng)看成是玩策略游戲。這種策略游戲是在一定的游戲規(guī)則之下進(jìn)行它的兩個(gè)最基本的概念是策略與支付矩陣一種策略(Strategy)表示游戲參與者的一套運(yùn)作計(jì)劃和手段。如“降價(jià)15%”就是一種策略收益矩陣(Payoffmatrix)是表示游戲參與者在各種不同策略下的利潤(rùn)額的一套支付表格寡頭壟斷，尤其是雙寡頭壟斷競(jìng)爭(zhēng)，特別適合使用博弈論研究6Strategy&Payoffs博弈論把人間一切競(jìng)爭(zhēng)活動(dòng)Strategy&PayoffsPrisoner’sDilemma(囚犯兩難)兩個(gè)嫌犯被捕并受到指控，但除非至少一人招供犯罪，警方并無充分證據(jù)將其按罪判刑警方將他們分開審訊（不能溝通），并對(duì)他們說明不同行動(dòng)帶來的后果。如果二人都不坦白，只能判簡(jiǎn)單刑事罪，坐牢1個(gè)月如果二人都坦白，兩人都會(huì)定罪，判刑六個(gè)月；如果其中一個(gè)坦白，另一個(gè)不坦白；那么坦白者馬上釋放（從寬）、不坦白者將會(huì)判刑九個(gè)月。請(qǐng)問兩個(gè)嫌犯該怎么辦？7Strategy&PayoffsPrisoner’sDStrategy&PayoffsPrisoner’sDilemma(囚犯兩難)策略(Strategy):“沉默”&“招認(rèn)”收益矩陣(PayoffMatrix)如下：囚犯2沉默招認(rèn)囚犯1沉默-1，-1-9，0招認(rèn)0，-9-6，-68Strategy&PayoffsPrisoner’sDStrategy&PayoffsPrisoner’sDilemma(囚犯兩難)囚犯兩難的問題在現(xiàn)實(shí)中常常出現(xiàn)。比如兩家企業(yè)的價(jià)格戰(zhàn)。企業(yè)B遵守協(xié)議違約降價(jià)企業(yè)A遵守協(xié)議100，10030，130違約降價(jià)130，3070，709Strategy&PayoffsPrisoner’sDStrategy&Payoffs性別戰(zhàn)博弈(TheBattleofSex)一男一女試圖安排一個(gè)晚上的娛樂內(nèi)容選擇（策略）：“歌劇”、“拳擊”；不過男女有別收益矩陣(PayoffMatrix)如下：男(TheMan)歌劇拳擊女(TheLady)歌劇2，10，0拳擊0，01，210Strategy&Payoffs性別戰(zhàn)博弈(TheB1111Strategy&PayoffsOtherExamplesCoordinationgamesSmithandJonesaretryingtodecidewhethertodesignthecomputerstheyselltouselargeorsmallfloppydisksBothplayerswillsellmorecomputersiftheirdiskdrivesarecompatible.Strategies:“Large”or“Small”Payoffsareasfollows.12Strategy&PayoffsOtherExamplStrategy&PayoffsOtherExamplesCoordinationgames:payoffmatrixJonesLargeSmallSmithLarge2,2-1,-1Small-1，-11,113Strategy&PayoffsOtherExamplDominantStrategies(支配策略)Wesayaplayerhasadominantstrategyifitisthestrictlybestresponsetoanystrategiestheotherplayersmightpick.Intheanalysisofanygame,thefirststepistodetermineifanyplayerhasadominantstrategy.Ifsuchastrategyexists,thentheoutcomeofthegameshouldbeeasilydetermined,sincetheplayerwillusethedominantstrategyandotherplayerswillsubsequentlyadopttheirbestresponses.Examples:DoesthePrisoner’sDilemmahaveanydominantstrategy?HowabouttheCoordinationGame?14DominantStrategies(支配策略)WesDominatedStrategies(被支配策略)Adominatedstrategyisanalternativethatyieldsalowerpayoffthansomeotherstrategy,nomatterwhattheotherplayersinthegamedo.Arationalplayerwillneveruseadominatedstrategyintheactualactionofgameplaying.Henceitcanbeeliminated.Itisclearthatiftheexistenceofadominantstrategyimpliesthatallotherchoicesareinfactthedominatedstrategies.Butitispossiblethattherearedominatedstrategies,whilethereisnodominantstrategy15DominatedStrategies(被支配策略)AApplication:IterativeEliminationsExample16Application:IterativeEliminaNashEquilibrium(納什均衡)Eventhoughusingadominantstrategyoradominatedstrategyisapowerfulsimplewayof“solving”agame,thiskindofgameisusuallyanexception,insteadofanorm.Wemusthaveagenericmethodoffindingthesolution(s)ofagame.SolutionConceptsNashEquilibriumistheveryfirstsolutionconceptfornon-cooperativegames.17NashEquilibrium(納什均衡)EventhNashEquilibrium(納什均衡)EssenceofNashEquilibriumANashEquilibriumisdefinedasasetofstrategiessuchthatnonoftheparticipantsinthegamecanimprovetheirpayoff,giventhestrategiesoftheotherparticipants.NoonehasastrictlyincentivetodeviatefromthestrategiesinaNashEquilibrium.18NashEquilibrium(納什均衡)EssenceNashEquilibrium(納什均衡)ExampleConsiderthefollowinggame.Isthereanydominantordominatedstrategy?19NashEquilibrium(納什均衡)ExampleNashEquilibrium(納什均衡)ProblemofNashEquilibrium:Multiplesolutions!Examples:BattleofSex

CoordinationGame男(TheMan)歌劇拳擊女(TheLady)歌劇2，10，0拳擊0，01，2JonesLargeSmallSmithLarge2,2-1,-1Small-1，-11,120NashEquilibrium(納什均衡)ProblemNashEquilibrium(納什均衡)ProblemofNashEquilibrium:Insensitivetoextremepayoffs(risks)Example:DangerousCoordinationGameJonesLargeSmallSmithLarge2,2-1000,-1Small-1，-11,1InPractice,itisalmostsurethatSmithwantsto“playsafe”andnevertry“l(fā)arge”!21NashEquilibrium(納什均衡)ProblemNashEquilibrium(納什均衡)ProblemofNashEquilibrium:Non-existenceofpurestrategyNashEquilibriumExample:MatchthePenniesNodominantstrategy,nodominatedstrategy&nopurestrategyNashequilibriumaswell!BHeadTailAHead1,-1-1,1Tail-1，11,-122NashEquilibrium(納什均衡)ProblemNashEquilibrium(納什均衡)MixedStrategies（混合策略）Amixedstrategyisaprofilethatspecifiestheprobabilityofeachpurestrategythatistobeplayed.NashTheorem:Foranygamewithfinitenumberofpurestrategies,therealwaysexistsaNashEquilibriuminmixedstrategyform.23NashEquilibrium(納什均衡)MixedSNashEquilibrium(納什均衡)MixedStrategies（混合策略）:ExamplesCoordinationGameJonesplays(Large,Small)accordingto(p,1-p)Smith’sexpectedpayoffsare:“Large”:2p+(-1)(1-p)=US(L|(p,1-p))“Small”:(-1)p+1(1-p)=US(S|(p,1-p))Smithshouldbe“indifferent”betweenthetwochoicesUS(L|(p,1-p))=US(S|(p,1-p))p=2/5HenceJones’optimalmixedstrategymustbe(0.4,0.6)Exercise:findtheoptimalmixedstrategyforSmith.MatchingthePenniesFindtheNashequilibriuminmixedstrategies24NashEquilibrium(納什均衡)MixedS25252626NashEquilibrium(納什均衡)NashEquilibrium不一定有效率TheCentipedeGame(蜈蚣蟲游戲):Inthisfinitegameofperfectinformation,therearetwoplayers,1and2.Theplayerseachstartwith1dollarinfrontofthem.Theyalternatesaying‘stop’or‘continue’,startingwithplayer1.Whenaplayersays‘continue’,1dollaristakenbyarefereefromherpileand2dollarsareputinheropponent’spile.Assoonaseitherplayersays‘stop’,plyisterminated,andeachplayerreceivesthemoneycurrentlyinherpile.Alternatively,playstopsifbothplayers’pilesreach100dollars.27NashEquilibrium(納什均衡)NashEqPlayer1Player2Player1Player2Player1Player2SCCCCCCSSSSS11032297100999998101100,10028Player1Player2Player1PlayerMaxminStrategies(最大最小策略)Wheneachplayerinthegamewillselecttheoptionthatmaximizestheminimumpossibleprofit(orotherdesirableoutcome),wesaythatthedecisionruleisamaxminstrategy.Thismayhappeninsituationswhenthemarketishighlycompetitiveanddecisionmakersareriskaverse.Sothisisausefulcaseformanagerialdecisionmaking.29MaxminStrategies(最大最小策略)When

