efficient and durable decision rules with incomplete information we compare six concepts of efficiency for economies with incomplete information depending on the stage at which individuals welfare is evaluated and on whether incentive constraints are recognized an example is shown in which an incentive efficient decision rule may be unanimously rejected by the individuals in the economy we define durable decision rules which can resist such unanimous rejection and show that efficient durable decision rules exist

complementarities multiplicity and supply information if traders can obtain private information about the payoff and the supply of a stock then there can exist i complementarity in information acquisition and ii multiple equilibria in the financial and information markets the additional dimension of supply information increases coordination possibilities in the financial market leading to multiple equilibria the existence of two information sources can lead to information acquisition being complementary the multiplicity of equilibria is suggestive of excess volatility and crashes the different financial market equilibria imply differing patterns of cost of capital and volume of trade 2009 by the european economic association

a class of monotone economies in which rational expectations equilibria exist but prices do not reveal all information abstract some economies having excess demands which depend monotonically on agents information signals are examined if there are no multiple market clearing prices then these economies have strict rational expectations equilibria in which equilibrium prices alone do not transmit all information

marginal pricing and supplement cost allocation in transmission open access the application of marginal costing to transmission pricing in open access schemes requires the collection of a supplement to finance the transmission systems the paper describes the application of marginal cost based pricing in the chilean power system and the difficulties faced in allocating the supplement among parties involved alternative methods for defining the allocation are formulated generalized generation and load distribution factors for cost allocation are formulated and implemented the methods are applied to allocate payments for transmission services provided by the transmission network and by a distribution company

aggregation of information in large cournot markets consider a homogeneous product market where firms have private information about an uncertain demand parameter and compete in quantities we examine the convergence properties of bayesian cournot equilibria as the economy is replicated and conclude that large cournot or almost competitive markets do not aggregate information efficiently except possibly when the production technology exhibits constant returns to scale even in a competitive market there is a welfare loss with respect to the first best outcome due to incomplete information in general nevertheless a competitive market is efficient taking as given the decentralized private information structure of the economy endogenous and costly information acquisition is examined and seen to imply that the market outcome always falls short of the first best level with decreasing returns to scale the results are also shown to be robust to the addition of extra rounds of competition which allows firms to use the information revealed by past prices explicit closed form solutions yielding comparative static results are obtained for models characterized by quadratic payoffs and affine information structures

mechanism design with incomplete information a solution to the implementation problem the main result of this paper is that the multiple equilibrium problem in mechanism design can be avoided in private value models if agents do not use weakly dominated strategies in equilibrium we show that in such settings any incentive compatible allocation can be made the unique equilibrium outcome to a mechanism we derive a general necessary condition for unique implementation which implies that the positive result for private value models applies with considerably less generality to common value settings and to situations in which an agent s information does not index the agent s preferences

rational expectations in microeconomic models an overview abstract this paper is an expository introduction to several topics of current research in the general equilibrium theory of rational expectations more specifically we discuss the existence of exact and approximate rational expectations equilibria the implementation of equilibria the behavior of learning and smoothing processes by which traders construct expectations from repeated observations of the market and the lagged use of the information revealed by prices in an intertemporal sequence of markets the purpose of this discussion is to introduce papers on these topics appearing in the journal of economic theory symposium on rational expectations in microeconomic models

