ackerlof-market for lemons

学术人物阿克洛夫、斯彭斯和斯蒂格利茨的微观信息经济学理论及其应用唐久红 唐岳驹一、前　言 2001年10月10日,瑞典皇家科学院将该年度诺贝尔经济学奖授予美国伯克利加利福尼亚大学经济学教授乔治・阿克洛夫(G eorge A1Akerlof)、美国哈佛大学和斯坦福大学经济学教授迈克尔・斯彭斯(A1Michael S pence)与美国哥伦比亚大学经济学教授约瑟夫・斯蒂格利茨(Joseph E1Stiglitz),以表彰三位美国学者对微观信息经济学(不对称信息市场)理论及其应用所作出的杰出贡献。

瑞典皇家科学院在颁奖书中说,本年度的获奖者在20世纪70年代用不对称信息(Asymmetric in formation)为广泛的市场理论奠定了基础。

三位美国经济学家的贡献形成了现代微观信息经济学理论的核心,其实际应用非常广泛,不仅包括传统的农业市场,而且包括现代的金融市场。

关于三位获奖者提出的所谓“柠檬”(Lem ons,二手车在美国被称为“柠檬”)作用力量及其有时反常的结果的信息市场理论,西方著名学者、瑞典隆德大学经济学教授安德斯・博里林评论说,许多人之所以本能地不信任二手车经销商,其理论就在于此,因为他们往往比顾客更了解待出售的二手车。

同样,公民也比税收当局更了解自己的个人财务状况。

这就是“不对称信息”。

瑞典皇家科学院在颁奖说明中还特别表明,在三位获奖者中,斯蒂格利茨对不对称信息经济学理论的贡献最大。

斯蒂格利茨在经济理论方面的许多贡献,诸如道德风险(M o2 ral Hazard)、逆向选择(Adverse Selection)、信息甄别、信贷配给、市场效率、组织与财务结构、新古典增长以及宏观经济学的微观基础等许多方面,都改变了经济学家分析研究市场运作的方式。

斯蒂格利茨的不对称信息理论与阿克洛夫的“柠檬”原理及斯彭斯的劳动市场模型等相关理论构成了当代微观信息经济学的牢固基石。

这不仅在西方,而且在广大发展中国家都具有广泛的现实意义。

Financing Constraints and Corporate InvestmentSteven M.Fazzari;R.Glenn Hubbard;Bruce C.Petersen;Alan S.Blinder;James M.PoterbaBrookings Papers on Economic Activity,Vol.1988,No.1.(1988),pp.141-206.Stable URL:/sici?sici=0007-2303%281988%291988%3A1%3C141%3AFCACI%3E2.0.CO%3B2-OBrookings Papers on Economic Activity is currently published by The Brookings Institution.Your use of the JSTOR archive indicates your acceptance of JSTOR's Terms and Conditions of Use,available at/about/terms.html.JSTOR's Terms and Conditions of Use provides,in part,that unless you have obtained prior permission,you may not download an entire issue of a journal or multiple copies of articles,and you may use content in the JSTOR archive only for your personal,non-commercial use.Please contact the publisher regarding any further use of this work.Publisher contact information may be obtained at/journals/brookings.html.Each copy of any part of a JSTOR transmission must contain the same copyright notice that appears on the screen or printed page of such transmission.The JSTOR Archive is a trusted digital repository providing for long-term preservation and access to leading academic journals and scholarly literature from around the world.The Archive is supported by libraries,scholarly societies,publishers, and foundations.It is an initiative of JSTOR,a not-for-profit organization with a mission to help the scholarly community take advantage of advances in technology.For more information regarding JSTOR,please contact support@.Thu Mar1304:08:182008。

