monotone equilibrium in multi unit auctions in two sided multi unit auctions having a variety of payment rules including uniform price and discriminatory auctions a monotone pure strategy equilibrium mpse exists when bidders are risk neutral with independent multi dimensional types and interdependent values in fact all mixed strategy equilibria are ex post allocation and interim expected payment equivalent to mpse thus for standard expected surplus revenue analysis there is no loss restricting attention to monotone strategies

efficient non contractible investments in large economies abstract do investors making complementary investments face the correct incentives especially when they cannot contract with each other prior to their decisions we present a two sided matching model in which buyers and sellers make investments prior to matching once matched buyer and seller bargain over the price taking into account outside options efficient decisions can always be sustained in equilibrium we characterize the inefficiencies that can arise in equilibrium and show that equilibria will be constrained efficient we also show that the degree of diversity in a large market has implications for the extent of any inefficiency journal of economic literature classification numbers c78 d41 d51

convergence to efficiency in a simple market with incomplete information a model of trade with m buyers and m sellers is considered in which price is set to equate revealed demand and supply in a bayesian nash equilibrium each trader acts not as a price taker but instead misrepresents his true demand supply to influence price in his favor this causes inefficiency we show that in any equilibrium the amount by which a trader misreports is o 1 m and the corresponding inefficiency is o 1 m2 the indeterminacy and the inefficiency that is caused by the traders bargaining behavior in small markets thus rapidly vanishes as the market increases in size

two dimensional efficiency decomposition to measure the demand effect in productivity analysis this paper proposes a two dimensional efficiency decomposition 2ded of profitability for a production system to account for the demand effect observed in productivity analysis the first dimension identifies four components of efficiency capacity design demand generation operations and demand consumption using network data envelopment analysis network dea the second dimension decomposes the efficiency measures and integrates them into a profitability efficiency framework thus each component s profitability change can be analyzed based on technical efficiency change scale efficiency change and allocative efficiency change an empirical study based on data from 2006 to 2008 for the us airline industry finds that the regress of productivity is mainly caused by a demand fluctuation in 2007 2008 rather than technical regression in production capabilities

existence of equilibrium in single and double private value auctions we show existence of equilibria in distributional strategies for a wide class of private value auctions including the first general existence result for double auctions the set of equilibria is invariant to the tie breaking rule the model incorporates multiple unit demands all standard pricing rules reserve prices entry costs and stochastic demand and supply valuations can be correlated and asymmetrically distributed for double auctions we show further that at least one equilibrium involves a positive volume of trade the existence proof establishes new connections among existence techniques for discontinuous bayesian games

efficiency and information aggregation in large uniform price auctions abstract we prove that the equilibria of a large interdependent value uniform price auction model where bidders have arbitrary preferences for multiple units can be approximated by a nonatomic exchange economy we show that the uniform price auction is approximately efficient with a large number of participants and asymptotically aggregates idiosyncratic bidder information into the market price more generally our analysis framework provides conditions justifying the use of nonatomic limit model approximations to analyze the large market behavior of game theoretic models we demonstrate continuity requirements on the economic primitives sufficient for the equilibrium strategies of the two models to converge as the number of participants in the finite game approaches infinity

optimality versus practicality in market design a comparison of two double auctions we consider a market for indivisible items with m buyers and m sellers traders privately know their values costs which are statistically dependent two mechanisms are considered the buyer s bid double auction collects bids and asks from traders and determines the allocation by selecting a market clearing price it fails to achieve all possible gains from trade because of strategic bidding the designed mechanism is a revelation mechanism in which honest reporting of values costs is incentive compatible and all gains from trade are achieved this optimality however comes at the expense of plausibility i the monetary transfers among the traders are defined in terms of the traders beliefs about each other s value cost ii a trader may suffer a loss ex post iii the mechanism may run a surplus deficit ex post we compare the virtues of the simple yet mildly inefficient buyer s bid double auction to the flawed yet perfectly efficient designed mechanism

the effects of statistically dependent values on equilibrium strategies of bilateral k double auctions abstract this paper describes how introducing statistical dependency among trader values changes the equilibrium bidding strategies in bilateral k double auctions and uses the special case of affiliation to illustrate the range of equilibrium responses to a change in the value distribution consistent with standard intuition a change from independent to strictly affiliated valuations can result in high value buyers and low value sellers bidding closer to their actual values while low value buyers and high value sellers distort their bids farther from their true values however there also exist equilibria for which either type of trader responds to a change in the distribution of values in the opposite direction whether a given trader bids more aggressively or less aggressively can also be non monotonic with respect to the trader s value

investments holdup and the form of market contracts the authors analyze incomplete contracts to induce efficient investment with exogenous switching costs fixed price contracts are efficient generate some rigidity in prices are renegotiated intermittently by possibly small amounts and when inflation is positive generate asymmetric responses to shocks all consistent with evidence on prices and wages with two sided specific investments efficiency requires prices to have sufficient escalator clauses to avoid renegotiation as observed in many long term contracts a third case with one sided specific investments can generate take or pay contracts and explain why firms sometimes pay for specific investments that appear to benefit employees directly