3030迄今為止，對(duì)市場(chǎng)結(jié)構(gòu)分析都以假定管理決策的中心是謀求最大利益。但是在如壟斷寡頭那樣競(jìng)爭(zhēng)十分激烈的場(chǎng)合，決策者可能采取一種風(fēng)險(xiǎn)厭惡政策，即確保在可能的最壞結(jié)果中得到最好的結(jié)果。也就是每個(gè)博弈者將在可能最少的利潤(rùn)方案中選擇利潤(rùn)最大的方案。31迄今為止，對(duì)市場(chǎng)結(jié)構(gòu)分析都以假定管理決策的中心是謀求最大利益（續(xù)）Nash均衡為（3，6）和（6，3）企業(yè)1最小32企業(yè)2最小32結(jié)果：雙方都沒有新產(chǎn)品推出在這個(gè)例子中，Nash不是小中取大解！32（續(xù)）企業(yè)1最小企業(yè)2最小3MaxminStrategies(最大最小策略)Anotherexample:33MaxminStrategies(最大最小策略)AnotSequentialGame(順序性博弈)順序性博弈：先下弈的優(yōu)勢(shì)(First-moverAdvantage)迄今為止，我們都隱含假定雙方下弈者都是同時(shí)實(shí)施。在順序(Sequentialgame)中，就是有先有后了。進(jìn)入新的市場(chǎng)就是一個(gè)順序博弈的例子。34SequentialGame(順序性博弈)順序性博弈：先3535363637373838StrategicBehavior:BarriersofEntryFourtraditionalbarrierstoentry(passive)Economiesofscale,productdifferentiation,controloverscareresources,andlegalfactorsMarketEntryDecision(EntryGame)(aggressive)Presentvs.FutureProfits:Entry-LimitingPricingMainideas:Motivation:short-runMonopolypricingpracticeearns“toomuchprofits”,henceattractnewentrantsthatwilleatupthemarketshareanddrivedownthepricesinthelongrunEntry-LimitPricing:needtosetapricebelowtheshort-runmonopolyprice(Fig11-1,p.293)Figure11-2:profitstreams39StrategicBehavior:BarriersoStrategicBehavior:BarriersofEntryStigler’sOpenOligopolyModelObjective:maximizethepresentvalueofprofitInsomecases,thismaybeachievedbysettingapricedesignedtodeterentryOptimalstrategydependsonthediscountratesusedbythemanagerstodeterminethepresentvalueofprofitAComparisonEntry-LimitingPricing:long-timehorizon&alowerdiscountrateOpenOligopolyModel:shortplanninghorizon&abiggerdiscountrate40StrategicBehavior:BarriersoStrategicBehavior:BarriersofEntryPriceRetaliation（價(jià)格報(bào)復(fù)）IncontrastwithLimitPricingthatkeepsthepricelowoveralongperiodoftime,anotherstrategicresponsetothethreatofentryistoretaliatebyreducingpriceswhenentryactuallydoesoccuroritappearsimminent.Whentheperceivedangerhasdiminished,pricescanbeincreasedtowhateverlevelmanagementviewsasappropriateformarketconditions.41StrategicBehavior:BarriersoStrategicBehavior:BarriersofEntryEstablishingCommitment:CapacityExpansion（擴(kuò)大生產(chǎn)能力）Astrategicresponsebyestablishedfirmstopreventthenewentrantsfromoccurringwouldbetoinvestinadditionalcapacity.Oncethisinvestmenthasbeenmade,itbecomesasunkcostandplacesexistingfirmsinapositiontoexpandtheirproductionasrelativelylowcost.Theexistenceofexcesscapacityprovidesastrongsignalthattheestablishedfirmscan(andprobablywill)reducepricesasastrategicresponsetoentryintheirmarket.42StrategicBehavior:BarriersoStrategicBehavior:BarriersofEntryPreemptiveAction:MarketSaturation(先發(fā)制人：使市場(chǎng)飽和)Oneentry-deterringstrategyfortheexistingfirmwouldbetodisperseitsproductionfacilities.Bytheexistingfirmspreadingitsplantsthroughoutthemarketarea(theanalysisofgeographicsaturationcanalsobeappliedtoproductcharacteristics)theopportunityforthenewentranttotakeadvantageofhightransportationcostsisgreatlyreduced.Example:BrandProliferationintheCerealIndustry43StrategicBehavior:Barrierso演講完畢，謝謝觀看！演講完畢，謝謝觀看！企業(yè)管理中的競(jìng)爭(zhēng)問題董志勇博士副教授中國(guó)人民大學(xué)經(jīng)濟(jì)學(xué)院職業(yè)經(jīng)理人資格－－中國(guó)最具價(jià)值的三大證書之一〖CCMC與企業(yè)管理〗