Journal of Economic Perspectives—Volume16,Number3—Summer2002—Pages171–195 The Theory of the Firm as Governance Structure:From Choice to Contract Oliver E.WilliamsonT he propositions that organization matters and that it is susceptible to analysis were long greeted by skepticism by economists.To be sure,therewere conspicuous exceptions:Alfred Marshall in Industry and Trade (1932),Joseph Schumpeter in Capitalism,Socialism,and Democracy(1942)and Friedrich Hayek(1945)in his writings on knowledge.Institutional economists like Thorstein Veblen(1904),John mons(1934)and Ronald Coase(1937)and organization theorists like Robert Michels(1915[1962]),Chester Barnard(1938), Herbert Simon(1957a),James March(March and Simon,1958)and Richard Scott (1992)also made the case that organization deserves greater prominence.One reason why this message took a long time to register is that it is much easier to say that organization matters than it is to show how and why.1The prevalence of the science of choice approach to economics has also been an obstacle.As developed herein,the lessons of organization theory for economics are both different and more consequential when examined through the lens of con-tract.This paper examines economic organization from a science of contract perspective,with special emphasis on the theory of the rm.1A Behavioral Theory of the Firm(Cyert and March,1963)was one obvious early candidate for an economic theory of organizations.It deals,however,with more ne-grained phenomena—such as predicting department store prices to the penny—than were of interest to most economists.For a discussion,see Williamson(1999b).The recent and growing interest in behavioral economics—which deals more with the theory of consumer behavior than with the theory of the rm—can be interpreted as a delayed response to the lessons of the“Carnegie school”associated with Cyert,March and Simon.y Oliver E.Williamson is Edgar F.Kaiser Professor of Business Administration,Professor of Economics and Professor of Law,all at the University of California,Berkeley.His e-mail address is owilliam@.172Journal of Economic PerspectivesThe Sciences of Choice and ContractEconomics throughout the twentieth century has been developed predomi-nantly as a science of choice.As Lionel Robbins famously put it in his book,An Essay on the Nature and Signi cance of Economic Science(1932,p.16),“Economics is the science which studies human behavior as a relationship between ends and scarce means which have alternative uses.”Choice has been developed in two parallel constructions:the theory of consumer behavior,in which consumers maximize utility,and the theory of the rm as a production function,in which rms maximize pro t.Economists who work out of such setups emphasize how changes in relative prices and available resources in uence quantities,a project that became the “dominant paradigm”for economics throughout the twentieth century(Reder, 1999,p.48).But the science of choice is not the only lens for studying complex economic phenomena,nor is it always the most instructive lens.The other main approach is what James Buchanan(1964a,b,1975)refers to as the science of contract.Indeed, Buchanan(1975,p.225)avers that economics as a discipline went“wrong”in its preoccupation with the science of choice and the optimization apparatus associated therewith.Wrong or not,the parallel development of a science of contract was neglected.As perceived by Buchanan(1987,p.296),the principal needs for a science of contract were for the eld of public nance and took the form of public ordering:“Politics is a structure of complex exchange among individuals,a structure within which persons seek to secure collectively their own privately de ned objectives that cannot be ef ciently secured through simple market exchanges.”Thinking con-tractually in the public ordering domain leads into a focus on the rules of the game. Constitutional economics issues are posed(Buchanan and Tullock,1962;Brennan and Buchanan,1985).Whatever the rules of the game,the lens of contract is also usefully brought to bear on the play of the game.This latter is what I refer to as private ordering,which entails efforts by the immediate parties to a transaction to align incentives and to craft governance structures that are better attuned to their exchange needs.The object of such self-help efforts is to realize better the“mutuality of advantage from voluntary exchange...[that is]the most fundamental of all understandings in economics”(Buchanan,2001,p.29),due allowance being made for the mitigation of contractual hazards.Strategic issues—to which the literatures on mechanism design,agency theory and transaction cost economics/incomplete contracting all have a bearing—that had been ignored by neoclassical economists from1870to 1970now make their appearance(Makowski and Ostroy,2001,pp.482–483, 490–491).Figure1sets out the main distinctions.The initial divide is between the science of choice(orthodoxy)and the science of contract.The latter then divides into public ordering(constitutional economics)and private ordering parts,where the second is split into two related branches.One branch concentrates on front-endincentive alignment (mechanism design,agency theory,the formal property rights literature),while the second branch features the governance of ongoing contrac-tual relations (contract implementation).This paper is mainly concerned with governance,especially with reference to the theory of the rm.Organization Theory through the Lens of ContractOrganization theory is a huge subject.Macro and micro parts are commonly distinguished,where the former is closer to sociology and the latter to social psychology.Also,it is common to distinguish among rational,natural and open systems approaches (Scott,1992).My concern is with macro organization theory of a rational systems kind (with special reference to the contributions of Herbert Simon).In addition to delimiting organization theory in this way,I also examine the lessons of organization theory for economics not through the lens of choice,but through the lens of contract.Whereas those who work out of the dominant paradigm have sometimes been dismissive of organization theory (Posner,1993;Reder,1999,pp.46–49),the lens of contract/private ordering discloses that lessons of organization theory for economics that the dominant paradigm obscures are sometimes fundamental.Five Lessons from Organization Theory to the Economics of ContractsA rst lesson from organization theory is to describe human actors in more realistic terms.Simon (1985,p.303)is unequivocal:“Nothing is more fundamental in setting our research agenda and informing our research methods than our view of the nature of the human beings whose behavior we are studying.”Socialscientists Figure 1The Sciences of Choice and ContractOliver E.Williamson 173174Journal of Economic Perspectivesare thus invited(challenged)to name the cognitive,self-interest and other at-tributes of human actors on which their analyses rest.Bounded rationality is the cognitive assumption to which Simon(1957a, p.xxiv)refers,by which he has reference to behavior that is intendedly rational,but only limitedly so.In his view,the main lesson for the science of choice is to supplant maximizing by“satis cing”(1957b,p.204)—the quest for an alternative that is “good enough.”2The study of governance also appeals to bounded rationality,but the main lesson for the science of contract is different:All complex contracts are unavoidably incomplete.For this reason,parties will be confronted with the need to adapt to unanticipated disturbances that arise by reason of gaps,errors and omissions in the original contract.Such adaptation needs are especially consequential if,instead of describing self-interest as“frailty of motive”(Simon,1985,p.303),which is a comparatively benign condition,strategic considerations are entertained,as well.If human actors are not only confronted with needs to adapt to the unforeseen(by reason of bounded rationality),but are also given to strategic behavior(by reason of opportunism),then costly contractual breakdowns(refusals of cooperation, maladaptation,demands for renegotiation)may be posed.In that event,private ordering efforts to devise supportive governance structures,thereby to mitigate prospective contractual impasses and breakdowns,have merit.To be sure,such efforts would be unneeded if common knowledge of payoffs and costless bargaining are assumed.Both of these conditions,however,are deeply problematic(Kreps and Wilson,1982;Williamson,1985).Moreover,because prob-lems of nonveri ability are posed when bounded rationality,opportunism and idiosyncratic knowledge are joined(Williamson,1975,pp.31–33),dispute resolu-tion by the courts in such cases is costly and unreliable.Private ordering—that is, efforts to craft governance structure supports for contractual relations during the contract implementation interval—thus makes its appearance.A second lesson of organization theory is to be alert to all signi cant behavioral regularities whatsoever.For example,efforts by bosses to impose controls on workers have both intended and unintended consequences.Out of awareness that workers are not passive contractual agents,na¨ve efforts that focus entirely on intended effects will be supplanted by more sophisticated mechanisms where provision is made for consequences of both kinds.More generally,the awareness among sociologists that“organization has a life of its own”(Selznick,1950,p.10) serves to uncover a variety of behavioral regularities(of which bureaucratization is one)for which the student of governance should be alerted and thereafter factor into the organizational design calculus.A third lesson of organization theory is that alternative modes of governance 2Although satis cing is an intuitively appealing concept,it is very hard to implement.Awaiting further developments,the satis cing approach is not broadly applicable(Aumann,1985,p.35).Indeed,there is an irony:neoclassical economists who use a mode of analysis(maximizing)that is easy to implement and often is good enough for the purposes at hand are analytical satis cers.The Theory of the Firm as Governance Structure:From Choice to Contract175 (markets,hybrids, rms,bureaus)differ in discrete structural ways(Simon,1978, pp.6–7).Not only do alternative modes of governance differ in kind,but each generic mode of governance is de ned by an internally consistent syndrome of attributes—which is to say that each mode of governance possesses distinctive strengths and weaknesses.As discussed below,the challenge is to enunciate the relevant attributes for describing governance structures and thereafter to align different kinds of transactions with discrete modes of governance in an economiz-ing way.A fourth lesson of the theory of organizations is that much of the action resides in the microanalytics.Simon(1957a,p.xxx)nominated the“decision premise”as the unit of analysis,which has an obvious bearing on the microanalytics of choice (Newell and Simon,1972).The unit of analysis proposed by John mons, however,better engages the study of contract.According to Commons(1932,p.4),“the ultimate unit of activity...must contain in itself the three principles of con ict,mutuality,and order.This unit is a transaction.”Whatever the unit of analysis,operationalization turns on naming and expli-cating the critical dimensions with respect to which the unit varies.Three of the key dimensions of transactions that have important rami cations for governance are asset speci city(which takes a variety of forms—physical,human,site,dedicated, brand name—and is a measure of bilateral dependency),the disturbances to which transactions are subject(and to which potential maladaptations accrue)and the frequency with which transactions recur(which bears both on the ef cacy of reputation effects in the market and the incentive to incur the cost of specialized internal governance).Given that transactions differ in their attributes and that governance structures differ in their costs and competencies,the aforemen-tioned—that transactions should be aligned with appropriate governance struc-tures—applies.A fth lesson of organization theory is the importance of cooperative adapta-tion.Interestingly,both the economist Friedrich Hayek(1945)and the organiza-tion theorist Chester Barnard(1938)were in agreement that adaptation is the central problem of economic organization.Hayek(1945,pp.526–527)focused on the adaptations of autonomous economic actors who adjust spontaneously to changes in the market,mainly as signaled by changes in relative prices.The marvel of the market resides in“how little the individual participants need to know to be able to take the right action.”By contrast,Barnard featured coordinated adaptation among economic actors working through deep knowledge and the use of admin-istration.In his view,the marvel of hierarchy is that coordinated adaptation is accomplished not spontaneously,but in a“conscious,deliberate,purposeful”way (p.9).Because a high-performance economic system will display adaptive properties of both kinds,the problem of economic organization is properly posed not as markets or hierarchies,but rather as markets and hierarchies.A predictive theory of economic organization will recognize how and why transactions differ in their176Journal of Economic Perspectivesadaptive needs,whence the use of the market to supply some transactions and recourse to hierarchy for others.Follow-on Insights from the Lens of ContractExamining economic organization through the lens of contract uncovers additional regularities to which governance rami cations accrue.Three such reg-ularities are described here:the Fundamental Transformation,the impossibility of replication/selective intervention and the idea of contract laws(plural).The Fundamental Transformation applies to that subset of transactions for which large numbers of quali ed suppliers at the outset are transformed into what are,in effect,small numbers of actual suppliers during contract execution and at the contract renewal interval.The distinction to be made is between generic transactions where“faceless buyers and sellers...meet...for an instant to ex-change standardized goods at equilibrium prices”(Ben-Porath,1980,p.4)and exchanges where the identities of the parties matter,in that continuity of the relation has signi cant cost consequences.Transactions for which a bilateral depen-dency condition obtains are those to which the Fundamental Transformation applies.The key factor here is whether the transaction in question is supported by investments in transaction-speci c assets.Such specialized