unforeseen contingencies and incomplete contracts we scrutinize the conceptual framework commonly used in the incomplete contract literature this literature usually assumes that contractual incompleteness is due to the transaction costs of describing or of even foreseeing the possible states of nature in advance we argue however that such transaction costs need not interfere with optimal contracting i e transaction costs need not be relevant provided that agents can probabilistically forecast their possible future payoffs even if other aspects of the state of the nature cannot be forecast in other words all that is required for optimality is that agents be able to perform dynamic programming an assumption always invoked by the incomplete contract literature the foregoing optimality result holds very generally provided that parties can commit themselves not to renegotiate moreover we point out that renegotiation may be hard to reconcile with a framework that otherwise presumes perfect rationality however even if renegotiation is allowed the result still remains valid provided that parties are risk averse

the dynamic in stability of backwards induction abstract the evolutionary basis for predicting the backwards induction solution in finite extensive form games with perfect information is examined evolution is modelled using the replicator dynamic in combination with rare perturbations that introduce a small change in the proportion of each strategy the criterion for our judgement is whether this dynamic stabilizes over time at the subgame perfect equilibrium outcome we find that the backwards induction solution is fully justified by this process only in very simple games examples of more complex games are given in which this process does not select between the subgame perfect equilibrium outcome and alternative nash equilibrium outcomes journal of economic literature classification numbers c72 c79

why sunk costs matter for bargaining outcomes an evolutionary approach abstract two bargaining parties play the nash demand game to share a pie whose size is determined by one party s investment decision various investment levels are subgame perfect adding the investment decision to young s evolutionary bargaining model yields the following long run outcome efficient investment prevails and the investor s share of the pie approximates die maximum of i the smallest share that induces efficient investment even if the investor expects to appropriate the available pie from every inefficient investment and ii half of the pie the result favors forward induction to subgame consistency and equity theory to hold ups journal of economic literature classification numbers c78 l14

auctions actions and the failure of information aggregation we study a market where k identical and indivisible objects are allocated using a uniform price auction where n k bidders each demand one object before the auction each bidder receives an informative but imperfect signal about the state of the world the good that is auctioned is a common value object for the bidders and a bidder s valuation for the object is determined jointly by the state of the world and an action that he chooses after winning the object but before he observes the state we show that there are equilibria where the auction price is completely uninformative about the state of the world and aggregates no information even in an arbitrarily large auction in the equilibrium that we construct because prices do not aggregate information agents have strict incentives to acquire costly information before they participate in the market also market statistics other than price such as the amount of rationing and bid distributions contain extra information about the state our findings sharply contrast with past work which shows that large auctions aggregate information when there is no ex post action

adjustment dynamics and rational play in games when a given strategic situation arises repeatedly the possibility arises that equilibrium predictions can be justified by a dynamic adjustment process we examine myopic adjustment dynamics a class that includes replicator dynamics from evolutionary game theory simple models of imitation models of experimentation and adjustment and some simple learning dynamics we present a series of theorems showing conditions under which behavior that is asymptotically stable under some such dynamic is strategically stable in the sense of kohlberg and mertens this behavior is thus as if the agents in the economy satisfied the extremely stringent assumptions that game theory traditionally makes about rationality and beliefs journal of economic literature classification number c72

implementation in differential information economies abstract we consider the problem of implementation of social choice correspondences in differential information economies we provide necessary conditions for implementation and slightly stronger conditions which are sufficient to guarantee implementation

competitive rational expectations equilibria without apology abstract consider a financial market with n risk averse asymmetrically informed traders when n grows at the same rate as noise trading prices in competitive and in strategic rational expectations equilibrium converge to each other at a rate of 1 n equilibria in the two scenarios are close when noise trading volume per informed trader is large in relation to risk bearing capacity both equilibria converge to the competitive equilibrium of a limit continuum economy as the market becomes large at a slower rate of 1 n the results extend to endogenous information acquisition and the connections with the grossman stiglitz paradox are highlighted

on the possibility of informationally efficient markets this paper presents conditions for a resolution of the grossman stiglitz paradox of informationally efficient markets we display a market with asymmetric information where a privately revealing equilibrium obtains in a competitive framework and where incentives to acquire information are preserved as long as the correlation in traders valuations is not too large the equilibrium is efficient and the problems associated with fully revealing rational expectations equilibria are precluded without resorting necessarily to noise traders the robustness of the results to general information structures is established and the effect of market power is examined in a large market approximation to the competitive economy the model is applied to explain changes in bidding behavior in central bank liquidity auctions in the crisis period jel d82 d84 g14 e59

property rights and investments an evolutionary approach abstract when contracts are not enforceable or property rights are not clearly defined individuals may lack an incentive to carry out costly investments even when they are socially efficient some recent contributions such as ellingsen and robles 2002 prove that this problem may be less dramatic than standard economic models would suggest they propose evolutionary models in which only efficient equilibria can be stochastically stable in this paper we show that these results are not robust with respect to the introduction of individual heterogeneity when individuals have different cost functions stochastically stable states may be inefficient even when they induce a positive suboptimal level of investment

stability in large matching markets with complementarities labor markets can often be viewed as many to one matching markets it is well known that if complementarities are present in such markets a stable matching may not exist we study large random matching markets with couples we introduce a new matching algorithm and show that if the number of couples grows slower than the size of the market a stable matching will be found with high probability if however the number of couples grows at a linear rate with constant probability not depending on the market size no stable matching exists our results explain data from the market for psychology interns

the rate of convergence to efficiency in the buyer s bid double auction as the market becomes large a trader who privately knows his preferences may misrepresent them in order to influence the market price this strategic behaviour may prevent realization of all gains from trade in this paper trade in a simple market with an explicit rule for price formation is modelled as a bayesian game we show that the difference between a trader s bid and his reservation value is maximally 0 1 m where m is the number of traders on each side of the market competitive pressure as m increases thus quickly overcomes the inefficiency private information causes and f ces the market towards an efficient allocation