how trading institutions affect financial market performance some laboratory evidence i introduction trading institutions vary considerably across contemporary financial markets 1 but most can be classified into one of two basic types the continuous double auction da allows traders to submit public offers to buy or to sell and to accept other traders offers at any moment in time the double auction institution offers immediacy but non uniform transaction prices the other basic trading institution the clearinghouse ch gathers offers and clears them at a unified price at a pre specified time it sacrifices immediacy for uniform transaction prices 2 the two types of institutions have co existed and evolved for centuries but now are emerging in new electronic versions market participants and policy makers would like to know which institution or variant or combination is most efficient but theoretical and empirical work to date provides little guidance this paper reports on a series of laboratory asset markets experiments designed to compare variants of the double auction and clearinghouse trading institutions the markets are small usually with eight or nine traders but the traders are profit motivated and experienced with the trading institutions the traded asset has uncertain market value and traders receive useful but inconclusive private information they can only learn the asset s true value during the course of trade laboratory markets offer several advantages for empirical study of financial market institutions first private information is observable even controllable in the laboratory and therefore the investigator can directly measure market efficiency 3 second the complexity of the environment can be varied systematically in the laboratory and its effects on market performance can be separated from the effects of the market institution and other forces finally the market institution itself is controllable in the laboratory so it is possible to make valid causal inferences on how the market institution shapes market performance i begin with a survey of relevant literature and other preliminaries in the rest of this section section ii outlines the laboratory procedures the creation of trading environments of varying complexity the electronic implementation of the clearinghouse and double auction trading institutions the computation of theoretical benchmark prices and allocations and the measurement of market performance section iii collects the results following an illustrative account of a double auction trading period and a clearinghouse trading period i use descriptive statistics to summarize market performance in each of the thirty nine experiments the main conclusions are based on statistical comparisons of market performance across alternative market institutions the clearinghouse institution does surprisingly well it delivers greater market depth than the double auction discovers prices at least as efficiently and produces final allocations almost as efficient as the double auction the main institutional variants examined in this paper concern the amount of information made public regarding order placement orderflow the data suggest that public display of the orderflow enhances double auction efficiency but may impair clearinghouse efficiency a study of trading volume shows higher volume in the double auction in both institutions volume increases when important private news arrives and when the trading period is about to end the paper concludes with a brief summary and discussion of the results a companion paper friedman 1991 considers the effects of awarding various privileges to some but not all traders copeland and friedman 1987 1991 provide useful background information on laboratory procedures and computerized double auction markets instructions for the current experiments are available on request the need for empirical work a skeptic might argue that empirical work is unnecessary the mere fact that the double auction and clearinghouse institutions both persist in major financial markets implies that both are highly efficient because a more efficient institution would displace less efficient institutions

security analysis and trading patterns when some investors receive information before others in existing models of information acquisition all informed investors receive their information at the same time this article analyzes trading behavior and equilibrium information acquisition when some investors receive common private information before others the model implies that under some conditions investors will focus only on a subset of securities herding while neglecting other securities with identical exogenous characteristics in addition the model is consistent with empirical correlations that are suggestive of oft cited trading strategies such as profit taking short term position reversal and following the leader mimicking earlier trades in existing models of information acquisition all informed investors receive their information at the same time while these models provide many important insights in reality some investors either fortuitously or owing to superior skill acquire pertinent information before others by being first an investor can exploit this information to great advantage information that is uncovered only slightly later is less valuable even if it has not yet been publicly revealed we show in this article that the sequential nature of information arrival has a significant effect on both the trading decisions and the types of information collected by investors the model we develop describes the investment choices of a set of competitive risk averse investors who investigate the long term prospects of firms lucky or high ability investors uncover the

controlling for the underreporting of remittances empirical studies that use self reported data on remittances to measure the latter s impact on microeconomic incentives mostly ignore the potential errors associated with reporting measurement issues an econometric procedure to control for these errors is developed and applied to household level data from armenia we find evidence of systematic underreporting of remittances after controlling for this we find a strong negative impact of remittances on incentives to work

evaluation of alternatives for power system coordination and pooling in a competitive environment the paper defines and classifies essential issues that relate the need for electric power system coordination with the increasing development of competition principles are formulated and a coordination model and a market structure are proposed emphasizing the need for economic dispatch in the wholesale market a detailed comparison is made of the market and pooling implementations developed in argentina and chile countries that have pioneered the creation of competitive markets in the electric energy sector an evaluation of strengths and weaknesses of those two implementations is included

application of games with incomplete information for pricing electricity in deregulated power pools the authors present a game theory approach to the problem of pricing electricity in deregulated marketplaces they assume that an independent operator receives bids by pool participants and defines transactions among participants by looking for the minimum price that satisfies the demand in the pool the competition among pool participants is modeled as a noncooperative game with incomplete information they assume that each pool participant knows its own operation costs but does not know his opponents operation costs the game with incomplete information is transformed into a game with complete but imperfect information and solved using the nash equilibrium idea the approach presented in this paper is geared towards providing support for pricing electricity in deregulated pools

a note on the importance of overnight information in risk management models this paper examines the economic value of overnight information to users of risk management models in addition to the information revealed by overseas markets that trade during the domestic overnight period this paper exploits information generated via recent innovations in the structure of financial markets in particular certain securities and associated derivative products can now be traded at any time over a 24 h period as such it is now possible to make use of information generated by trading in almost identical securities during the overnight period of the securities that are available over such time periods s p 500 related products are by far the most actively traded and are therefore the subject of this paper using a variety of conditional volatility models that allow time dependent information flow within and across three different s p 500 markets the results show that overnight information flow has a significant impact on the conditional volatility of daytime traded s p 500 securities moreover time consistent forecasts from models that incorporate overnight information are shown to have economic value to risk managers in particular value at risk var models based on these conditional volatility models are shown to be more accurate than var models that ignore overnight information