investments may take the form of specialized physical assets(such as a die for stamping out distinctive metal shapes),specialized human assets(that arise from rm-speci c training or learning by doing),site speci city(specialization by proximity),dedicated assets(large discrete investments made in expectation of continuing business,the premature termination of which business would result in product being sold at distress prices) or brand-name capital.Parties to transactions that are bilaterally dependent are “vulnerable,”in that buyers cannot easily turn to alternative sources of supply,while suppliers can redeploy the specialized assets to their next best use or user only at a loss of productive value(Klein,Crawford and Alchian,1978).As a result,value-preserving governance structures—to infuse order,thereby to mitigate con ict and to realize mutual gain—are sought.3Simple market exchange thus gives way to credible contracting,which includes penalties for premature termination,mecha-nisms for information disclosure and veri cation,specialized dispute settlement procedures and the like.Uni ed ownership(vertical integration)is predicted as bilateral dependency hazards build up.The impossibility of combining replication with selective intervention is the transaction cost economics answer to an ancient puzzle:What is responsible for limits to rm size?Diseconomies of large scale is the obvious answer,but wherein do these diseconomies reside?Technology is no answer,since each plant in a 3Bilateral dependency need not result from physical asset speci city if the assets are mobile,since a buyer who owns and who can repossess the assets can assign them to whichever supplier tenders the lowest bid.Also,site speci c assets can sometimes be owned by a buyer and leased to a supplier. Nonetheless,such“solutions”will pose user cost problems if suppliers cannot be relied upon to exercise due care.Oliver E.Williamson177 multiplant rm can use the least-cost technology.Might organization provide the answer?That possibility can be examined by rephrasing the question in compara-tive contractual terms:Why can’t a large rm do everything that a collection of small suppliers can do and more?Were it that large rms could replicate a collection of small rms in all circumstances where small rms do well,then large rms would never do worse.If, moreover,large rms could always selectively intervene by imposing(hierarchical) order on prospective con ict,but only where expected net gains could be pro-jected,then large rms would sometimes do better.Taken together,the combina-tion of replication with selective intervention would permit large rms to grow without limit.Accordingly,the issue of limits to rm size turns to an examination of the mechanisms for implementing replication and selective intervention.Examining how and why both replication and selective intervention break down is a tedious,microanalytic exercise and is beyond the scope of this paper (Williamson,1985,chapter6).Suf ce it to observe here that the move from autonomous supply(by the collection of small rms)to uni ed ownership(in one large rm)is unavoidably attended by changes in both incentive intensity(incentives are weaker in the integrated rm)and administrative controls(controls are more extensive).Because the syndromes of attributes that de ne markets and hierarchies have different strengths and weaknesses,some transactions will bene t from the move from market to hierarchy while others will not.Yet another organizational dimension that distinguishes alternative modes of governance is the regime of contract laws.Whereas economic orthodoxy often implicitly assumes that there is a single,all-purpose law of contract that is costlessly enforced by well-informed courts,the private ordering approach to governance postulates instead that each generic mode of governance is de ned(in part)by a distinctive contract law regime.The contract law of(ideal)markets is that of classical contracting,according to which disputes are costlessly settled through courts by the award of money damages.Galanter(1981,pp.1–2)takes issue with this legal centralism tradition and observes that many disputes between rms that could under current rules be brought to a court are resolved instead by avoidance,self-help and the like.That is because in“many instances the participants can devise more satisfactory solutions to their disputes than can professionals constrained to apply general rules on the basis of limited knowledge of the dispute”(p.4).Such a view is broadly consonant with the concept of“contract as framework”advanced by Karl Llewellyn(1931, pp.736–737),which holds that the“major importance of legal contract is to provide...a framework which never accurately indicates real working relations, but which affords a rough indication around which such relations vary,an occa-sional guide in cases of doubt,and a norm of ultimate appeal when the relations cease in fact to work.”This last condition is important,in that recourse to the courts for purposes of ultimate appeal serves to delimit threat positions.The more elastic concept of contract as framework nevertheless supports a(cooperative)exchange relation over a wider range of contractual disturbances.178Journal of Economic PerspectivesWhat is furthermore noteworthy is that some disputes cannot be brought to a court at all.Speci cally,except as“fraud,illegality or con ict of interest”are shown, courts will refuse to hear disputes that arise within rms—with respect,for exam-ple,to transfer pricing,overhead,accounting,the costs to be ascribed to intra rm delays,failures of quality and the like.In effect,the contract law of internal organization is that of forbearance,according to which a rm becomes its own court of ultimate appeal.Firms for this reason are able to exercise at that the markets cannot.This,too,in uences the choice of alternative modes of governance.Not only is each generic mode of governance de ned by an internally consis-tent syndrome of incentive intensity,administrative controls and contract law regime(Williamson,1991a),but different strengths and weaknesses accrue to each. The Theory of the Firm as Governance StructureAs Demsetz(1983,p.377)observes,it is“a mistake to confuse the rm of [orthodox]economic theory with its real-world namesake.The chief mission of neoclassical economics is to understand how the price system coordinates the use of resources,not the inner workings of real rms.”Suppose instead that the assigned mission of economics is to understand the organization of economic activity.In that event,it will no longer suf ce to describe the rm as a black box that transforms inputs into outputs according to the laws of technology.Instead, rms must be described in relation to other modes of governance,all of which have internal structure,which structure“must arise for some reason”(Arrow,1999, p.vii).The contract/private ordering/governance(hereafter governance)approach maintains that structure arises mainly in the service of economizing on transaction costs.Note in this connection that the rm as governance structure is a comparative contractual construction.The rm is conceived not as a stand-alone entity,but is always to be compared with alternative modes of governance.By contrast with mechanism design(where a menu of contracts is used to elicit private informa-tion),agency theory(where risk aversion and multitasking are featured)and the property rights theory of the rm(where everything rests on asset ownership),the governance approach appeals to law and organization theory in naming incentive intensity,administrative control and contract law regime as three critical attributes.It will be convenient to illustrate the mechanisms of governance with reference to a speci c class of transactions.Because transactions in intermediate product markets avoid some of the more serious conditions of asymmetry—of information, budget,legal talent,risk aversion and the like—that beset some transactions in nal product markets,I examine the“make-or-buy”decision.Should a rm make an input itself,perhaps by acquiring a rm that makes the input,or should it purchase the input from another rm?The Theory of the Firm as Governance Structure:From Choice to Contract179 The Science of Choice Approach to the Make-or-Buy DecisionThe main way to examine the make-or-buy decision under the setup of rm as production function is with reference to bilateral monopoly.4The neoclassical analysis of bilateral monopoly reached the conclusion that while optimal quantities between the parties might be realized,the division of pro ts between bilateral monopolists was indeterminate(for example,Machlup and Tabor,1960,p.112). Vertical integration might then arise as a means by which to relieve bargaining over the indeterminacy.Alternatively,vertical integration could arise as a means by which to restore ef cient factor proportions when an upstream monopolist sold intermediate product to a downstream buyer that used a variable proportions technology(McKenzie,1951).Vertical integration has since been examined in a combined variable proportions-monopoly power context by Vernon and Graham (1971),Schmalensee(1973),Warren-Boulton(1974),West eld(1981)and Hart and Tirole(1990).This literature is instructive,but it is also beset by a number of loose ends or anomalies.First,since preexisting monopoly power of a durable kind is the excep-tion in a large economy rather than the rule,what explains vertical integration for the vast array of transactions where such power is negligible?Second,why don’t rms integrate everything,since under a production function setup,an integrated rm can always replicate its unintegrated rivals and can sometimes improve on them?Third,what explains hybrid modes of contracting?More generally,if many of the problems of trading are of an intertemporal kind in which successive adaptations to uncertainty are needed,do the problems of economic organization have to be recast in a larger and different framework?Coase and the Make-or-Buy DecisionCoase’s(1937)classic article opens with a basic puzzle:Why does a rm emerge at all in a specialized exchange economy?If the answer resides in entre-preneurship,why is coordination“the work of the price mechanism in one case and the entrepreneur in the other”(p.389)?Coase appealed to transaction cost economizing as the hitherto missing factor for explaining why markets were used in some cases and hierarchy in other cases and averred(p.391):“The main reason why it is pro table to establish a rm would seem to be that there is a cost of using the price mechanism,the most obvious...[being]that of discovering what the relevant prices are.”This sounds plausible.But how is it that internal procurement by the rm avoids the cost of price discovery?The“obvious”answer is that sole-source internal supply avoids the need to consult the market about prices,because internal accounting prices of a formulaic 4Although the bilateral monopoly explanation is the oldest explanation and the one emphasized in most microeconomics textbooks,three other price-theoretic frameworks have been used to explain the make-or-buy decision:price discrimination,barriers to entry and strategic purposes.For a summary of the arguments on these points,see Williamson(1987,pp.808–809).For a more complete discussion, see Perry(1989).180Journal of Economic Perspectiveskind(say,of a cost-plus kind)can be used to transfer a good or service from one internal stage to another.If,however,that is the source of the advantage of internal organization over market procurement,the obvious lesson is to apply this same practice to outside procurement.The rm simply advises its purchasing of ce to turn a blind eye to the market by placing orders,period by period,with a quali ed sole-source external supplier who agrees to sell on cost-plus terms.In that event, rm and market are put on a parity in price discovery respects—which is to say that the price discovery burden that Coase ascribes to the market does not survive comparative institutional scrutiny.5In the end,Coase’s profoundly important challenge to orthodoxy and his insistence on introducing transactional considerations does not lead to refutable implications(Alchian and Demsetz,1972).Operationalization of these good ideas was missing(Coase,1992,pp.716–718).The theory of the rm as governance structure is an effort to infuse operational content.Transaction cost economizing is the unifying concept.6A Heuristic Model of Firm as Governance StructureExpressed in terms of the“Commons triple”—the notion that the transaction incorporates the three aspects of con ict,mutuality and order—governance is the means by which to infuse order,thereby to mitigate con ict and to realize“the most fundamental of all understandings in economics,”mutual gain from voluntary exchange.The surprise is that a concept as important as governance should have been so long neglected.The rudiments of a model of the rm as governance structure are the at-tributes of transactions,the attributes of alternative modes of governance and the purposes served.Asset speci city(which gives rise to bilateral dependency)and uncertainty(which poses adaptive needs)are especially important attributes of transactions.The attributes that de ne a governance structure include incentive intensity,administrative control and the contract law regime.In this framework, market and hierarchy syndromes differ as follows:under hierarchy,incentive intensity is less,administrative controls are more numerous and discretionary,and internal dispute resolution supplants court ordering.Adaptation is taken to be the main purpose,where the requisite mix of autonomous adaptations and coordi-nated adaptations vary among transactions.Speci cally,the need for coordinated adaptations builds up as asset speci city deepens.In a heuristic way,Figure2shows the transaction cost consequences of organ-5It does not suf ce to argue that vigilance is unneeded for trade within rms because transfer prices are a wash.For one thing,different transfer prices will induce different factor proportions in divisionalized rms where divisions are held accountable for their bottom lines(unless xed proportions are imposed).Also,because incentives within rms are weaker,ready access to the pass-through of costs can encourage cost excesses.The overarching point is this:to focus on transfer pricing to the neglect of discrete structural differences between rm and market is to miss the forest for the trees.6Other purposes include choice of ef cient factor proportions,specialization of labor(in both physical and cognitive respects)and knowledge acquisition and development.。