existence of equilibrium in large double auctions abstract we show the existence of a pure strategy symmetric increasing equilibrium in double auction markets with correlated conditionally independent private values and many participants the equilibrium we find is arbitrarily close to fully revealing as the market size grows our results provide strategic foundations for price taking behavior in large markets

the optimality of a simple market mechanism strategic behavior in a finite market can cause inefficiency in the allocation and market mechanisms differ in how successfully they limit this inefficiency a method for ranking algorithms in computer science is adapted here to rank market mechanisms according to how quickly inefficiency diminishes as the size of the market increases it is shown that trade at a single market clearing price in the k double auction is worst case asymptotic optimal among all plausible mechanisms evaluating mechanisms in their least favorable trading environments for each possible size of the market the k double auction is shown to force the worst case inefficiency to zero at the fastest possible rate

an evolutionary model of bargaining abstract individuals from two populations of bargainers are randomly matched to play the nash demand game they make their demands by choosing best replies based on an incomplete knowledge of the precedents and occasionally they choose randomly there is no common knowledge over the long run typically one division will be observed almost all of the time this stochastically stable division is close to the nash solution when all agents in the same population are alike when the populations are heterogeneous a generalization of the nash solution results if there is some mixing between the two populations the stable division is fifty fifty journal of economic literature classification number c78

the efficiency of competitive mechanisms under private information we consider the efficiency properties of exchange economies where privately informed traders behave strategically specifically a competitive mechanism is any mapping of traders reports about their types to an equilibrium price vector and allocation of the reported economy in our model some traders may have non vanishing impact on prices and allocations regardless of the size of the economy although truthful reporting by all traders cannot be achieved we show that given any desired level of approximation there is n such that any bayesian nash equilibrium of any competitive mechanism of any private information economy with n or more traders leads with high probability to prices and allocations that are close to a competitive equilibrium of the true economy in particular allocations are approximately efficient a key assumption is that there is small probability that traders behave non strategically

the rate of convergence to perfect competition of matching and bargaining mechanisms abstract we study the steady state of a market with incoming cohorts of buyers and sellers who are matched pairwise and bargain under private information a friction parameter is the length of the time period until the next meeting we provide a necessary and sufficient condition for the convergence of mechanism outcomes to perfect competition at the linear rate in which is shown to be the fastest possible among all bargaining mechanisms the condition requires that buyers and sellers always retain some bargaining power the bargaining mechanisms that satisfy this condition are called nonvanishing bargaining power nbp mechanisms simple random proposer take it or leave it protocols are nbp while k double auctions k da are not we find that k das have equilibria that converge to perfect competition at a linear rate converge at a slower rate or even do not converge at all

the loser s curse and information aggregation in common value auctions we consider an auction in which k identical objects of unknown value are auctioned off to n bidders the k highest bidders get an object and pay the k 1st bid bidders receive a signal that provides information about the value of the object we characterize the unique symmetric equilibrium of this auction we then consider a sequence of auctions a r with n r bidders and k r objects we show that price converges in probability to the true value of the object if and only if both k r and n r k r i e both the number of objects and the number of bidders who do not receive an object go to infinity

dynamic matching two sided incomplete information and participation costs existence and convergence to perfect competition consider a decentralized dynamic market with an infinite horizon and participation costs in which both buyers and sellers have private information concerning their values for the indivisible traded good time is discrete each period has length and each unit of time continuums of new buyers and sellers consider entry traders whose expected utility is negative choose not to enter within a period each buyer is matched anonymously with a seller and each seller is matched with zero one or more buyers every seller runs a first price auction with a reservation price and if trade occurs both the seller and the winning buyer exit the market with their realized utility traders who fail to trade continue in the market to be rematched we characterize the steady state equilibria that are perfect bayesian we show that as converges to zero equilibrium prices at which trades occur converge to the walrasian price and the realized allocations converge to the competitive allocation we also show the existence of equilibria for sufficiently small provided the discount rate is small relative to the participation

financial regulatory reform after the crisis an assessment this is a survey of progress with the postcrisis global g20 reform of the financial system in five key areas of new regulation 1 making financial institutions more resilient 2 ending too big to fail 3 making derivatives markets safer 4 transforming shadow banking and 5 improving trade competition and market transparency the resiliency reforms particularly bank capital regulations have been increasingly successful in improving financial stability but have been accompanied by some reduction in secondary market liquidity i review specific areas where reforms are far from complete or have even been counterproductive this paper was accepted by gustavo manso finance conflict of interest statement the author s webpage at http www stanford edu duffie provides related research and disclosure of potential conflicts of interest

the red queen in action the longitudinal effects of capital investments in the mobile telecommunications sector organizations undertake capital investments in technology to generate revenues or decrease costs and thereby enhance profitability however red queen type responses by competing organizations in the form of rapid imitation and escalating of technology investments erode the ability of the investing organizations to sustain gains in profitability productivity gains from these investments may persist but they may not translate into sustained profitability gains owing to declining prices brought about by a hypercompetitive environment the emergence and erosion of benefits attributable to capital investments is examined by decomposing profitability into productivity price recovery product mix and capacity utilization and by regressing each performance measure on past technology investments a polynomial distributed lag model is estimated with quarterly data for 30 firms in the mobile telecommunications services sector from 1996 to 2005 the results indicate that capital investments are positively associated with productivity of current and future periods and their association with profitability is only positive in the future after six quarters these results highlight a unique outcome of the red queen hypothesis simply by imitating learning and investing in technology due to competition is beneficial to all firms in the industry