learning over the business cycle policy implications abstract this paper studies the policy implications of the endogeneity of information about the state of the economy the business cycle can be made less noisy and more efficient by incentivizing firms to vary their pricing and production decisions more with their beliefs about the state of the economy this calls for countercyclical taxes complemented by a monetary policy that leans against the wind the optimal policies trade off allocative efficiency for informational efficiency

equilibrium price formation and the value of private information an economy is analyzed in which agents first choose whether to acquire costly information about the return to a risky asset and then choose demand functions that determine the allocation of assets it is a well known paradox that if agents are price takers and prices are fully revealing then an equilibrium with costly information acquisition does not exist it is shown that if the price formation process is modeled explicitly and agnets are not price takers then it is possible to have an equilibrium with fully revealing prices and costly information acquisition article published by oxford university press on behalf of the society for financial studies in its journal the review of financial studies

the effects of learning on the firm s optimal design quality path abstract the product design decision making process requires the manager to initially set a target value of the design quality dimensions and then through a continuous product development effort adjust these targets to meet the changing needs of the market in this paper we present a control theoretic model with the design quality level as the decision variable under the control of the firm the model captures the effect of learning on production cost the market is assumed to be reactive to both the design quality level of the product and its price optimal decision policies for the design quality path i e the sequence of design quality targets over the product life cycle under a set of functional assumptions are obtained analytically effects of changes in the manufacturing and market conditions e g increase in learning rate cost of providing certain level of quality market sensitivities to quality and price and various pricing strategies are discussed through the results of extensive numerical experimentation

complementarities in organizational design and the diffusion of information technologies an empirical analysis we use a specially designed survey on french firms located in haute savoie to provide empirical evidence suggesting that information and communication technologies adoption is not only influenced by the traditional factors of technology diffusion but also by complementarity effects between strategies organization and information technologies the data collected permitted several advances firstly we could study authentic ict while the recent literature has mainly focused on computer capital stocks or automation tools secondly we constructed measures of the determinants put forward by the models of technology diffusion thirdly we studied three kinds of practices organizational and strategic practices technological choices

another look at the radner stiglitz nonconcavity in the value of information abstract this paper revisits the well known result of r radner and j stiglitz 1984 in bayesian models of economic theory elsevier amsterdam which shows that under certain conditions the value of information exhibits increasing marginal returns over some range their result assumes that both the number of states and the number of signal realizations are finite assumptions which preclude most analyses of optimal information acquisition we provide sufficient conditions that yield this nonconcavity in the value of information in a general framework the role that these conditions play is clarified and illustrated with several examples we also discuss the robustness of the nonconcavity result and the difficulties involved in getting the value of information to be globally concave journal of economic literature classification number d83

unique equilibrium in a model of self fulfilling currency attacks even though self fulfilling currency attacks lead to multiple equilibria when fundamentals are common knowledge we demonstrate the uniqueness of equilibrium when speculators face a small amount of noise in their signals about the fundamentals this unique equilibrium depends not only on the fundamentals but also on financial variables such as the quantity of hot money in circulation and the costs of speculative trading in contrast to multiple equilibrium models our model allows analysis of policy proposals directed at curtailing currency attacks

tail expectation and imperfect competition in limit order book markets abstract perfect competition in liquidity provision in limit order markets is characterized by a tail expectation condition glosten 1994 in this paper we model imperfect competition in schedules by infinitely many liquidity suppliers quoting on a limit order book we show that there are zero rent mixed strategy equilibria featuring finite numbers of active liquidity suppliers none of the equilibria satisfies the competitive outcome not even on average considering a sequence of equilibria with the number of active liquidity suppliers becoming large we show that the aggregate stochastic marginal price schedule converges to the deterministic competitive marginal price schedule

distinguishing panics and information based bank runs welfare and policy implications in this paper we contrast panics and information based bank runs in an effort to provide a robust and empirically plausible model of how bank runs are triggered the model of information based runs is characterized by two sided asymmetric information the bank cannot observe the true liquidity needs of the depositors while depositors are asymmetrically informed about bank asset quality we also examine the relative degrees of risk sharing provided by bank deposit contracts and traded equity contracts we show that the choice of deposit or equity depends on the attributes of and information about the underlying investment returns

trade with heterogeneous prior beliefs and asymmetric information no trade theorems have shown that new information will not lead to trade when agents share the same prior beliefs this paper explores the structure of no trade theorems with heterogeneous prior beliefs it is shown how different notions of efficiency under asymmetric information ex ante interim ex post are related to agents prior beliefs as well as incentive compatible and public versions of those efficiency concepts these efficiency results are used to characterize necessary and sufficient conditions on agents beliefs for no trade theorems in different trading environments