市场有效性、长期收益与行为金融学1尤金·法玛芝加哥大学商学院，芝加哥，IL 60637，美国1997年3月17日收稿；1997年10月3日校订摘要市场有效在研究长期收益的文献里存有挑战。

与市场有效假说并存的异象是机会结果,对信息的明显的过度反应和反应不足同样常见,并且关于事件前的异常收益,其事件后的延续和事件后的反转出现的概率一样频繁。

最重要的是，与市场有效预言一致的是，明显的异象可以归因于方法问题，技术方法上的合理改变能让大多数的长期收益异象倾向于消失。

（1998 Elsevier科学有限公司保留所有版权）JEL分类：G14；G12关键词：市场有效性；行为金融学1.引言法玛等人（1969）的事件研究，在股票价格如何对信息作出反应方面提供有用的证据。

许多研究聚焦于一个日期确定的事件在短期时间窗口前后几天的收益。

这一方法的优势是，因为每天的预期收益接近于零，预期收益模型对异常收益的推论没有大的影响。

1聚焦于短期收益窗口的研究假设是，任何滞后窗口在价格对事件的反应是短暂的。

有一个发展中的文献质疑这种假设，它认为股票价格对信息的调整缓慢，所以必须用长远的眼光检验收益，来获取市场无效的一个全视图。

如果接受他们提出的结论，最近许多关于长期收益的研究都表明市场无效，具体地说就是，对于信息的长期的反应不足或过度反应。

然而现在我们质问这个学科，总的来看，效率是否应该被丢弃。

我的回答是绝对不行，有以下两个原因。

首先，一个有效的市场产生各种类别的事件，个别事件暗示价格对信息反应过度。

但在一个有效率的市场，明显的反应不足将和反应过度一样频繁。

如果异象在反应不足和反应过度之间随机发生，他们将导致市场有效。

我们应当看到，明显的反应过度和反应不足之间大致平均的分布可以很好的描述现有异象。

其次，更重要的是，如果长期收益的异象很大以至于不能归因于概率，那么在过度反应和反应不足之间的平均分布是市场效率的胜利。

然而我们发现，长期1Brad Barber，David Hirshleifer，S.P.Kothari，Owen Lamont，Mark Mitchell，Hersh Shefrin，Robert Shiller，Rex Sinquefield，Richard Thaler，Theo Vermaelen，RobertVishny，Ivo Welch 的评论和审阅对本文有过帮助。

