经济博弈论_Chapter18

讨价还价讨价还价BargainingBargaining第18章Chapter18Chapter18讨价还价Bargaining人们在生活中总在进行着讨价还价：Peopleengageinbargainingthroughouttheirlilives:买卖双方在价格上Buyersandsellersoverprice人老板在资上工人和老板在工资上Workersandbossesoverwages国家在相互贸易政策，或在裁军上CountriesoverpoliciesofmutualtradeliberalizationCountriesoverpoliciesofmutualtradeliberalization,ormutualarmsreduction夫妇在购房、择业和抚养孩子上CouplesoverhousingcareerschildrearingetcCouplesoverhousing,careers,childrearing,etc.儿童在分享玩具和做游戏上ChildrenoversharingtoysandplayinggamesSlide2……讨价还价Bargaining所有的讨价还价问题有两个共同点。Allbargainingsituationshavetwothingsingggcommon.首先，谈判各方达成一致所能够产生和得到的总收益应该比他们独立行动所能得到的个人收益之和要大应该比他们独立行动所能得到的个人收益之和要大。First,thetotalpayoffthatthepartiestothenegotiationarecapableofcreatingandgpgenjoyingasaresultofreachinganagreementshouldbegreaterthanthesumoftheindividualpayoffsthattheycouldachieveindividualpayoffsthattheycouldachieveseparately.其次，这不是一个零和博弈。Slide3其次这不是个零和博弈Second,itisnotazero-sumgame.讨价还价Bargaining表面看起来是一个零和博弈：当剩余存在时，谈判就是为了瓜分它。每个讨价还价者都试图让自己多得，而留给别人更少。Itmayappeartobezero-sum:whenasurplusexists,tayappeatobeeosueasupusests,thenegotiationisabouthowtodivideitup.Eachbargainertriestogetmoreforhimselfandleavelessfortheothers.但在这背后隐藏着一个危险，如果协议未能达成，没有人可以得到任何一点剩余。Butbehinditliesthedangerthat,iftheagreementisg,gnotreached,noonewillgetanysurplusatall.这一不利于双方的结果，以及双方都要避免之的愿望，为威胁（明显的或隐含的）创造了可能，这就使得讨价还价成为一个策（明显的或隐含的）创造了可能，这就使得讨价还价成为个策略问题。Thismutuallyharmfulalternative,aswellasbothparties’desiretoavoidit,iswhatcreatesthepotentialSlide4p,pforthethreats–explicitandimplicit–thatmakebargainingsuchastrategicmatter.讨价还价Bargaining在博弈论产生之前，一对一的谈判一般被认为是困难的甚至是没有定论的一个问题。的甚是没有定的个问题Beforetheadventofgametheory,one-on-onebargainingwasgenerallythoughttobeadifficultandevenindeterminateproblemdifficultandevenindeterminateproblem.对于为什么一方比另一方多得，理论家不能找到一个有条理的解释，只好把这一结果归因于含糊不清的有条理的解释，只好把这结果归因于含糊不清的“讨价还价能力”的差别上。TheoristswerenotabletoachieveanysystematicunderstandingofwhyonepartysystematicunderstandingofwhyonepartygetsmorethananotherandattributedthisresulttovagueandinexplicabledifferencesinSlide5“bargainingpower.”讨价还价Bargaining即使是简单的纳什均衡理论也不能起作用。EventhesimpletheoryofNashequilibriumpyqdoesnottakeusanyfarther.假定2个人分1美元。要求每个人同时报出其想要的数量。Supposetwopeoplearetosplit$1EachisaskedtoSupposetwopeoplearetosplit$1.Eachisaskedtoannouncewhathewant,simultaneously.如果他们所报数量x和y加起来等于或小于1，每个人得到其所报的量否则一无所获所报的量。否则无所获。Iftheirannouncementsxandyaddupto1orless,eachgetwhatheannounced.Otherwiseneithergetanythinganything.那么任何一对(x,y)，只要加起来等于1，都构成了该博弈的纳什均衡。