cooperative investments and the value of contracting recent articles have shown that contracts can support the efficient outcome for bilateral trade even in the face of specific investments and incomplete contracting these studies typically considered selfish investments that benefit the investor e g the seller s investment reduces her production costs the authors find very different results for cooperative investments that directly benefit the investor s partner e g the seller s investment improves the buyer s value of the good most importantly if committing not to renegotiate the contract is impossible then contracting has no value i e the parties cannot do better than to abandon contracting altogether in favor of ex post negotiation

efficiency of large private value auctions we consider discriminatory and uniform price auctions for multiple identical units of a good players have private values possibly asymmetrically distributed and for multiple units our setting allows for aggregate uncertainty about demand and supply in this setting equlibria generally will be inefficient despite this we show that such auctions become arbitrarily close to efficient if they are large and use this to derive an asymptotic characterization of revenue and bidding behavior

bargaining under incomplete information this paper presents and analyzes a bargaining model of bilateral monopoly under uncertainty under the bargaining rule proposed the buyer and the seller each submit sealed offers that determine whether the good in question is sold and the transfer price the nash equilibrium solution of this bargaining game implies an offer strategy of each party that is monotonic in its own reservation price and depends on its assessment of the opponent s reservation price issues of relative bargaining advantage and efficiency are examined for a number of special cases finally we discuss the appropriateness of the nash solution concept

the essentiality of money in environments with centralized trade abstract lagos and wright 2005 introduced an influential model of monetary exchange in which trade alternates between centralized and decentralized markets and money is essential a limitation of their model and of the literature that follows is that they do not provide a microfoundation for the process of exchange in the centralized market in this paper we show that how one models exchange in the centralized market matters for the essentiality of money by describing the centralized market as a strategic market game and studying conditions under which money is essential

do people play nash equilibrium lessons from evolutionary game theory evolutionary game theory provides an answer to two of the central questions in economic modeling when is it reasonable to assume that people are rational and when is it reasonable to assume that behavior is part of a nash equilibrium and if it is reasonable which equilibrium the traditional answers are not compelling and much of evolutionary modeling is motivated by the need for a better answer evolutionary game theory suggests that in a range of settings agents do eventually play a nash equilibrium moreover evolutionary modeling has shed light on the relative plausibility of different nash equilibria

rationalizable strategic behavior the notion of equilibrium proposed by nash 19 has come to play a dominant role in economic applications of noncooperative games while analyses of nash equilibria have unquestionably contributed to our understanding of economic behavior it would be unreasonably optimistic to maintain that nash solved the problem of noncooperative strategic choice there is a small literature beginning with ellsberg 6 and a much larger oral tradition which argues that nash behavior is neither a necessary consequence of rationality nor a reasonable empirical proposition in this paper i take the view that although there may be various reasons why an agent might select a nash strategy the notion of an equilibrium has little intrinsic appeal within a strategic context when an agent reaches a decision in ignorance of the strategies adopted by other players rationality consists of making a choice which is justifiable by an internally consistent system of beliefs rather than one which is optimal post hoc this point of view is not original indeed most serious justifications of the nash hypothesis embrace such an approach arguing that agents will expect the game to yield a nash outcome and consequently will choose their equilibrium strategies nevertheless when we think in terms of maximizing utility subject to expectations rather than realizations it becomes clear that the nash hypothesis far from being a consequence of rationality arises from certain restrictions on agents expectations which may or may not be plausible depending upon the game being played we are then quite naturally led to ask are there any restrictions of individuals expectations and hence choices which are required by rationality alone rather than by subjective plausibility this paper is concerned with defining justifying characterizing and refining a criterion for rational strategic choice which i label rationalizability

evolution of beliefs and the nash equilibrium of normal form games abstract the paper formulates a simple two person model of learning with pattern recognition and discusses its implications in particular it focuses on the asymptotic behavior of players beliefs when the game has a mixed strategy nash equilibrium journal of economics literatureclassification numbers c72 d83

an experimental study of the holdout problem in a multilateral bargaining game abstract when an economic exchange requires agreement by multiple independent parties the potential exists for an individual to strategically delay agreement in an attempt to capture a greater share of the surplus created by the exchange this holdout problem is a common feature of the land assembly literature because development frequently requires the assembly of multiple parcels of land we use experimental methods to examine holdout behavior in a laboratory bargaining game that involves multi person groups complementary exchanges and holdout externalities the results of six treatments that vary the bargaining institution number of bargaining periods and the cost of delay demonstrate that holdout is common across institutions and is on average a payoff improving strategy for responders both proposers and responders take a more aggressive initial bargaining stance in multi period bargaining treatments relative to single period treatments but take a less aggressive bargaining stance when delay is costly nearly all exchanges eventually occur in our multi period treatments leading to higher overall efficiency relative to the single period treatments both with and without delay costs