oligopoly models for optimal advertising when production costs obey a learning curve business policy questions frequently involve competitive encounters among several different firms oligopoly theory in economics was devised to answer similar questions but its results so far are largely confined to cases of monopoly one firm duopoly two firms and many firms wheat farmers the cases with n firms where 3 n 10 are of great interest to business policy but are rarely treated in the economics literature because of their extreme difficulty the natural mathematical model for studying such questions is the theory of differential games originally devised by r isaacs isaacs r 1975 differential games robert e krieger publishing co huntington new york originally published by john wiley sons new york 1965 for pursuer evader games later it was extended by j case case j h 1979 economics and the competitive process new york university press new york to nonzero sum differential games for application to questions of economic competition the problem of characterizing an optimal advertising policy over time is an important question in the field of marketing it is especially important during the period of the introduction of a new product and it is also during this time that the production learning curve phenomenon is most pronounced in this paper we study oligopoly models which combine elements of bass s demand growth model bass f m 1969 a new product growth model for consumer durables management sci 15 january 215 227 the vidale wolfe vidale m l h b wolfe 1957 an operations research study of sales response to advertising oper res 5 370 381 and ozga ozga s 1960 imperfect markets through lack of knowledge quart j econom 74 29 52 advertising models with linear or quadratic costs and the production learning curve hirschmann w p 1964 profit from the learning curve harvard bus rev 42 january february 125 139 the boston consulting group 1972 perspectives on experience the boston consulting group boston in the monopoly case n 1 the optimal advertising function is derived by applying green s theorem in the duopoly n 2 and triopoly n 3 cases we use discrete differential game models and find nash equilibrium solutions in each of these models the form of the optimal policy is easy to find but because of the complicated nature of the resulting differential equations closed form solutions for the optimal state and control trajectories are impossible to find hence we use a computer to compute these optimal trajectories and plot them for various parameter settings because 13n parameters must be chosen to define a model with n players a complete search of the parameter space is clearly impossible we content ourselves in this paper with presenting computer plots of four different interesting encounters of the triopoly model our methods can be extended to work just as well for competitive encounters among n players where 1 n 10 we believe that in this paper we have opened up the way to studying oligopoly theory with a small number of participants and under widely varying conditions although the lack of closed form solutions may disappoint some readers we feel that the easy availability of graphical solutions is a more than adequate substitute

the bayesian foundations of solution concepts of games abstract we transform a noncooperative game into a bayesian decision problem for each player where the uncertainty faced by a player is the strategy choices of the other players the priors of other players on the choice of other players the priors over priors and so on we provide a complete characterization between the extent of knowledge about the rationality of players and their ability to successively eliminate strategies which are not best responses this paper therefore provides the informational foundations of iteratively undominated strategies and rationalizable strategic behavior b d bernheim econometrica 52 1984 1007 1028 d pearce econometrica 52 1984 1029 1050 sufficient conditions are also found for nash equilibrium behavior and a result akin to r j aumann econometrica 55 1987 1 18 on correlated equilibria is derived with different hypotheses

optimal electricity supply bidding by markov decision process the bidding decision making problem is studied from a supplier s viewpoint in a spot market environment the decision making problem is formulated as a markov decision process a discrete stochastic optimization method all other suppliers are modeled by their bidding parameters with corresponding probabilities a systematic method is developed to calculate transition probabilities and rewards a simplified market clearing system is also included in the implementation a risk neutral decision maker is assumed the optimal strategy is calculated to maximize the expected reward over a planning horizon simulation cases are used to illustrate the proposed method

mechanism design how to implement social goals existing economic institutions the theorist wants to explain or forecast the economic or social outcomes that these institutions generate but in mechanism design theory the direction of inquiry is reversed we begin by identifying our desired outcome or social goal we then ask whether or not an appropriate institution mecha nism could be designed to attain that goal if the answer is yes then we want to know what form that mechanism might take in this paper i offer a brief introduction to the part of mechanism design called implementation theory which given a social goal characterizes when we can design a mechanism whose predicted

competitive bidding as a control problem the dynamics and mechanisms of bidding by electricity generators to supply electricity to a national grid are investigated a mathematical model for the bidding process is developed and the generators are assumed to act rationally according to the maximize expected utility principle the model and system objectives are interpreted as a classical control problem and results simulated and analytical are presented the results show that by introducing multiple bidding rounds convergence to a pareto optimum is possible if a proportional integral control policy is introduced

