financial innovation and information the role of derivatives when a market for information exists we study the effects of financial innovation in a model of endogenous information acquisition we determine the conditions under which the introduction of a derivative written on an existing stock increases or decreases the incentive to purchase information we show that financial innovation produces some effects which hold across informational structures and others which differ the former coincide with the few empirical results that are robust in the literature effects on prices risk premia and volatility while the latter coincide with the ones that differ experiment by experiment effects on volume correlation between volume and volatility and market informational efficiency copyright 2002 oxford university press

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

strategic pricing signalling and costly information acquisition abstract consider a market where an informed monopolist sets the price for a good or asset with a value unknown to potential buyers upon observing the price buyers may pay some cost for information about the value before deciding on purchases under a belief restriction which generalizes the idea of the cho kreps intuitive criterion we establish a version of the grossman stiglitz paradox there is no separating equilibrium with fully revealing prices yet we also resolve the paradox there is a unique equilibrium and as the cost of information becomes small the equilibrium approaches the full information outcome and prices become perfectly revealing

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

rational expectations equilibrium an alternative approach we study a dynamic market process in which traders condition their beliefs about payoff relevant parameters on past endogenously generated market data and current exogenous data we say that a market process is informative if the beliefs of traders who receive only endogenously generated market data converge almost surely to the true parameter value our main result is that under standard regularity hypotheses the generic market process is informative we define an equilibrium as the limit points of the market process journal of economic literature classification numbers 02 1 026 c 1984 academic press inc

time varying risk premia volatility and technical trading rule profits evidence from foreign currency futures markets abstract this paper re examines the efficiency of foreign currency futures markets by evaluating the role of time varying risk premia and volatility in explaining technical trading rule profits the results show that large parts of the technical rule profits can be explained by the time varying risk premia estimated from a general model for the conditional capm the bootstrap distributions for the profits under the null model average one third to one half of the actual profits and enclose the actual profits well within the 90 confidence intervals time varying conditional volatility explains an additional 10 of the profits

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

endogenous participation risk in speculative markets abstract this paper analyses the dynamic implications of an asset pricing model with incomplete participation due to entry costs it is shown that heterogeneity in entry costs can lead to the existence of multiple stochastic sunspot equilibria whereby the number of agents in the market and asset prices fluctuate endogeneously over time in the absence of fundamental uncertainty such asset price fluctuations occur despite the uniqueness of the deterministic equilibrium and thus bear no link to the usual notion of steady state indeterminacy in addition to excess volatility the equilibria exhibit predictable and conditionally heteroskedastic returns

the value of information in risky markets discussion the three papers in this session illustrate well the breadth of the challenge posed to economists by the study of risk and information the theoretical research is filled with paradoxes and we are just now understanding existence uniqueness and stability of equilibria in these models research in these areas is quite difficult but also exciting in many respects information is what economic theory is all about once the fiction of complete arrowdebreu markets is dropped the applied economist faces additional problems of practical definition measurement and data thus empirical work is lagging significantly behind the theory the authors of these papers are to be applauded for collectively demonstrating both how far we have come and how much work there remains for the rest of us buccola s paper addresses fundamental issues of the efficiency of decentralized markets under risk he makes a good point that for full efficiency to hold two conditions are required markets must exhibit weak informational efficiency and the equilibrium price must be given by the competitive equilibrium i focus on the second condition with durable assets the relevant concept is an intertemporal competitive equilibrium path we know from the macroeconomic and capital theory literatures that it is perfectly possible for markets to incorporate available information and for spot markets to clear at each date yet for the economy to be on an inefficient path that does not converge to equilibrium in the long run the dynamic competitive equilibrium is even harder to compute than the static one this undermines the relevance of laboratory experiments this is closely related to the idea of a speculative bubble in which an asset s price does not equal its market fundamental and diverges farther from it over time rational expectations does not necessarily rule this out diba and grossman blanchard and watson where it does it eliminates this ki d of inefficiency by assuming that agents always act so that transversality conditions hold i can think of no very believable reason for this continuously to be so has the market for agricultural land a market not considered by buccola been subject recently to such a bubble and crash

underreaction to fundamental information and asymmetry in mispricing between bullish and bearish markets an experimental study abstract in contrast to existing literature we implement experimental asset markets with fluctuating fundamental values following a stochastic process therefore we can measure traders behavior in both bullish and bearish markets we observe underreaction of price changes to changes in fundamental value which induces overvaluation in bearish and undervaluation in bullish markets we also find an asymmetry between markets with bullish fundamental values and those with bearish ones as the former markets show a higher degree of informational efficiency the reason for the observed underreaction lies in the relatively large volatility of the underlying fundamental value process

the effect of the time structure of information on the expectational stability of rational expectations abstract the boundedly rational learning of rational expectations may not lead to equilibria with strong informational properties the anomaly arises for certain parameterizations that a market of well informed agents where current price enters its own conditioning information set may be at a disadvantage in learning rational expectations compared with a market of agents who can only condition on past prices

boom bust dynamics in a stock market participation model with heterogeneous traders abstract the boundedly rational heterogeneous agent literature can be considered to have properly started with a number of contributions in the early 90s with the impressive contribution by carl chiarella who amongst his huge field of research developed several milestone models of heterogeneous interacting agents that are able to generate a number of dynamic outcomes compatible with the empirical evidence in this paper we propose a stock market model in which participation depends upon an attractiveness measure related to the market activity and the fundamental value of the market a market maker adjusts the stock price with respect to the current endogenous excess market demand which in turn depends on the demands of the different types of agents populating the economy market participants are also allowed to switch between different strategies analytical and numerical results confirm how the participation mechanism amplifies the occurrence of endogenous booms and busts in line with empirical and experimental evidence