radial and non radial decompositions of profit change with an application to indian banking abstract grifell tatje and lovell grifell tatje e lovell c a k 1999 profits and productivity management science 45 1177 1193 made significant contributions to the literature on the extended radial dea framework by decomposing profit change into six mutually exclusive components their approach however poses two basic problems first the radial estimates on these components might give conflicting signals about the direction of profit change after the full radial efficiencies are achieved when slacks are present second evaluations of these components using base period prices as weights can be potentially misleading to address these concerns we first introduce non radial dea models and then provide a few strong theoretical arguments in favor of using as weights either current period prices or an average price covering both periods to value the contributions of each of these components the indian banking sector is taken as a case study to illustrate the radial and non radial decompositions of profit change so as to empirically examine the role of competition on profit change and its drivers our broad empirical results are as follows first radial and non radial models yield diametrically opposite results on the contributions of various components second the increasing efficiency change trends in all ownership groups after 2002 indicate that the government reform process instituted on the banking industry has had a favorable effect on the performance of the indian banking sector third despite the fact that nationalized banks are the oldest banks their output and resource allocation behaviors do not reflect their learning experience

toward a strategic foundation for rational expectations equilibrium a step toward a strategic foundation for rational expectations equilibrium is taken by considering a double auction with n buyers and m sellers with interdependent values and affiliated private information if there are sufficiently many buyers and sellers and their bids are restricted to a sufficiently fine discrete set of prices then generically there is an equilibrium in nondecreasing bidding functions that is arbitrarily close to the unique fully revealing rational expectations equilibrium of the limit market with unrestricted bids and a continuum of agents in particular the large double auction equilibrium is almost efficient and almost fully aggregates the agents information

does evolution solve the hold up problem abstract the paper examines the theoretical foundations of the hold up problem at the first stage one agent decides on the level of a relationship specific investment there is no contract so at the second stage the agent must bargain with a trading partner over the surplus that the investment has generated we show that the conventional underinvestment result hinges crucially both on the assumed bargaining game and on the choice of equilibrium concept in particular we prove the following two results i if bargaining proceeds according to the nash demand game any investment level is subgame perfect but only a particular efficient outcome is stochastically stable ii if bargaining proceeds according to the ultimatum game with the trading partner as proposer only the minimal investment level is subgame perfect but any investment level is stochastically stable journal of economic literature classification numbers l14 c78

on the failure of monotonicity in uniform price auctions except for well studied special cases in which bidders have single unit demand or bidders are risk neutral with independent private values equilibria of uniform price auctions with private values need not possess familiar monotonicity properties in particular equilibria in weakly undominated strategies may exist in which some bidders bid strictly less on some units when they have strictly higher values for every unit

markups in double auction markets abstract we study the continuous double auction cda market with simulated traders using three simple markup rules relative to analytic results obtained for markups in the simpler call market cm we find that uniform cda markups have a more complex and non monotonic impact on cda market outcomes such as price volume and efficiency the symmetric nash equilibrium markup in the cda is remarkably close to the most efficient markup in thick markets which may partially explain the mysterious efficiency for cda market

procurement and renegotiation parties bound by an incomplete contract have an incentive to renegotiate after acquiring new information the issue of the parties investment in the relationship before renegotiation is analyzed in a simple two period procurement model the firm invests in the first period it then learns its production cost and the sponsor learns its value for the project williamson s underinvestment presumption is shown to hold under very general assumptions about bargaining and about the ex post asymmetry of information as long as the firm s investment is not observable by the sponsor the introduction of a cancellation fee may well lead to even less investment contrary to what is sometimes argued the role of ex ante price fixing as an alternative way to reintroduce some form of commitment and the problem of cost overruns are discussed last it is shown that if investment is observable by the sponsor andthus may become a joint decision variable the two parties may choose to under or overinvest

equilibria existence and characterization in auctions achievements and open questions establishing existence and characterizing equilibria is a fundamental step in the study of auctions theoretical characterizations and empirical predictions are well accepted only to the extent that they are based on equilibria however despite the fact that auctions have been extensively studied there are still many problems regarding equilibrium existence and characterization waiting for resolution in this survey we review the landmark results and highlight open questions in addition we review the standard assumptions underlying these results and discuss the suitability of the nash equilibrium solution concept we focus our review on single object auctions but also review results in multi unit divisible combinatorial and double auctions

rationalizable strategic behavior and the problem of perfection this paper explores the fundamental problem of what can be inferred about the outcome of a noncooperative game from the rationality of the players and from the information they possess the answer is summarized in a solution concept called rationalizability strategy profiles that are rationalizable are not always nash equilibria conversely the information in an extensive form game often allows certain unreasonable nash equilibria to be excluded from the set of rationalizable profiles a stronger form of rationalizability is appropriate if players are known to be not merely rational but also cautious what constitutes rational behavior in a noncooperative strategic situation this paper explores the issue in the context of a wide class of finite noncooperative games in extensive form the traditional answer relies heavily upon the idea of nash equilibrium nash 17 the position developed here however is that as a criterion for judging a profile of strategies to be reasonable choices for players in a game the nash equilibrium property is neither necessary nor sufficient some nash equilibria are intuitively unreasonable and not all reasonable strategy profiles are nash equilibria the fact that a nash equilibrium can be intuitively unattractive is well known the equilibrium may be imperfect introduced into the literature by selten 20 the idea of imperfect equilibria has prompted game theorists to search for a narrower definition of equilibrium while this research some of which will be discussed here has been extremely instructive it remains inconclusive theorists often agree about what should happen in particular games but to capture this intuition in a general solution concept has proved to be very difficult if this paper is successful it should make some progress in that direction the other side of the coin has received less scrutiny can all non nash profiles really be excluded on logical grounds i believe not the standard justifications for considering only nash profiles are circular in nature or make gratuitous assumptions about players decision criteria or beliefs the following discussion of these points is extremely brief due to space constraints more detailed arguments may be found in pearce 18