policy with dispersed information information regarding economic fundamentals is widely dispersed in society is only imperfectly aggregated through prices or other indicators of aggregate activity and cannot be centralized by the government or any other institution in this paper we seek to identify policies that can improve the decentralized use of such dispersed information without requiring the government to observe this information we show that this can be achieved by appropriately designing the contingency of taxation on ex post public information regarding the realized fundamentals and aggregate activity when information is common as in the ramsey literature or when agents have private information only about idiosyncratic shocks as in the mirrlees literature the contingency on fundamentals alone suffices for efficiency when instead agents have private information about aggregate shocks the contingency on aggregate activity is crucial an appropriate combination of the two contingencies permits the government to i dampen the impact of noise and hence reduce non fundamental volatility without also dampening the impact of fundamentals ii induce agents to internalize informational externalities and hence improve the speed of social learning iii restore a certain form of constrained efficiency in the decentralized use of information and iv guarantee that welfare increases with the provision of any additional information jel c72 d62 d82

risk arbitrage in takeovers this article studies the role of risk arbitrageurs in takeovers and the source of their advantage we show how the presence of arbitrageurs affects the value of the target shares since arbitrageurs are more likely to tender therefore an arbitrageur has the informational advantage of knowing he bought shares in equilibrium the number of arbitrageurs buying shares and the price they pay are determined endogenously we also present several empirical implications including the relationship among trading volume takeover premium liquidity of the shares and the number of risk arbitrageurs investing in one particular deal copyright 2002 oxford university press

timing and quality decisions for entrepreneurial product development abstract an entrepreneur is developing a new product and each period must decide whether to enter the market or to continue development we formulate a model of this decision for ventures facing diminishing returns to product quality and for which funding availability product development success and market competition growth are uncertain we characterize the profit maximizing time to stop product development and enter the market and then show how this stopping time is affected by changes in the business environment by further focussing our modeling assumptions we are able to translate our time based criteria into product quality terms we propose that management set a target quality level that the product must meet in order for the venture to maximize profit we also demonstrate that management should decrease this target and hence the quality of the final product over time and adjust it to respond to changes in the business context

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

optimal response of a thermal unit to an electricity spot market this paper addresses the optimal response of a thermal unit to an electricity spot market the objective is to maximize the unit profit from selling both energy and spinning reserve in the spot market the paper proposes a 0 1 mixed integer linear programming approach that allows a rigorous modeling of i nonconvex and nondifferentiable operating costs ii exponential start up costs iii available spinning reserve taking into account ramp rate restrictions and iv minimum up and down time constraints this approach overcomes the modeling limitations of dynamic programming approaches and is computationally efficient results from realistic case studies are reported

does society benefit from investor overconfidence in the ability of financial market experts abstract this paper develops a securities market model in which participants beliefs diverge and prices are monotonic in beliefs relative to rational expectations i e correct and unanimous beliefs overconfidence among uninformed traders about the precision of experts information leads to pareto superior equilibria efficiency enhancing departures from rational expectations occur over a dense subset of parameter space but only for one configuration of beliefs uninformed traders must be more confident than informed experts overconfidence in the form of excessive trust in the predictive ability of experts sets off a virtuous cycle of increased trading that improves liquidity and reduces transaction costs for everyone

an exploration of the eductive justifications of the rational expectations hypothesis this paper examines justifications of the rational expectations hypothesis that rely on the analysis of the agents mental forecasting educing activity which involves forecasting the forecasts of others etc the corresponding concept of eductive learning stability based on the game theoretical concept of rationalizability is primarily used within the classical muth model conditions for coordination of beliefs are interpreted and discussed they are robust to the introduction of noise more generally eductive stability fits economic intuition on coordination stability increases when the industry product differentiation increases and when decisions are sequential and observable copyright 1992 by american economic association

endogenous public information and welfare in market games this paper performs a welfare analysis of markets with private information in which agents can condition on noisy prices in the rational expectations tradition pricecontingent strategies introduce two externalities in the use of private information a payoff pecuniary externality related to aggregate volatility and a learning externality the impact of the first depends on whether competition is of the strategic substitutes or complements variety and the second induces agents to put too little weight on private information we find that with strategic substitutes and when the learning externality is not very strong agents put too much weight on private information and prices are too informative this will happen in the normal case where the allocational role of price prevails over its informational role under strategic complementarity there is always under reliance on private information the welfare loss at the market solution may be increasing in the precision of private information the analysis provides insights into optimal business cycle policy and a rationale for a tobin like tax for speculators in financial markets

