Rahi, Rohit and Gottardi, Piero (2001) Efficiency properties of rational expectations equilibria with asymmetric information. Discussion paper, 381. Financial Markets Group, London School of Economics and Political Science, London, UK.
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In this paper we provide a characterization of the welfare properties of rational expectations equilibria of economies in which, prior to trading, agents have some information over the realization of uncertainity. We study a model with asymmetrically informed agents, treating symmetric information as a limiting case. Trade takes place in asset markets that may or may not be complete. We show that equilibria are characterized by two forms of inefficiency, price inefficiency and spanning inefficiency, and that generically both of them are present. Price inefficiency arises whenever equilibrium prices reveal some information. It formalizes and generalizes the so-called Hirshleifer effect, by showing that generically an interim Pareto improvement is possible even conditional on the information that is available to agents in equilibrium; the primary source of the inefficiency is a pecuniary externality. Spanning ineffiency, on the other hand, arises if prices are not fully revealing and markets are incomplete relative to the uncertainity faced by agents in equilibrium. In this case, an ex-post improvement can generically be implemented by providing agents with more information, thus expanding their risk-sharing opportunities and reducing informational asymmetries, even though this additional information restricts the set of allocations that are incentive compatible and individually rational.
|Item Type:||Monograph (Discussion Paper)|
|Additional Information:||© 2001 The Authors|
|Uncontrolled Keywords:||Rational expectations equilibrium, Asymmetric information, Incomplete markets|
|Library of Congress subject classification:||H Social Sciences > HG Finance
H Social Sciences > HB Economic Theory
|Journal of Economic Literature Classification System:||D - Microeconomics > D5 - General Equilibrium and Disequilibrium > D52 - Incomplete Markets
D - Microeconomics > D8 - Information, Knowledge, and Uncertainty > D82 - Asymmetric and Private Information
D - Microeconomics > D6 - Welfare Economics > D60 - General
|Sets:||Research centres and groups > Financial Markets Group (FMG)
Collections > Economists Online
Departments > Economics
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