internet auctions with many traders abstract we study a multi unit auction environment similar to ebay sellers each with a single unit of a homogeneous good set reserve prices at their own second price auctions each buyer has private value for the good and wishes to acquire a single unit buyers can bid as often as they like and move between auctions we characterize a perfect bayesian equilibrium for this decentralized dynamic mechanism in which conditional on reserve prices an efficient set of trades occurs at a uniform price in a large but finite market the sellers set reserve prices equal to their true costs under a very mild distributional assumption so ex post efficiency is achieved buyers strategies in this equilibrium are simple and do not depend on their beliefs about other buyers valuations or the number of buyers and sellers

profit productivity and price differential an international performance comparison of the natural gas transportation industry the objective of this paper is to evaluate the performance of natural gas transportation utilities focusing on the three key strategic performance measures of profit productivity and price differential we propose a methodology that expresses the three performance measures in a unified single equation using the edgeworth index the proposed methodology is applied to an international comparison of the performance of 28 natural gas transportation utilities operating in eight countries in which the business environments differ greatly the empirical results show the possible causes of performance differences and may shed some light on the direction of regulatory policy especially for developing countries that have relatively short histories in the natural gas industry such as korea

cycles of learning in the centipede game abstract this paper studies the evolutionary properties of the centipede game for this game the use of backward induction as a model of rational behavior has been consistently challenged by the experimental evidence our claim is that backward induction can still accurately predict the players behavior provided that they are given time enough to appreciate the strategic environment in which they operate we support this claim by proving convergence to the backward induction solution for all continuous time monotonic selection dynamics however we also show that this solution is intrinsically unstable and how this instability is positively related to the length of the game journal of economic literature classification numbers c72 c79

interdependencies between transport fuel demand efficiency and quality an application to austria abstract this paper focuses on the interdependencies between technical efficiencies and energy demand which are often either treated in isolation or do not get the sufficient attention in the literature more precisely this paper uses technical efficiencies as one crucial determinant of energy demand in order to integrate at least two issues that are usually investigated separately from each other the rebound effect resulting from improved technical efficiencies and the asymmetry of energy demand in this regard our paper sets out a theoretical framework which has the following implications higher efficiency increases service demand first order rebound low fuel prices and higher efficiency increases the demand for quality second order which in turn increases service demand further third order ceteris paribus energy price shocks should increase scrapping rates fuel prices direct the rd those on engine efficiency are irreversible which has the consequence that energy price elasticities depend on the history of energy prices rather than being asymmetrical derived implications are subsequently tested on austrian data in particular the purchasing decision diesel versus gasoline powered cars allows to refute the myth that consumers apply high implicit rates for discounting the future benefit from efficient cars

pivotal players and the characterization of influence a player s influence relative to a mechanism and opponents strategies is the maximum difference his action can make in the expected value of a collective outcome a player is pivotal if his influence exceeds a threshold we provide tight bounds on the number of pivotal players and on average influence these bounds are uniform over all mechanisms and action profiles and are achieved at mechanisms that take the form of a majority rule we illustrate our analysis with an example of provision of a public good where each individual compares the private cost of his contribution with its influence on the collective outcome journal of economic literature classification numbers d62 d89 h41

convergence to perfect competition of a dynamic matching and bargaining market with two sided incomplete information and exogenous exit rate abstract consider a decentralized dynamic market with an infinite horizon and incomplete information in which buyers and sellers values for the traded good are private and independently drawn time is discrete each period has length and each unit of time a large number of new buyers and sellers enter the market within a period each buyer is matched with a seller and each seller is matched with zero one or more buyers every seller runs a first price auction with a reservation price and if trade occurs the seller and winning buyer exit with their realized utility traders who fail to trade either continue in the market to be rematched or exit at an exogenous rate we show that in all steady state perfect bayesian equilibria as approaches zero equilibrium prices converge to the walrasian price and realized allocations converge to the competitive allocation

a framework for analyzing changes in strategic performance in this paper we present a framework for analyzing changes in strategic performance traditional measures for comparing the strategic performance across firms or over time have been return on investment roi and its component ratio return on sales ros we decompose the ros ratio into four separate ratios that capture the impact of changes in a firm s productivity price recovery product mix and capacity utilization on its profitability these ratios help to highlight the micro sources of strategic success or failure they can be used to assess changes in the performance of a firm compared to itself over time or to other firms in its industry group this framework can also be used to evaluate changes in the dynamic performance of an industry as a whole we illustrate the use of these ratios with a 4 year analysis of the performance of a large manufacturing company we also demonstrate how the technique can be applied to an industry with an evaluation of the performance of u s telecommunications firms between 1975 and 1987 a period during which the industry experienced a progressive increase in competitive pressure

learning and price discovery in a search market we introduce learning into an otherwise standard two sided search and bargaining market there is uncertainty about the price distribution due to uncertainty about an underlying exogenous state of relative demand in the high state buyers are on the long side otherwise they are on the short side in equilibrium prices are on average higher in the high state individual agents learn about the distribution while searching agents typically start out by experimenting with a tough bargaining position buyers may initially insist on a low price and sellers on a high price after successive failures to trade agents become increasingly pessimistic about the market conditions and soften their bargaining stance when frictions are small equilibrium transaction prices are approximately market clearing despite aggregate demand being unknown thus the search and bargaining procedure enables price discovery in a decentralized market