美国耶鲁大学网络公开课《金融市场》视频笔记14耶鲁大学网络公开课《金融市场》由罗伯特.J.希勒（Robert J. Shiller）教授主讲。

共26课（集），每课时长均为一个多小时，配有字幕。

[第14课] 安德鲁·雷德利夫的客座演讲（时长1小时15分）（关于安德鲁·雷德利夫，在上节课开头已有过介绍，所以，在这个讲座，安德鲁·雷德利夫上来就开讲了）我要说的第一件事，是我认为，当你们在考虑金融市场时，大多数人所想的第一件事或第一个问题是，那些市场是否有效？是否包含了所有已知的信息？如果能够做到这些，那在一定程度上，金融市场显然就比整个市场还好（笑）。

我不确定，曾经是绝对吸纳了经济学智慧的金融市场，就是有效了？我认为，到现在，这种观点还是主流的学术观点。

但是，对此存在着激烈的争论，双方都有代言人。

对我来说，实际上，这是一个非常简单的问题。

关于市场有效的概念，源于一个先验的理论，该理论是关于所有市场的，认为有很多动机，激励人们按照自己的兴趣采取行动，也只能这样去做。

这是一种非常吸引人的先验理论，但是，作为理论，是用来进行预测的。

如果预测的一些事情并没有成为事实，那么这个理论就被摒弃，这样的理论有很多很多。

有很多与金融市场有效性相反的例子。

在某种程度上，有这样的事情，有些公司拥有两种不同类别的股票，而在经济意义上相同。

比如，皇家壳牌公司（Royal Shell）就曾经拥有过在荷兰交易的荷兰股份，以及在英国交易的英国股份，两者在经济意义上相同，但价格会有波动且非常剧烈。

在1998年时期，有一只这种类型的股票，比起另一只股票要打折20%，并持续了好几年。

因此，你拥有经济意义上相同的东西，会以不同的价格进行交易。

例如，你持有封闭式基金（closed end funds），这是一种拥有一组其他证券的金融工具，封闭式基金是作为一种债券在证券交易所进行挂牌交易，而这种基金所做的事，就是持有其他的证券。