Thenanypair(xy)addingto1constituteaNashSlide6Thenanypair(x,y)addingto1constituteaNashequilibriuminthisgame.讨价还价Bargaining一种分析途径是把讨价还价看成合作博弈这里各方共同寻找和实施一个解弈。这里，各方共同寻找和实施一个解决方案，可能找一个中立的第三方来作为执行的仲裁者为执行的仲裁者。Oneapproachviewsbargainingasacooperativegameinwhichtheacooperativegame,inwhichthepartiesfindandimplementaltijitlhisolutionjointly,perhaps,usinganeutralthirdpartyasanarbitratorfftSlide7forenforcement.讨价还价Bargaining另一种分析途径将讨价还价作为一个非合作博弈这里各方独立地选择策略弈，这里，各方独立地选择策略。Theotherapproachviewsbargainingasanoncooperativegameinwhichtheanoncooperativegame,inwhichthepartieschoosestrategiesseparately.我们会具体分析个出价与还价的序贯博弈我们会具体分析一个出价与还价的序贯博弈，该博弈会导出一个确定的均衡。WiftilfWespecifyasequential-movegameofofferandcounteroffers,whichleadstodtitilibiSlide8adeterminateequilibrium.内容提要Outline纳什合作解纳什合作解Nash’scooperativesolution可变威胁的讨价还价可变威胁的讨价还价Variable-threatbargaining轮流出价模型I：总价值衰减Alternating-offersmodelI:totalvaluedecays实验证据ExperimentalEvidenceExperimentalEvidence轮流出价模型II：不耐烦Alternating-offersmodelII:impatienceAlternatingoffersmodelII:impatience讨价还价中的信息操纵ManipulatinginformationinbargainingSlide9与多方和就多个事项进行讨价还价Bargainingwithmanypartiesandissues纳什合作解Nash’sCooperativeSolution考虑两家硅谷的企业，安迪和比尔。ImaginetwoSiliconValleyentrepreneurs,AndyandBill.安迪生产微芯片他可以以900美元的价格卖给任何一家计算机安迪生产微芯片，他可以以900美元的价格卖给任何家计算机制造商。比尔的软件包可以以100美元的价格进行零售。Andyproducesamicrochipsetwhichhecanselltoanycomputermanufacturerfor$900.Billhasasoftwarecomputermanufacturerfor$900.Billhasasoftwarepackagethatcanretailfor$100.两个人凑在一起，发现他们可以生产一个软硬件的联合产品，卖到3000美元。到3,000美元。Thetwomeetandrealizethattheycanproduceacombinedsystemofhardwareandsoftwareworth$3,000.$3,000.对于这每单位3,000美元的收益（或2,000美元的额外收益），安迪和比尔各应得多少？Ofthe$3,000revenue(or$2,000extrarevenue)fromSlide10Ofthe$3,000revenue(or$2,000extrarevenue)fromeachunit,howmuchshouldgotoAndyandhowmuchtoBill?纳什合作解Nash’sCooperativeSolution如果两人直接面对面地谈判，昀终的协议取决于二人的倔强和耐心。ThefinalagreementdependsontheirThefinalagreementdependsontheirstubbornnessorpatienceiftheynegotiatedirectlywitheachother.y如果他们试图让一个第三方来仲裁这一争端，仲裁者的决定则取决于他对于硬件和软件相对价值的判断，以及两个当事人在他面前陈词的表现力以及两个当事人在他面前陈词的表现力。Iftheytrytohavethedisputearbitratedbyathirdparty,thearbitrator’sdecisiondependspy,ponhissenseoftherelativevalueofhardwareandsoftwareandontherhetoricalskillofthetwoprincipalsastheypresenttheirargumentsSlide11twoprincipalsastheypresenttheirargumentsbeforethearbitrator.纳什合作解Nash’sCooperativeSolution假定仲裁者决定利润的分配应为4:1，安迪得4。SupposethearbitratordecidesthattheSupposethearbitratordecidesthatthedivisionoftheprofitshouldbe4:1infavorofAndy.y假定安迪总收益为x，比尔为y。那么，SupposeAndygetsatotalofxandBillppyggetsatot