hold up and the evolution of investment and bargaining norms abstract the purpose of this paper is to explore the evolution of bargaining norms in a simple production problem with two sided relationship specific investments and competition the puzzle we wish to address is why efficient bargaining norms do not evolve even though there exist efficient sequential equilibria conditions under which stochastically stable bargaining conventions exist are characterized and it is shown that there is a hierarchy of norms with a stochastically stable division rule that is independent of the long run investment strategy due to this independence efficient sequential equilibria are not in general stochastically stable this result may help us understand why institutions such as firms may be needed to ensure efficient relationship specific investments

social stability and equilibrium in the field of noncooperative game theory nash equilibrium nash 1951 has played a central role as a solution concept in bold strokes one may discern two major interpretations of nash equilibrium in the context of rational players the first which is close to the eductive interpretation of binmore 1987 1988 and the complete information interpretation of kaneko 1987 assumes that the game is played exactly once if it is a repeated game the repetition occurs once and the players have sufficient knowledge and ability to analyze the game in a rational manner sometimes it is assumed that all players have consistent hierarchies of beliefs where the game and their priors are common knowledge bayesian interpretation such as proposed by aumann 1987 advanced this idea to the level that the players have a common prior from this point of view however nash equilibrium seems far from being satisfactory

evolutionary stability with equilibrium entrants abstract the strategy that upsets a potential evolutionarily stable strategy may in itself be very unstable or may differ from the candidate strategy only in irrelevant ways this paper develops a solution concept addressing these difficulties we lood for a set of nash equilibria such that small groups of entrants whose members are satisfied with their entry cannot take the population out of the set such a set is robust to the iterated removal of weakly dominated strategies depends only on the reduced normal form and has the never a weak best response property for generic two person extensive form games such sets generate payoffs consistent with proper equilibria

modularity and greed in double auctions abstract designing double auctions is a complex problem especially when there are restrictions on the sets of buyers and sellers that may trade with one another the goal of this paper is to develop a modular approach to the design of double auctions by relating it to the exhaustively studied problem of designing one sided mechanisms with a single seller or alternatively a single buyer we consider several desirable properties of a double auction feasibility dominant strategy incentive compatibility the still stronger incentive constraints offered by a deferred acceptance implementation exact and approximate welfare maximization and budget balance for each of these properties we identify sufficient conditions on two one sided algorithms one for ranking the buyers one for ranking the sellers and on a method for their composition into trading pairs which guarantee the desired property of the double auction our framework also offers new insights into classic double auction designs such as the vcg and mcafee auctions with unit demand buyers and unit supply sellers

college assignment as a large contest abstract we develop a model of college assignment as a large contest wherein students with heterogeneous learning costs compete for seats at vertically differentiated colleges through the acquisition of productive human capital we use a continuum model to approximate the outcomes of a game with large but finite sets of colleges and students the continuum approximation lends tractability to a rich model for studying investment incentives in rank order competitions by incorporating two common families of affirmative action mechanisms into our model admissions preferences and quotas we can show that legal admissions preference schemes and illegal quotas have the same sets of equilibria including identical outcomes and investment strategies

an evolutionary approach to pre play communication we add a round of pre play communication to a finite two player game played by a population of players pre play communication is cheap talk in the sense that it does not directly enter the payoffs the paper characterizes the set of strategies that are stable with respect to a stochastic dynamic adaptive process periodically players have an opportunity to change their strategy with a strategy that is more successful against the current population any strategy that weakly improves upon the current poorest performer in the population enters with positive probability when there is no conflict of interest between the players only the efficient outcome is stable with respect to these dynamics for general games the set of stable payoffs is typically large every efficient payoff recurs infinitely often

evolutionary dynamics with aggregate shocks abstract we study the evolution of the continuous time replicator dynamics when payoffs are subject to aggregate shocks that take the form of a wiener process in the absence of mutation the system need not have an ergodic distribution with mutation the system does have an ergodic distribution in the limit as the mutation rate and the variance of the shocks converge to zero this distribution concentrates on the risk dominant equilibrium this result is not however robust to changes in the underlying deterministic dynamics

incentives in the probabilistic serial mechanism abstract the probabilistic serial mechanism bogomolnaia and moulin 2001 9 is ordinally efficient but not strategy proof we study incentives in the probabilistic serial mechanism for large assignment problems we establish that for a fixed set of object types and an agent with a given expected utility function if there are sufficiently many copies of each object type then reporting ordinal preferences truthfully is a weakly dominant strategy for the agent regardless of the number of other agents and their preferences the non manipulability and the ordinal efficiency of the probabilistic serial mechanism support its implementation instead of random serial dictatorship in large assignment problems

bilateral matching and bargaining with private information we study equilibria of a dynamic matching and bargaining game dmbg with two sided private information bilateral bargaining the model is a private information replica of mortensen and wright 2002 there are two kinds of frictions time

do traders strategically time their pledges during real world walrasian auctions abstract experimental research suggests the walrasian t tonnement auction encourages traders to under reveal preferences even encouraging initial pledges contrary to true desires because pledges are not binding we analyze the timing and characteristics of individual pledges and trades during 9604 auctions for redbeans conducted by the tokyo grain exchange we find no evidence of contrarian pledging and little evidence of under revelation as many traders over reveal as under reveal most traders pledge seriously from the beginning despite the considerable heterogeneity in pledging behavior across individual traders these differences appear to have no relationship with traders profits nor do they appear to affect the achievement of equilibrium