transaction analysis in deregulated power systems using game theory the electric power industry is in transition to a deregulated marketplace for power transactions in this environment all power transactions are made based on price rather than cost a regional power pool is noted as the most straightforward path to a deregulated electricity marketplace however many questions remain unanswered regarding the economics of power pool participation in a deregulated energy marketplace participants are interested in maximizing their own profits regardless of the system wide profits it is perceived that competition will reduce the price of electricity for retail customers however the key issue for participants is related with the price definition to remain competitive in this paper the authors use game theory to simulate the decision making process for defining offered prices in a deregulated environment the outcome of this study may be used by power pool coordinators to discourage unfair coalitions a modified ieee 30 bus power system is used as a deregulated power pool to illustrate the main features of the proposed method

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

market liquidity hedging and crashes in the absence of significant news hedging strategies were blamed for the stock market crash of october 1987 but traditional models cannot explain how a relatively small amount of selling could cause so large a price drop the authors develop a rational expectations model in which prices play an important role in shaping expectations markets are much less liquid in their model than in traditional models discontinuities or crashes can occur even with relatively little hedging the model is consistent with theories as disparate as keynes beauty contest insights and thom s catastrophe analysis and suggests means to reduce volatility copyright 1990 by american economic association

nodal uniform or zonal pricing distribution of economic surplus competitive markets for electricity determine either a uniform marginal price ump a set of nodal marginal prices nmps or a smaller set of zonal marginal prices zmps in theory the nmp system is best as it correctly accounts for transmission constraints and losses in some versions but critics allege that the large number of prices is confusing since the ump or zmp solution must be adjusted to account for transmission constraints and losses it is reasonable to consider a market design in which actual dispatch corresponds to an nmp model that accounts for losses and if a ump or zmp model is used at all it is only to compute prices for settlements and compensation for constrained on or off generation or load we prove that if used in this way the ump or zmp models a do not affect the total economic surplus b redistribute the surplus among generators and loads at the different nodes and c give perverse incentives for generation expansion we illustrate on a realistic system

information trade and derivative securities hellwig s 1980 model is used to analyze the value of improving trading opportunities by more frequent trading in the underlying asset or by trading in a derivative asset with multiple trading sessions uninformed investors behave as rational trend followers while more informed investors follow a contrarian strategy as trading becomes continuous pareto efficiency is achieved with trading in an appropriate derivative security pareto efficiency may be achieved in only a single round of trading all derivative claims are then priced on black and scholes 1973 principles and in the absence of further supply shocks no trading will take place in subsequent trading rounds article published by oxford university press on behalf of the society for financial studies in its journal the review of financial studies

marginal pricing of transmission services a comparative analysis of network cost allocation methods a strict marginal network pricing policy is not able to generate enough revenues to recover the cost of the primary transmission service other related network services are ignored here this cost recovery problem requires the stipulation of a complementary charge which completes the network marginal revenues this paper evaluates numerically and qualitatively three different allocation methods of the complementary charge marginal participation factors mean participation factors and benefit factors the evaluation has been applied to the spanish electrical system model

risk assessment in energy trading this paper provides a state of the art summary of risk assessment in energy trading techniques from financial engineering are needed by electric energy companies to manage price risk these tools are needed by suppliers distributors and traders in a competitive electric power marketplace tools that have been adapted to the specific environment of the electric power system include portfolio analysis and hedging instruments this paper provides a comprehensive critical literature survey of what has been applied to date in the power markets and which areas continue to need additional research one example market scenario is used throughout the paper to demonstrate the usefulness of the risk assessment methods

risk aversion market liquidity and price efficiency a model of a noncompetitive speculative market is analyzed in which privately informed traders and market makers are risk averse market liquidity is found to be nonmonotonic in the number of informed traders their degree of risk aversion and the precision of their information it is also shown that increased liquidity trading leads to reduced price efficiency and that under endogenous information acquisition market liquidity may also be nonmonotonic in the variance of liquidity trades article published by oxford university press on behalf of the society for financial studies in its journal the review of financial studies

efficient use of information and social value of information this paper analyzes equilibrium and welfare for a tractable class of economies games that have externalities strategic complementarity or substitutability and heterogeneous information first we characterize the equilibrium use of information complementarity heightens the sensitivity of equilibrium actions to public information raising aggregate volatility whereas substitutability heightens the sensitivity to private information raising cross sectional dispersion next we define and characterize an efficiency benchmark designed to address whether the equilibrium use of information is optimal from a social perspective the efficient use of information reflects the social value of aligning choices across agents finally we examine the comparative statics of equilibrium welfare with respect to the information structure the social value of information is best understood by classifying economies according to the inefficiency if any in the equilibrium use of information we conclude with a few applications including production externalities beauty contests business cycles and large cournot and bertrand games