《产业组织理论》参考教材及经典文献选读一、参考教材：1.廖进球主编：产业组织理论，上海财经大学出版社，2012年。

2.施马兰西、威利格：产业组织经济学手册（第1卷），经济科学出版社，2009年。

3.斯蒂芬•马丁：高级产业经济学，上海财经大学出版社，2003年。

4.泰勒尔：产业组织理论，中国人民大学出版社，1997年。

5.夏伊：产业组织理论与应用，清华大学出版社，2005年。

6.卡尔顿、佩洛夫：现代产业组织，中国人民大学出版社，2009年。

7.乔治·J·施蒂格勒：产业组织和政府管制，潘振民译，上海三联书店，1989年。

二、经典外文文献选读（References for Industrial Organization）I. The Theory of the FirmA. Theory1. Tirole, Introduction and The Theory of the Firm.2. Chandler, ''Organizational Capabilities and the Economic History of the Industrial Enterprise,''Journal of Economic Perspectives, 6 (Summer 1992), 79-100.3. R. Coase, ''The Nature of the Firm,'' reprinted in G. Stigler and K. Boulding, eds., Readings in Price Theory, Irwin, 1952, 33 l-351.4. S. Grossman and O. Hart, ''The Costs and Benefits of Ownership: A Theory of Vertical and Lateral Integration," Journal of Political Economy, 94 (August 1986), 691 -796.5. B. Holmstrom and J. Tirole, ''The Theory of the Firm," in HIO.6. B. Klein, R. Crawford, and A. Alchian, ''Vertical Integration, Appropriable Rents, and the Competitive Contracting Process,''Journal of Law and Economics, 21 (October l978), 297-326.7. O. Williamson,The Economic institutions of Capitalism, Free Press, 1985, Chapters 3-6 (especially 1 and 3).B. Empirical Evidence on Asset Specificity1. E. Anderson and D. Schmittlein, ''Integration of the Sales Force: An EmpiricalExamination,"Rand Journal of Economics,15(Autumn 1984), 327-343.2. P. Joskow, ''Vertical Integration and Long Term Contracts: The Case of Coal-Burning Electric-Generating Plants,"Journal of Law, Economics and Organization, I (Spring 1985), 33-80.3. P. Joskow, ''Contract Duration and Relationship-Specific Investments: Empirical Evidence from Coal Markets,"American Economic Review, 77 (March 1987), 168-l85.4. P. Joskow, ''Asset Specificity and the Structure of Vertical Relationships: Empirical Evidence," Chapter 8 in O. Williamson and S. Winter,The Nature of the Firm:Origins, Evolution, and Development,Oxford 1993, 117-137.5. K. Monteverde and D. Teece, ''Supplier Switching Costs and Vertical Integration in the Automobile Industry,''BellJournal of Economics, 13 (Spring 1982), 206-213.6. A. Shepard, "Contractual Form, Retail Pricing and Asset Characteristics in Gasoline Retailing,"Rand Journal of Economics, 24(Spring 1993), 58-77.II. Monopoly PricingA. Basic Monopoly Pricing and Durable Goods1. Tirole, Chapter 1 (including supplementary section).2. M. Pesendorfer, ``Retail Sales. A Study of Pricing Behavior in Supermarkets,'' mimeo.B. First and Third Degree Price Discrimination1. Tirole, Sections 3.0 - 3.22. Katz, M., "The Welfare Effects of Third-Degree Price Discrimination in Intermediate Goods Markets,"American Economic Review, 77, (March 1 987), pp. 154-67.3. Schmalensee, R., ''Output and Welfare Implications of Monopolistic Third-Degree Price-Discrimination,''American Economic Review,71 (March 1981), pp. 242-47.4. Varian, H., ''Price Discrimination and Social Welfare,''American Economic Review, 75 (September 1985), pp. 870-5.5. Perry, Martin, ''Forward Integration by ALCOA: 1888-1930,"Journal of Industrial Economics,29 (l), September 1980, pp. 37-53.C. Second Degree Price Discrimination1. Tirole, Sections 3.3 - 3.5.2. Maskin, E. And J. Riley, "Monopoly with Incomplete Information,"Rand Journal of Economics15 (Summer 1984), pp. 171-96,3. Oi, W., ''A Disneyland Dilemma: Two-Part Tariffs for a Mickey-Mouse Monopoly,''Quarterly Journal of Economics,85 (February 197l), pp. 77-96.4. McAfee, P., J. McMillan, and M. Whinston, ''Multiproduct Monopoly, Commodity Bundling, and Correlation of Values,''Quarterly Journal of Economics, 104 (May 1989), pp. 37l-83.5. Blackstone, E., ''Restrictive Practices in the Marketing of Electrofax Copying Machines. The SCM Corporation Case,''Journal of Industrial Economics, 23 (March 1975), pp. 189-202.6. Shepard, A., ''Price Discrimination and Retail Configuration,''Journal of Political Economy, 99 (February 1991), pp. 30-53.7. I. Ayers, and P. Siegelman, "Race and Gender Discrimination in Bargaining for a New Car,''American Economic Review, 85 (June 1995), 304-321.8. Borenstein, S. and N. Rose, "Competition and Price Dispersion in the U.S. Airline Industry,"Journal of Political Economy, 102 (August 1994), 653-683.III. Estimating Demand (and Supply)1. Deaton and J. Muellbauer,Economics and Consumer Behavior, Parts 1 and2.2. S. Anderson, A. De Palma and J. Thisse,Discrete Choice Theory of Product Differentiation, Chapters 2-5.3. D. Epple, "Hedonic Prices and Implicit Markets: Estimating Demand and Supply Functions for Differentiated Products,Journal of Political Economy, 95 (February 1987), 59-80.4. Berry, S., J. Levinsohn, and A. Pakes, ''Automobile Prices in Market Equilibrium,"Econometrica, Vol. 63, No. 4, July 1995, pp. 841-890.5. A. Petrin, "Quantifying the Benefits of New Products: The Case of the Minivan'', mimeo.6. Goldberg, P.K., ''Product Differentiation and Oligopoly in international Markets: The Case of the U.S. Automobile Industry,''Econometrica, Vol. 63, No. 4, July 1995, pp. 891-952.7. S. Ellison, I. Cockburn, Z. Griliches and J. Hansman, "Characteristics of Demand for Pharmaceutical Products: An Examination of Four Cephalosporins,''Rand Journal of Economics, 28, Autumn 1997, 426-446.8. J. Hausman, "Valuation of New Goods under Perfect and Imperfect Competition,'' inTheEconomics of New Goods, T. Bresnahan and R. Gordon (eds.) and comment by T. Bresnahan.9. J. Hansman, "Reply to Prof. Bresnahan," mimeo.10. T. Bresnahan, "The Apple-Cinnamon Cheerios War: Valuing New Goods, Identifying Market Power, and Economic Measurement," mimeo.IV. Introduction to Strategic Behavior and Static CompetitionA. Introduction to Strategic Behavior1. D. Fudenberg and J. Tirole, ''Noncooperative Game Theory for Industrial Organization: An Introduction and Overview,'' inHIO.2. Tirole, pp. 205-208 and Chapter 11.B. Prices and Output1. C. Shapiro, ''Theories of Oligopoly Behavior," inHIO.2. Tirole, Chapters 2.1 and 5.3. D. Kreps and J. Scheinkman, ''Quantity Precommitment and Bertrand Competition Yield Cournt Outcomes,"BellJournal of Economics,14 (Autumn 1983), 326-337.4. Klemperer, P., "The Competitiveness of Markets with Switching Costs,"Rand Journal of Economics, 18 (Spring 1987), pp. 138-50.5. Sutton, J., and A. Shaked, ''Relaxing Price Competition through Product Differentiation,''Review of Economic Studies,49 (January 1982), pp. 3- 14.6. D. Stalil, "Oligopolistic Pricing with Heterogeneous Consumer Search,''International Journal of Industrial Organization, 14 (April 1996), 243-268.V. Dynamic CompetitionA. Theory1. Tirole, Chapter 6.2. Rotemberg, J. J. and G. Saloner, "A Supergame-Theoretic Model of Price Wars During Booms,''American Economic Review, 76 (June 1986), 390-407.3. K. Bagwell and R. W. Staiger, "Collusion over the Business Cycle,''Rand Journal of Economics, (Spring 1997), 82-106.4. Brock, W. and J. Scheinkman, "Price-Setting Supergames with Capacity Constraints,''Review of Economic Studies, 52 (1985), pp. 37 l-82.5. Green, E. and R. Porter, ''Non-cooperative Collusion Under Imperfect PriceInformation,''Econometrica, 52 (January 1984), pp. 87-100.6. Maskin, E. and J. Tirole, "A Theory of Dynamic Oligopoly II: Price Competition, Kinked Demand Curves, and Edgeworth Cycles,"Econometrica, 56 (May 1988), pp.571 -99.7. Bernheim and M. Whinston, "Multimarket Contact and Collusive Behavior,"Rand Journal of Economics, 21 (Spring 1990), l-26.8. Stigler, G.J., "A Theory of Oligopoly,"Journal of Political Economy, 72 (February l964), pp. 44-61.B. Empirical Evidence1. R. Porter, ''A Study of Cartel Stability: The Joint Economic Committee, 1880-l886,"Bell Journal of Economics, 14 (Autumn 1983), 301-314.2. G. Ellison, ''Theories of Cartel Stability and the Joint Executive Committee,''Rand Journal of Economics, 25 (Spring 1994), 37-57.3. D. Genesove and W. Mullin, "Narrative Evidence on the Dynamics of Collusion: The Sugar Institute Case, " mimeo.4. R. Grether and C. Plott, ''The Effects of Market Practices in Oligopolistic Markets: An Experimental Examination of the Ethyl Case,''Economic inquiry, 22 (October l984), 479-507.5. M. Levenstein, "Price Wars and the Stability of Collusion: A Study of the PreWorld War I Bromine industry,''The Journal of Industrial Economics, June 1997, 117-138.6. S. Borenstein and A. Shepard, ''Dynamic Pricing in Retail Gasoline Markets,''The Rand Journal of Economics, Autumn 1996, Vol. 27, No. 3, pp. 429-451.VI. Empirical Studies of Firm ConductA. Inter-Industry Studies1. F. M. Scherer and D. Ross, Industrial Market Structure and Economic Performance, Chapter 11.2. R. Schmalensee, ''Interindustry Studies of Structure and Performance,'' inHIO.3. Demsetz, H., "Industry Structure, Market Rivalry and Public Policy,''Journal of Law and Economics, 16, (1973), l-10.4. I. Domowitz, R. Hubbard and B. Petersen, "Business Cycles and the Relationship Between Concentration and Price-Cost Margins,"Rand Journal of Economics, 17(Spring 1986), 1-17.5. R. Schmalensee, ''Do Markets Differ Much?"American Economic Review, 75 (June 1985), 341-351.6. M. Salinger, "The Concentration-Margin Relationship Reconsidered,''Brookings Papers on Economic Activity: Microeconomics,1990, 287-335.B. Theory of Conduct Parameters1. T. Bresnahan, "The Oligopoly Solution Concept is Identified,"Economics Letters, 10, 1982, 87-92.2. L. Lau, "On Identifying the Degree of Competitiveness from Industry Price and Output Data,''Economics Letters, 10, 1982, 93-99.3. J. Panzar and J. Rosse, "Testing for 'Monopoly' Equilibrium,"Journal of Industrial Economics, 35 (June 1987), 443-456.4. K. Corts, "Conduct Parameters and the Measurement of Market Power,''Journal of Econometrics???C. Industry-Specific Studies of Firm Conduct1. T. Bresnahan, "Empirical Studies of Industries with Market Power,'' inHIO.2. R. Coterill, "Market Power in the Retail Food Industry: Evidence from Vermont,"Review ofEconomics and Statistics, 68 (August 1986), 379-386.3. A. Nevo, "Measuring Market Power in the Ready-to-Eat Cereal Industry,'' mimeo.4. T. Bresnahan, "Competition and Collusion in the American Automobile Industry: The 1955 Price War,''Journal of Industrial Economics, 35 (June 1987), 457-482.5. D. Genesove and W. Mullin, "Testing Oligopoly Models: Conduct and Cost in the Sugar Industry, 