reflections of david teece s profiting from technological innovation abstract this paper builds on teece s 1986 paper to consider how appropriability conditions affect the ability of an industry and the economy as a whole to progress in particular it offers a careful discussion of the broader costs and benefits of patenting can too much appropriability actually work against the broader interests of society in fostering economic growth and technical advance in the market

self organization and the persistence of noise in financial markets abstract a dynamic model of financial markets with learning is demonstrated to produce a self organized system that displays critical behavior the price contains private information that traders learn to extract and employ to forecast future value since the price reflects the beliefs of the traders the learning process is self referencing as the market learns to correctly extract information from the price the market deemphasizes private information despite the convergence of the model towards the parameters producing efficiency pricing deviations remain constant due to the increased sensitivity of the price to small errors in information extraction produced by the model s own convergence

on aggregation of information in competitive markets the dynamic case abstract this article examines in the spirit of hellwig 1980 how a dynamic competitive security market aggregates and communicates information between various market participants at every instant it employs a continuous time economy consisting of a large number of heterogeneous agents who are endowed with noisy private signals about the risky asset payoff of differing precision it yields a stationary rational expectations equilibrium in which at every instant the agents use information contained in the market prices without rendering their private information redundant it shows that the market price reflects only that part of private information which is common to many signals and thus extends hellwig s single period results to a multi period model

j shaped returns to timing advantage in access to information experimental evidence and a tentative explanation abstract the question of how useful information is in financial markets has been discussed for decades and is still unresolved in this paper we challenge the widely held belief that additional information is never a disadvantage we present results from experimental financial markets with asymmetrically informed traders in all treatments we conduct we find a j shaped distribution of returns while the best informed outperform all others average informed traders have significantly lower returns than the least informed this can mainly be attributed to trend reversals in the fundamental information prices in our markets do not reflect ree but rather naive trader equilibrium

is more information always better experimental financial markets with cumulative information abstract we study the value of information in financial markets by asking whether having more information always leads to higher returns we address this question in an experiment where information about an asset s intrinsic value is cumulatively distributed among traders we find that only the very best informed traders i e insiders significantly outperform less informed traders however there is a wide range of information levels from zero information to above average information levels where additional information does not yield higher returns the latter result implies that the value of additional information need not be strictly positive

uncertainty aversion in a heterogeneous agent model of foreign exchange rate formation this paper provides what we believe to be the first empirical test of whether investors in the foreign exchange market are uncertainty averse we do this using a heterogeneous agents model in which fundamentalist and chartist beliefs of the exchange rate co exist and are allowed to be either uncertainty neutral or uncertainty averse uncertainty aversion is modelled using the maxmin expected utility approach we find significant evidence of uncertainty aversion in the fx market where in particular fundamentalists are found to be largely uncertainty neutral while chartists are mainly uncertainty averse inclusion of uncertainty averse agents significantly improves the performance of the model

rational expectations equilibrium with conditioning on past prices a mean variance example abstract the paper uses an intertemporal mean variance model of the market for a dividend paying risky asset to analyse rational expectations equilibria when all agents condition their expectations on past rather than current prices the main result shows that if the time span between successive market periods is short the market will approximate full informational efficiency arbitrarily closely yet the returns to being informed are bounded away from zero this contrasts with the grossman stiglitz proposition that markets cannot come close to informational efficiency if the acquisition of information is costly

factor models and the correlation structure of interest rates some evidence for usd gbp dem and jpy abstract the aim of this paper is to develop models for producing accurate forecasts for the correlation of spot and forward interest rates correlation forecasts generated from factor models where the correlations are expressed as a function of few underlying factors are compared to forecasts produced by less sophisticated models like the full historical and constant correlation model contrary to previous studies where the selection of factors is rather arbitrary we test two factor identification methodologies the first is based on factor analysis and the second is based on minimising the residual cross correlations we show that a three factor model with factors identified by minimising the residual cross correlation criterion is sufficient to describe the correlation structure of interest rates furthermore we show that it might be preferable to assume that all forward rate correlations are equal rather than using a misspecified factor model and that the spot factor model developed consistently outperformed long established models like the barbell model

individual vs aggregate preferences the case of a small fish in a big pond we study the relationship between the risk preferences of individuals and the risk preferences of the aggregate economy to emphasize the vast differences that can occur between individual and market preferences brought about through aggregation we assume an economy consisting entirely of risk seekers we show that such individuals can lead to an aggregate economy that is risk averse the converse is also true an aggregate economy that exhibits risk aversion does not imply an economy of individual risk averters an economy demanding a risk premium can be formed from individuals who do not demand such compensation understanding the relationship between the preferences of individuals and the preferences of the aggregate economy is crucial for understanding the connection between the behavioral finance literature which focuses on individual preferences and the asset pricing literature which focuses on aggregate prices we discuss empirical implications of these results this paper was accepted by wei xiong finance

multi period information markets abstract this article examines the single shot decision problem of a monopolistic information seller selling a flow of information in a dynamic framework in a generalized version of wang s 1993 economy it shows that the profit maximizing strategy of the seller is to sell his information as is but only to a fraction of traders it argues that this strategy of selling information is different from that in a static model mainly due to the very different nature of constraints faced by the information seller in a dynamic framework

market equilibria with endogenous hierarchical information abstract a competitive industry in which there is both stochastic demand and a production lag is examined all agents observe costless endogenous information prices and informed agents also observe costly exogenous information solutions for market equilibria are found under quite general conditions a number of issues are examined including 1 1 the way in which prices transmit information from the informed to the uninformed 2 2 how the specification of the private information set and of the stochastic processes driving demand influence market equilibria 3 3 whether the equilibrium distribution of information may expected to be hierarchical and 4 4 whether the equilibrium distribution of information is socially optimal