a decentralized market with common values uncertainty non steady states we analyse a market where i trade proceeds by random and anonymous pairwise meetings with bargaining ii agents are asymmetrically informed about the value of the traded good and iii no new entrants are allowed once the market is open we show that information revelation and efficiency never obtain in equilibrium even as discounting is removed this holds whether the asymmetry is two sided or one sided in some cases there exist equilibria where a substantial amount goes untraded this contrasts with the earlier literature which was based on the steadystate equilibria of a model where agents enter the market every period

de stabilizing speculation on futures markets an alternative view point abstract this paper offers a new interpretation for possible destabilizing effects of opening futures markets in our model adapted from stein 1987 speculation on futures markets reduces the likelihood of occurrence of a rational expectations equilibrium although the equilibrium price is less volatile after the futures market is opened which is usually viewed as a stabilizing effect traders may find it more difficult or even impossible to coordinate their expectations in order to implement this equilibrium

market plurality and manipulation performance comparison of independent system operators in this paper the authors present three different models that represent the coordinating functions of existing independent system operators isos and discuss their advantages and disadvantages max iso is a centralized operator based on the pool model and min iso is a decentralized operator based on the bilateral model mix iso is positioned in between having multiple power exchanges or bilateral contracts the performance of the different isos is compared by the total social welfare and the vulnerability to market manipulation a numerical example is presented to compare the performance of different isos the max iso is considered to be the most efficient model theoretically but it does not necessarily provide the best market in terms of vulnerability to market manipulation

benefit optimization of centralized and decentralized power systems in a multi utility environment the objective is to examine the theoretical bases for benefit optimization in centralized and decentralized electric power systems in a centralized single control power system cost revenue and profit are used as system performance criteria for benefit optimization and the conditions are compared the results show that conventional cost minimization is not necessarily equivalent to benefit optimization based on other criteria in a decentralized multi utility power system benefit optimization and its allocation are investigated at the unconstrained economic optimum economic optimum with constraints and conditions under which the solution is an economic suboptimum the data from the epri regional systems are used to show practical examples of the benefit allocation with wheeling transactions although some rules are better for society than others there still is not one right answer to determine the rules for benefit optimization

airline traffic and urban economic development this paper provides new evidence on the link between airline traffic and employment in us metropolitan areas the evidence confirms the common view that good airline service is an important factor in urban economic development frequent service to a variety of destinations reflected in a high level of passenger enplanements facilitates easy face to face contact with businesses in other cities attracting new firms to the metro area and stimulating employment at established enterprises the empirical results show that a 10 per cent increase in passenger enplanements in a metro area leads approximately to a 1 per cent increase in employment in service related industries however airline traffic has no effect on manufacturing and other goods related employment suggesting that air travel is less important for such firms than for service related businesses these estimates are generated controlling for reverse causality between employment and traffic the results imply that expansion of chicago s o hare ai

do prices transmit rationally expected information a simple model with asymmetric information in which inventory holders or traders submit demand curves to an auctioneer has a unique partially revealing equilibrium we wonder whether the agents can plausibly coordinate on this equilibrium through eductive reasoning relying on common knowledge the analysis stresses the role of two effects sensitivity and amplification whose product should be small enough the property is obtained whenever the equilibrium excess demand is steep enough i e when the search for information does not distort demand too much neither the influence of the number of informed agents nor that of noise trading are monotonic real time learning has strikingly different features jel d82 d84