45企業(yè)管理中的競(jìng)爭(zhēng)問題董志勇博士副教授職業(yè)經(jīng)理人資格－－中個(gè)人簡(jiǎn)介----中國(guó)人民大學(xué)經(jīng)濟(jì)學(xué)院院長(zhǎng)助理副教授經(jīng)濟(jì)學(xué)博士----2008年北京奧運(yùn)會(huì)特許商品調(diào)查委員會(huì)首席專家----2008年北京奧運(yùn)會(huì)旅游紀(jì)念品調(diào)查研究首席專家----歐美同學(xué)會(huì)會(huì)員（1998年）----中國(guó)寶雞外國(guó)語學(xué)院客座教授(1999年)----新加坡華夏學(xué)院學(xué)術(shù)委員會(huì)委員(2001年)----歐洲維多利亞大學(xué)客座教授（2002年）----亞洲發(fā)展銀行青年組專家(YoungEconomistofADB)（2002年）----清華大學(xué)繼續(xù)教育學(xué)院客座教授（2003年）----吉林電力高級(jí)經(jīng)濟(jì)顧問（2002年）----吉林白城市人民政府經(jīng)濟(jì)顧問（2003年）----國(guó)聯(lián)股份高級(jí)顧問（2003年）----中國(guó)人民大學(xué)僑聯(lián)副主席（2004年）----中國(guó)井岡山干部學(xué)院兼職教授（2005年）46個(gè)人簡(jiǎn)介2博弈論和策略行為GameTheory&StrategicBehaviors47博弈論和策略行為3LecturePlan/本講計(jì)劃GameTheoryStrategy&PayoffMatrixDominant&DominatedStrategiesNashEquilibriumMaximinStrategy&MixedStrategyStrategicBehavior48LecturePlan/本講計(jì)劃GameTheory4ElementsofaGameGamehasthefollowingelements:Players:whoisinvolved?Rules:whomoveswhen?Whatdotheyknowwhentheymove?Whatcantheydo?Outcomes:foreachpossiblesetofactionsbythelayers,whichistheoutcomeofthegamePayoffs:whataretheplayers’preferencesoverthepossibleoutcome?49ElementsofaGameGamehastheStrategy&Payoffs博弈論把人間一切競(jìng)爭(zhēng)活動(dòng)看成是玩策略游戲。這種策略游戲是在一定的游戲規(guī)則之下進(jìn)行它的兩個(gè)最基本的概念是策略與支付矩陣一種策略(Strategy)表示游戲參與者的一套運(yùn)作計(jì)劃和手段。如“降價(jià)15%”就是一種策略收益矩陣(Payoffmatrix)是表示游戲參與者在各種不同策略下的利潤(rùn)額的一套支付表格寡頭壟斷，尤其是雙寡頭壟斷競(jìng)爭(zhēng)，特別適合使用博弈論研究50Strategy&Payoffs博弈論把人間一切競(jìng)爭(zhēng)活動(dòng)Strategy&PayoffsPrisoner’sDilemma(囚犯兩難)兩個(gè)嫌犯被捕并受到指控，但除非至少一人招供犯罪，警方并無充分證據(jù)將其按罪判刑警方將他們分開審訊（不能溝通），并對(duì)他們說明不同行動(dòng)帶來的后果。如果二人都不坦白，只能判簡(jiǎn)單刑事罪，坐牢1個(gè)月如果二人都坦白，兩人都會(huì)定罪，判刑六個(gè)月；如果其中一個(gè)坦白，另一個(gè)不坦白；那么坦白者馬上釋放（從寬）、不坦白者將會(huì)判刑九個(gè)月。請(qǐng)問兩個(gè)嫌犯該怎么辦？51Strategy&PayoffsPrisoner’sDStrategy&PayoffsPrisoner’sDilemma(囚犯兩難)策略(Strategy):“沉默”&“招認(rèn)”收益矩陣(PayoffMatrix)如下：囚犯2沉默招認(rèn)囚犯1沉默-1，-1-9，0招認(rèn)0，-9-6，-652Strategy&PayoffsPrisoner’sDStrategy&PayoffsPrisoner’sDilemma(囚犯兩難)囚犯兩難的問題在現(xiàn)實(shí)中常常出現(xiàn)。比如兩家企業(yè)的價(jià)格戰(zhàn)。