1898-1914,''Rand Journal of Economics,29 (Summer 1 998), 355-377.6. C. Wolfram, "Measuring Duopoly Power in the British Electricity Spot Market,'' mimeo.7. Baker, J. and T. Bresnahan, ''Empirical Methods of Identifying and Measuring Market Power,"Antitrust Law Journal,Vol.61, 1992,pp.3-16.VII. EntryA. Basic Theory1. Tirole, Sections 7.l-7.22. Mankiw, N.G. and M.D. Whinston, "Free Entry and Social Inefficiency,''Rand Journal of Economics,17 (Spring 1986), pp. 48-58.3. Anderson, S., A. de Palma, and Y. Nesterov, "Oligopolistic Competition and the Optimal Provision of Products,"Econometrica, Vol. 63, No. 6, November 1995, pp.l281-1302.4. Sutton, J.,Sunk Costs and Market Structure, MIT Press, 1991, Chapters l-2.5. B. Jovanovic, ''Selection and the Evolution of Industry,"Econometrica, (May 1982), 649-670.6. Banmol, W.K., J.C. Panzar, and R.D. Willig, ''On the Theory of Perfectly Contestable Markets," in J.E. Stiglitz and G.F. Mathewson, eds.,New Developments in the Analysis of Market Structure, MIT Press, 1986.B . Empirical Evidence1. T. Bresnahan and P. Reiss, ''Entry and Competition in Concentrated Markets,'' Journal of Political Economy, 99 (October 1991), 977- 009.2. Comments on Bresnahan and Reiss,Brookings Papers on Economic Activity: Special Issue on Microeconomics, 3 (1987), 872-882.3. T. Dunne, M. Roberts, and L. Samuelson, ''Patterns of Firm Entry and Exit in U.S. Manufacturing,''Rand Journal of Economics, 19 (Winter 1988), 495-515.4. Berry, S. and J. Waldfogel, ''Free Entry and Social Inefficiency in Radio Broadcasting," June 1996.5. S. Berry, ''Estimation of a Model of Entry in the Airline industry, "Econometrica, 60 (July 1992), 889-918.VIII. Strategic InvestmentA. General Considerations1. Tirole, pp. 207-8, Chapter 8.2. J. Bulow, J. Geanakoplos and P. Klemperer, '`Multimarket Oligopoly: Strategic Substitutes and Complements,"Journal of Political Economy,93 (June 1985), 488-511.3. D. Fudenberg and J. Tirole, "The Fat Cat Effect, the Puppy Dog Ploy and the Lean and Hungry Look,''American Economic Review, 74 (May 1 984), 36 1 -366.4. R. Gilbert, ''Mobility Barriers and the Value of Incumbency," inHIO.B. Capacity, Product Differentiation, beaming Curves, Contracts1. A. Dixit, ''The Role of Investment in Entry Deterrence,''Economic Journal, 90 (March l980), 95-106.2. R. Schmalensee, ''Economies of Scale and Barriers to Entry,''Journal of Political Economy, 89(December 1981), pp. 1228-38.3. J.R. Gelman and S.C. Salop, ''Judo Economics. Capacity Limitation and Coupon Competition,''BellJournal of Economics, 14 (Autumn 1983), pp. 315-25.4. D. Fudenberg and J. Tirole, "Capital as a Commitment: Strategic Investment to Deter Mobility,''Journal of Economic Theory,31 (December 1983), 227-250.5. R. Schmalensee, ''Entry Deterrence in the Ready-to-Eat Breakfast Cereal Industry,''BellJournal of Economics, 9 (Autumn 1978), pp. 305-27.6. K. Judd, ''Credible Spatial Preemption,"Rand Journal of Economics,16 (Summer 1985), pp. 153-66.7. D. Fudenberg and J. Tirole, "Learning by Doing and Market Performance,''BellJournal of Economics,14 (Autumn 1983), pp. 522-30.8. P. Aghion and P. Bolton, "Entry Prevention Through Contracts with Customers,''American Economic Review, 77, June 1987, pp. 388-401.9. T.E. Cooper, "Most-Favored Customer Pricing and Tacit Collusion,''Rand Journal of Economics, 17 (Autumn 1986), pp. 377-88.10. J. J. Laffont, P. Rey and J. Tirole, "Network Competition I: Overview and Nondiscriminatory Pricing,''Rand Journal of Economics, 29 (Spring 1 998), l -37.C. Empirical Evidence on Strategic Investment1. J. Chevalier, "Capital Structure and Product Market Competition: Empirical Evidence from the Supermarket Industry,''American Economic Review, June 1995.2. M. Lieberman, "Post Entry investment and Market Structure in the Chemical Processing Industry,"Rand Journal of Economics, 18 (Winter 1987), 533-549.3. G. Hurdle, et al., "Concentration, Potential Entry, and Performance in the Airline Industry,''Journal of Industrial Economics,38 (December 1989), 119-140.4. R. Smiley, "Empirical Evidence on Strategic Entry Deterrence,''International Journal of Industrial Organization, 6 (June 1988), 167- 180.IX. Information and Strategic BehaviorA. Limit Pricing1. Tirole, Sections 9.0 - 9.4.2. P. Milgrom and J. Roberts, ''Limit Pricing and Entry Under Incomplete Information: An Equilibrium Analysis,''Econometrica, 50 (March 1982), 443-460.B. Predation1. Tirole, Sections 9.5 - 9.7.2. P. Milgrom and J. Roberts, ''Predation, Reputation, and Entry Deterrence,"Journal of Economic Theory,27 (August 1982), pp. 288-312.3. G. Saloner, ''Predation, Merger, and Incomplete information,"RandJournal of Economics,18 (Summer 1987), pp. 165-186.4. D. Fudenberg and J. Tirole, ''A 'Signal-Jamming' Theory of Predation,''Rand Journal of Economics, 17 (Autumn 1986), pp. 366-76.5. P. Bolton and D. Scharfstein, ''A Theory of Predation Based on Agency Problems in Financial Contracting,''American Economic Review, 80 (March 1 990), pp. 93- 106.6. Benoit, J.P., ''Financially Constrained Entry in a Game of Incomplete Information,"Rand Journal of Economics,15, pp. 490-99.7. J. Oulover and G. Saloner, ''Predation, Monopolization and Antitrust," inHIO.C. Empirical Studies of Information Asymmetries and Predation1. D. Cooper, S. Garvin and J. Kagel, "Signaling and Adaptive Learning in an Entry Limit Pricing Game,''Rand Journal of Economics, 28 (Winter 1997), 662-683.2. D. Genesove, "Adverse Selection in the Wholesale Used Car Market,''Journal of Political Economy,101 (August 1993), 644-665.3. M. Doyle and C. Snyder, "Information Sharing and Competition in the Motor Vehicle Industry," mimeo.4. T. Hubbard, "Consumer Beliefs and Buyer and Seller Behavior in the Vehicle Inspection Market,'' mimeo.5. J. McGee,'' Predatory Price Cutting The Standard Oil (NJ) Case,''Journal of Law and Economics, l (October 1958), 137-169.6. D. Genesove and W. Mullin, "Predation and Its Rate of Return: The Sugar industry, l887- 1914,"NBER Working Paper6032, 1997.7. D. Weiman and R. Levin, ''Preying for Monopoly: Southern Bell,"Journal of Political Economy,102 (February 1994), 103-26.8. Kadiyali, V., ''Entry, Its Deferrence, and its Accommodation: A Study of the U.S. Photographic Film Industry,"The Rand Journal of Economics, Autumn 1 996, Vol. 27,X. Advertising1. Tirole, Sections2.2-2.4, 7.32. M. Stegeman, ''Advertising in Competitive Markets,''American Economic Review, 81 (March 1991), 210-223.3. F. M. Scherer and D. Ross,Industrial Market Structure and Economic Performance, Chapter 18.4. Kwoka, J. ''Advertising the Price and Quality of Optometric Services,''American Economic Review Papers and Proceedings, 1984, 211 -216.5. P. Ippolito and A. Mathios, ''Information, Advertising and Health: A Study of the Cereal Market,''Rand Journal of Economics,21 (Autumn 1 990), 459-480.6. D. Ackerberg, "Advertising, Learning, and Consumer Choice in Experience Good Markets: An Empirical Examination,'' mimeo.XI. Auctions1. P. McAfee and J. McMillan, ''Auctions and Bidding,"JEL, June 1987, pp. 699-738.2. P. Milgrom, "Auctions and Bidding: A Primer,"JEP, Summer 1989, pp. 3-22.3. K. Hendricks and R. Porter, ''An Empirical Study of an Auction with Asymmetric Information,''American Economic Review, December 1 988, pp. 865-83.4. R. Porter, ''The Role of Information in U.S. Offshore Oil and Gas Lease Auctions,"Econometrica, 63 (January 1995), pp. 1-27.5. R. Porter and D. Zona, "Detection of Bid Rigging in Procurement Auctions,"JPE, June 1993, pp.5 18-38.6. P. Bajari, "Econometrics of the First Price Auction with Asymmetric Bidders," mimeo.7. J.-J. Laffont, H. Ossard, and Q. Vuong, ''Econometrics of First Price Auctions,''EM, July 1995, pp. 953-80.8. J. Kagel, R. Harstad and D. Levin, ''Information Impact and Allocation Rules in Auctions with Affiliated Private Values: A Laboratory Study, "Econometrica, 55 (1987), pp. 1275- 1304.9. J. Kagel, ''Auctions: A Survey of Experimental Research,'' in J. Kagel and A. Roth, eds.,The Handbook of Experimental Economics.XII. Technological ChangeA. Research and Development1. Tirole, Sections 10.l - 10.5, 8. l.32. G. C. Loury, ''Market Structure and Innovation,''Quarterly Journal of Economics, 93 (1979), pp. 395-410.3. D. Fudenberg, R. Gilbert, J. Stiglitz, and J. Tirole, "Preemption, Leapfrogging, and Competition in Patent Races,"European Economic Review, 22 (1983), pp. 3-31.4. D. Fudenberg and J. Tirole, ''Preemption and Rent Equalization in the Adoption of New Technology,''Review of Economic Studies, 52 (1985), pp. 383-401.5. Symposium on Patent Policy,Rand Journal of Economics, 21 (Spring 1990).B. Standardization1. J. Farrell and G. Saloner, "Standardization, Compatibility, and Innovation,''Rand Journal of Economics, 16 (1985), pp. 70-83.2. M. Katz and C. Shapiro, ''Technology Adoption in the Presence of Network Externalities,"Journal of Political Economy, 94 (1986), pp. 822-841.C. Diffusion of Technologies1. Rogers and Shoemaker,The Diffusion of Innovation: A Cross-Cultural Approach, Free Press, 1971.2. G. Ellison and D. Fudenberg, "Rules of Thumb for Social Learning,"Journal of Political Economy, 101 (1993), pp. 612-643.D. Empirical Studies1. A. Pakes, "Patents as Options: Some Estimates of the Value of Holding European Patent Stocks,Econometrica, 54 (July 1986), 755-784.2. M. Trajtenberg, "The Welfare Analysis of Product Innovations with an Application to Computed Tomography Scanners,"Journal of Political Economy, 97 (April 1989), 444-479.3. G. Saloner and A. Shepard, "Adoption of Technologies with Network Effects: An Empirical Examination of the Adoption of Automated Teller Machines,"Rand Journal of Economics, 13 (Autumn 1995), 479-501.4. T. Hubbard, "Why Are Process Monitoring Technologies Valuable? The Use of On-Board Information Technology in the Trucking Industry," mimeo.5. E. Mansfield, "How Rapidly Does New industrial Technology Leak Out?"Journal of Industrial Economics, 34 (December 1985), 217-223.6. N. L. Rose and P. L. Joskow, ''The Diffusion of New Technologies. 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第24卷　第5期2003年 9月　科　研　管　理　Science Research ManagementV ol.24,N o.5Sep,　2003文章编号:1000-2995(2003)05-006-0103论电子商务市场中的“柠檬”问题--理论模型与实践意义潘　勇(中国人民大学商学院,北京　100872)摘要:“柠檬”问题是美国经济学家G eorge Akerlof提出并引入信息经济学的,它主要是研究在传统市场上由于产品质量信息的非对称性及其所造成的结果。