cheap talk coordination and evolutionary stability abstract asymmetric information games where the informed player can send a costless message sender receiver games typically have equilibria where meaningful communication occurs we therefore know such cheap talk can matter still even when there is no conflict of interest there are also equilibria where no information transmission occurs this paper shows that for a class of games with perfectly coinciding interests modeled as asymmetric contests where players are unsure of which role they will have only meaningful communication is evolutionarily stable journal of economic literature classification numbers c70 c72 d82

asymmetric information bargaining problems with many agents a yes or no decision must be made about some issue all agents must agree the coase theorem asserts that the efficient outcome will always result suppose the value positive or negative that an individual attaches to an affirmative decision is privately known to that individual it is proved under very mild conditions that with independent types as the number of agents increases the probability of an affirmative efficient decision goes to zero an example in which it is common knowledge that an affirmative decision is efficient and yet the probability of such a decision goes to zero is given

information aggregation in a large multi stage market game abstract a three stage market game mechanism is devised that is simple actions are quantities and outcomes are determined by arithmetic operations that do not depend on details of the economy and achieves efficiency in a two divisible good pure exchange setting with potential information aggregation after an entry stage agents make offers which are provisional for all but a small randomly selected group then those offers are announced and everyone else makes new offers with payoffs determined by a shapley shubik market game for a finite and large number of players there exists an almost ex post efficient equilibrium conditions for uniqueness are also provided

manufacturing strategy and competitiveness the importance of manufacturing strategy ms has never been questioned and has been emphasized in many theoretical concepts frameworks and models there are only a few empirical studies however which examine whether these theories work in practice in this paper the hypothesis that the existence of ms contributes to company level competitiveness ros inventory turnover is tested the study is based on international data which were collected in the second round of the international manufacturing strategy survey the database contains more than 700 companies from the machinery industry isic 381 385 from 23 countries the results partially support the hypothesis the existence of ms seems to have a positive effect on ros however it does not have any relation to inventory turnover r 2002 elsevier science b v all rights reserved

informational size and incentive compatibility we examine a general equilibrium model with asymmetrically informed agents the presence of asymmetric information generally presents a conflict between incentive com patibility and pareto efficiency we present a notion of informational size and show that the conflict between incentive compatibility and efficiency can be made arbitrarily small if agents are of sufficiently small informational size the incompatibility of pareto efficiency and incentive compatibility is a central theme in economics and game theory the issues associated with this incompatibility are particularly important in the design of resource allocation mechanisms in the presence of asymmetrically informed agents where the need to acquire information from agents in order to compute efficient outcomes and the incentives agents have to misrepresent that information for personal gain come into conflict despite a large literature that focuses on these issues there has been little work aimed at understanding those situations in which informational asymmetries are quantitatively important virtually every transaction is characterized by some asymmetry of information any investor who buys or sells a share of stock generally knows something rel evant to the value of the share that is not known to the person on the other side of the transaction in order to focus on more salient aspects of the problem many models rightly ignore the incentive problems associated with informa tional asymmetries in the belief that for the problem at hand agents are infor mationally small however few researchers have investigated the circumstances under which an analysis that ignores these incentive problems will yield results similar to those obtained when these problems are fully accounted for in this paper we study a class of mechanism design problems our goal is to formalize informational size in a way that when agents are informationally small 1 early versions of this paper circulated under the titles informational smallness and pareto effi ciency and informational smallness and incentive compatibility we thank jacques cremer dean foster andreu mas colell stephen morris david schmeidler and particularly faruk gul for help ful conversations and rajiv vohra for a very careful reading we also thank the numerous partici pants in seminars at which this paper was presented for helpful comments we also thank an editor and the referees for very helpful comments and thank ichiro obara for pointing out an error in an earlier version postlewaite gratefully acknowledges support from the national science foundation

bidding strategies in oligopolistic dynamic electricity double sided auctions in this paper the problem of developing bidding strategies in oligopolistic dynamic electricity double sided auctions is studied we model electricity double sided auctions as dynamic systems and use nash cournot strategies for the market participants generating firms and load serving entities through simulation studies we compare the efficiency and competitiveness of electricity double sided auctions to those of electricity supplier only auctions using the developed bidding strategies

efficient equilibrium selection in evolutionary games with random matching abstract this paper investigates the sensitivity of recent evolutionary models of learning to the specification of the matching mechanism we study a literally random matching mechanism combined with a process of strategy adjustment based on the realized average performance of each strategy in the key class of symmetric 2 2 coordination games the pareto efficient equilibrium per se is selected rather than the risk dominant equilibrium as the probability of experimentation or mutation goes to zero furthermore convergence to the equilibrium is relatively fast we extend these results for example to games of common interest journal of economic literature classification numbers c72 c73

the rate at which a simple market converges to efficiency as the number of traders increases an asymptotic result for optimal trading mechanisms private information in an independent private values market provides incentives to traders to manipulate equilibrium prices strategically this strategic behavior precludes ex post efficient market performance increasing the number of traders improves the efficiency of some trading mechanisms by enabling them to better utilize the private information traders bids and offers reveal this paper shows that the expected inefficiency of optimally designed mechanisms relative to ex post efficient allocations decreases almost quadratically as the number of traders increases

efficiency of large double auctions we consider large double auctions with private values values need be neither symmetric nor independent multiple units may be owned or desired participation may be stochastic we introduce a very mild notion of a little independence we prove that all nontrivial equilibria of auctions that satisfy this notion are asymptotically efficient for any alpha 0 inefficiency disappears at rate 1 n 2 alpha