企業(yè)B遵守協(xié)議違約降價(jià)企業(yè)A遵守協(xié)議100，10030，130違約降價(jià)130，3070，7053Strategy&PayoffsPrisoner’sDStrategy&Payoffs性別戰(zhàn)博弈(TheBattleofSex)一男一女試圖安排一個(gè)晚上的娛樂內(nèi)容選擇（策略）：“歌劇”、“拳擊”；不過男女有別收益矩陣(PayoffMatrix)如下：男(TheMan)歌劇拳擊女(TheLady)歌劇2，10，0拳擊0，01，254Strategy&Payoffs性別戰(zhàn)博弈(TheB5511Strategy&PayoffsOtherExamplesCoordinationgamesSmithandJonesaretryingtodecidewhethertodesignthecomputerstheyselltouselargeorsmallfloppydisksBothplayerswillsellmorecomputersiftheirdiskdrivesarecompatible.Strategies:“Large”or“Small”Payoffsareasfollows.56Strategy&PayoffsOtherExamplStrategy&PayoffsOtherExamplesCoordinationgames:payoffmatrixJonesLargeSmallSmithLarge2,2-1,-1Small-1，-11,157Strategy&PayoffsOtherExamplDominantStrategies(支配策略)Wesayaplayerhasadominantstrategyifitisthestrictlybestresponsetoanystrategiestheotherplayersmightpick.Intheanalysisofanygame,thefirststepistodetermineifanyplayerhasadominantstrategy.Ifsuchastrategyexists,thentheoutcomeofthegameshouldbeeasilydetermined,sincetheplayerwillusethedominantstrategyandotherplayerswillsubsequentlyadopttheirbestresponses.Examples:DoesthePrisoner’sDilemmahaveanydominantstrategy?HowabouttheCoordinationGame?58DominantStrategies(支配策略)WesDominatedStrategies(被支配策略)Adominatedstrategyisanalternativethatyieldsalowerpayoffthansomeotherstrategy,nomatterwhattheotherplayersinthegamedo.Arationalplayerwillneveruseadominatedstrategyintheactualactionofgameplaying.Henceitcanbeeliminated.Itisclearthatiftheexistenceofadominantstrategyimpliesthatallotherchoicesareinfactthedominatedstrategies.Butitispossiblethattherearedominatedstrategies,whilethereisnodominantstrategy59DominatedStrategies(被支配策略)AApplication:IterativeEliminationsExample60Application:IterativeEliminaNashEquilibrium(納什均衡)Eventhoughusingadominantstrategyoradominatedstrategyisapowerfulsimplewayof“solving”agame,thiskindofgameisusuallyanexception,insteadofanorm.Wemusthaveagenericmethodoffindingthesolution(s)ofagame.SolutionConceptsNashEquilibriumistheveryfirstsolutionconceptfornon-cooperativegames.61NashEquilibrium(納什均衡)EventhNashEquilibrium(納什均衡)EssenceofNashEquilibriumANashEquilibriumisdefinedasasetofstrategiessuchthatnonoftheparticipantsinthegamecanimprovetheirpayoff,giventhestrategiesoftheotherparticipants.NoonehasastrictlyincentivetodeviatefromthestrategiesinaNashEquilibrium.62NashEquilibrium(納什均衡)EssenceNashEquilibrium(納什均衡)ExampleConsiderthefollowinggame.Isthereanydominantordominatedstrategy?63NashEquilibrium(納什均衡)ExampleNashEquilibrium(納什均衡)ProblemofNashEquilibrium:Multiplesolutions!Examples:BattleofSex

CoordinationGame男(TheMan)歌劇拳擊女(TheLady)歌劇2，10，0拳擊0，01，2JonesLargeSmallSmithLarge2,2-1,-1Small-1，-11,164NashEquilibrium(納什均衡)ProblemNashEquilibrium(納什均衡)ProblemofNashEquilibrium:Insensitivetoextremepayoffs(risks)Example:DangerousCoordinationGameJonesLargeSmallSmithLarge2,2-1000,-1Small-1，-11,1InPractice,itisalmostsurethatSmithwantsto“playsafe”andnevertry“l(fā)arge”!65NashEquilibrium(納什均衡)ProblemNashEquilibrium(納什均衡)ProblemofNashEquilibrium:Non-existenceofpurestrategyNashEquilibriumExample:MatchthePenniesNodominantstrategy,nodominatedstrategy&nopurestrategyNashequilibriumaswell!BHeadTailAHead1,-1-1,1Tail-1，11,-166NashEquilibrium(納什均衡)ProblemNashEquilibrium(納什均衡)MixedStrategies（混合策略）Amixedstrategyisaprofilethatspecifiestheprobabilityofeachpurestrategythatistobeplayed.NashTheorem:Foranygamewithfinitenumberofpurestrategies,therealwaysexistsaNashEquilibriuminmixedstrategyform.67NashEquilibrium(納什均衡)MixedSNashEquilibrium(納什均衡)MixedStrategies（混合策略）:ExamplesCoordinationGameJonesplays(Large,Small)accordingto(p,1-p)Smith’sexpectedpayoffsare:“Large”:2p+(-1)(1-p)=US(L|(p,1-p))“Small”:(-1)p+1(1-p)=US(S|(p,1-p))Smithshouldbe“indifferent”betweenthetwochoicesUS(L|(p,1-p))=US(S|(p,1-p))p=2/5HenceJones’optimalmixedstrategymustbe(0.4,0.6)Exercise:findtheoptimalmixedstrategyforSmith.MatchingthePenniesFindtheNashequilibriuminmixedstrategies68NashEquilibrium(納什均衡)MixedS69257026NashEquilibrium(納什均衡)NashEquilibrium不一定有效率TheCentipedeGame(蜈蚣蟲游戲):Inthisfinitegameofperfectinformation,therearetwoplayers,1and2.Theplayerseachstartwith1dollarinfrontofthem.Theyalternatesaying‘stop’or‘continue’,startingwithplayer1.Whenaplayersays‘continue’,1dollaristakenbyarefereefromherpileand2dollarsareputinheropponent’spile.Assoonaseitherplayersays‘stop’,plyisterminated,andeachplayerreceivesthemoneycurrentlyinherpile.Alternatively,playstopsifbothplayers’pilesreach100dollars.71NashEquilibrium(納什均衡)NashEqPlayer1Player2Player1Player2Player1Player2SCCCCCCSSSSS11032297100999998101100,10072Player1Player2Player1PlayerMaxminStrategies(最大最小策略)Wheneachplayerinthegamewillselecttheoptionthatmaximizestheminimumpossibleprofit(orotherdesirableoutcome),wesaythatthedecisionruleisamaxminstrategy.Thismayhappeninsituationswhenthemarketishighlycompetitiveanddecisionmakersareriskaverse.Sothisisausefulcaseformanagerialdecisionmaking.73MaxminStrategies(最大最小策略)When

7430迄今為止，對(duì)市場(chǎng)結(jié)構(gòu)分析都以假定管理決策的中心是謀求最大利益。但是在如壟斷寡頭那樣競(jìng)爭(zhēng)十分激烈的場(chǎng)合，決策者可能采取一種風(fēng)險(xiǎn)厭惡政策，即確保在可能的最壞結(jié)果中得到最好的結(jié)果。也就是每個(gè)博弈者將在可能最少的利潤(rùn)方案中選擇利潤(rùn)最大的方案。75迄今為止，對(duì)市場(chǎng)結(jié)構(gòu)分析都以假定管理決策的中心是謀求最大利益（續(xù)）Nash均衡為（3，6）和（6，3）企業(yè)1最小32企業(yè)2最小32結(jié)果：雙方都沒有新產(chǎn)品推出在這個(gè)例子中，Nash不是小中取大解！76（續(xù)）企業(yè)1最小企業(yè)2最小3MaxminStrategies(最大最小策略)Anotherexample:77MaxminStrategies(最大最小策略)AnotSequentialGame(順序性博弈)順序性博弈：先下弈的優(yōu)勢(shì)(First-moverAdvantage)迄今為止，我們都隱含假定雙方下弈者都是同時(shí)實(shí)施。在順序(Sequentialgame)中，就是有先有后了。進(jìn)入新的市場(chǎng)就是一個(gè)順序博弈的例子。78SequentialGame(順序性博弈)順序性博弈：先7935803681378238StrategicBehavior:BarriersofEntryFourtraditionalbarrierstoentry(passive)Economiesofscale,productdifferentiation,controloverscareresources,andlegalfactorsMarketEntryDecision(EntryGame)(aggressive)Presentvs.FutureProfits:Entry-LimitingPricingMainideas:Motivation:short-runMonopolypricingpracticeearns“toomuchprofits”,henceattractnewentrantsthatwilleatupthemarketshareanddrivedownthepricesinthelongrunEntry-LimitPricing:needtosetapricebelowthe