本文构建了电子商务市场上的“柠檬”模型,并依据该模型对电子商务市场中由“柠檬”所产生的对市场效率的影响进行了分析,就电子商务市场中“柠檬”问题的解决途径和将来可能的发展方向进行了讨论。

关键词:“柠檬”问题;阿克洛夫模型;瓦尔拉斯均衡中图分类号:F713.5 文献标识码:A1　引言:“柠檬”问题与“柠檬”模型“柠檬”来源于美国口语对“缺陷车”、“二手车”的经验称呼。

在Akerlof(1970)对“柠檬”市场(旧车市场)进行了经典的分析之后,“柠檬”就成了经济学家对次品或劣质品的比喻说法,而“‘柠檬’问题”指的是在使用这些“柠檬”产品后所产生的、对消费者的不利后果。

“柠檬”理论的主要思想体现在Akerlof教授发表在《经济学季刊》上的经典论文“‘柠檬’市场:质量的不确定性和市场机制”[1]之中。

Akerlof 教授以该模型所具有的广泛而深远的影响力奠定了他在信息经济学中的地位,并摘取了2001年的诺贝尔经济学奖。

该论文主要是分析产品质量与不确定性的关系以及它对市场交易效率的影响。

Akerlof指出,在多数市场环境下,由于买方通常无法观测到个别商品的具体质量,从而买方往往采用市场的平均统计值作为对商品的基本认识。

在这种前提下,根据效用最大化原则,卖方被激励经营低质量的商品以实现收益最大化,其结果交易商品的质量和市场规模都将退化。

Akerlof以严密的数学推导和富有逻辑性的分析证明了自己提出的假说,从而奠定了“柠檬”理论的理论基础。