an introduction to the theory of rational expectations under asymmetric information every good economics textbook contains the cliche that market prices provide signals which facilitate the allocation of resources to their best use in a world not subject to random shocks consumers and producers when faced with competitive prices need look no further than their own preferences or production technology to be able to make a decision they need give no thought to the tastes endowments or technology of other agents however in a world subject to random shocks this is no longer the case agents are faced with the problem of forecasting future states of nature and more importantly of forecasting the impact of these states on the actions of other agents rational expectations theories provide a model of how agents make those forecasts in a world subject to random shocks it will be the case that agents acquire or at least attempt to acquire information about the future realization of the shocks it will in general be the case that different agents have access to different information the fact that information is dispersed throughout the economy has the potential to cause a misallocation of resources relative to what would be the case if all agents knew everything an efficient allocation of resources will in general require the transfer of information from consumers who have some information about their future demands to producers who can take current actions to mitigate avoidable scarcities or surpluses though many classical and neo classical writers emphasize the informational role of prices the standard marshallian or walrasian model of competitive equilibrium does not involve prices transferring information across traders the purpose of this paper is to show that rational expectations models are radically different from walrasian models in an economy where traders have diverse information this is demonstrated by showing that unlike what occurs in a walrasian equilibrium of an economy with heterogeneous information if there is a complete set of insurance markets and utility is additively separable over time then there exists a rational expectations equilibrium which gives consumers the same allocation as if each consumer has access to all of the economy s information this implies that under the above assumptions a central planner with all the economy s information could not pareto dominate the competitive allocation achieved when traders have diverse information and rational expectations this paper makes no attempt to survey the literature on rational expectations the reader is referred to shiller 1978 barro 1981 for a survey of macroeconomics and rational expectations and radner 1980 for a survey of the microeconomics and mathematical theory of rational expectations this paper will however try to outline the evolution of the rational expectations concept from a notion of optimal forecasting to a virtually complete departure from the walrasian model of equilibrium the rest of this section is devoted to a discussion of pre rational expectations ideas

viable allocations of information in financial markets abstract we study in the context of a financial market allocations of information that are consistent with endogenous information acquisition we focus on whether information is concentrated within a fraction of the market or is diffuse the aggregation of information in prices tends to make signals more complementary than they would be if considered in isolation favoring concentration of information however the ability to use some signals together with prices to predict other signals may increase the degree of substitutability among signals we present conditions under which each of these effects is particularly strong

a simulation model for a competitive generation market the simulation of a wholesale electricity market should go beyond a simple optimization based on the operating costs of the generating units a model of a competitive electricity market must consider the market structure the strategy of the market participants and any other factor that lead to prices different from costs this paper presents cosmee a model of a wholesale electricity market based on simple bids that estimates expected bid prices and quantities system hourly prices and generation schedules taking into account the bidding strategies of generators and the structure of the market the model reflects the profit maximizing behavior of the market agents subject to different types of constraints cosmee has been used to simulate a real wholesale market

price volatility without news about fundamentals abstract in a pseudo dynamic model financial prices can exhibit chaotic volatility even when there is no fluctuation in economic fundamentals the source of the volatility is some speculative trading rule

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

effects of insider trading disclosures on speculative activity and future prices this paper explores a simple model of the effects of requiring a public disclosure of insider trader activity in future markets

on the existence of rational expectations equilibrium abstract we prove a theorem on the existence of rational expectations general economic equilibrium when agents condition on prices as well as on private information and maximize the expectation of a state dependent utility function the key to the result is a new idealization of what it means for a set of empirical distributions to support agents expectations this idealization depends on the notion that agents compare their expectations with continuous versions of the random empirical distributions that are generated by the workings of the economy the existence theorem covers all strictly concave utility functions arbitrary distributions of the state variable and situations in which the dimension of the state variable is large relative to the number of commodities

informed speculation with imperfect competition competitive rational expectations models have the unsatisfactory property dubbed the schizophrenia problem by hellwig that each trader takes the equilibrium price as given despite the fact that he influences that price an examination of information aggregation in a non competitive rational expectations model using a nash equilibrium in demand functions shows that the schizophrenia problem is avoided by having each trader take into account the effect his demand has on the equilibrium price given a distribution of private information across traders prices reveal less information than in the competition equilibrium and prices no longer become fully informative in the limit as noise trading vanishes or as traders become risk neutral with small traders the model may become one of monopolistic competition not perfect competition in contrast to the competitive model a reasonable model of endogenous acquisition of costly private information is obtained even when traders are risk neutral

partially revealing rational expectations equilibrium in a competitive economy abstract a class of pure exchange economies is considered in which some agents are informed of private information and others are uninformed existence of a partially revealing rational expectations equilibrium ree is proved without restricting attention to particular functional forms for utility functions and probability distributions without introducing noise into the model and without departing from the standard definition of ree the equilibrium is robust in the sense that if the primitives of the economy are slightly perturbed the economy continues to have a qualitatively similar ree with somewhat stronger assumptions placed on the economy the equilibrium is also the unique measurable ree

information aggregation in a noisy rational expectations economy abstract this paper analyzes a general equilibrium model of a competitive security market in which traders possess independent pieces of information about the return of a risky asset each trader conditions his estimate of the return both on his own private source of information and price which in equilibrium serves as a noisy aggregator of the total information observed by all traders a closed form characterization of the rational expectations equilibrium is presented a counter example to the existence of fully revealing equilibrium is developed