[We study an equilibrium model with restricted investor participation in which strategic arbitrageurs reap profits by exploiting mispricings across different market segments. We endogenize the asset structure as the outcome of a security design game played by the arbitrageurs. The equilibrium asset structure depends realistically upon considerations such as depth and gains from trade. It is neither complete nor socially optimal in general; the degree of inefficiency depends upon the heterogeneity of investors.]

This paper studies the problem of optimal security design by a privately informed entrepreneur. In the context of a simple parametric model, it is shown that the entrepreneur does not find it profitable to float an asset that affords her an informational advantage. The reason is that, with rational, uninformed outside investors, the entrepreneur faces adverse selection in the security market, which prevents her from exploiting her position as an insider. This is true whether or not she has market power in trading the asset.

This paper introduces a theory of market incompleteness based on the information transmission role of prices and its adverse impact on the provision of insurance in financial markets. We analyse a simple security design model in which the number and payoff of securities are endogenous. Agents have rational expectations and differ in information, endowments, and attitudes toward risk. When markets are incomplete, equilibrium prices are typically partially revealing, while full relevation is attained with complete markets. The optimality of complete or incomplete markets depends on whether the adverse selection effect (the unwillingness of agents to trade risks when they are informationally disadvantaged) is stronger or weaker than the Hirshleifer effect (the impossibility of trading risks that have already been resolved), as new securities are issued and prices reveal more information. When the Hirshleifer effect dominates, an incomplete set of securities is preferred by all agents, and generates a higher volume of trade.

We study an equilibrium model with restricted investor participation in which strategic arbitrageurs reap profits by exploiting mispricings across different market segments. We endogenize the asset structure as the outcome of a security design game played by the arbitrageurs. The equilibrium asset structure depends realistically upon considerations such as depth and gains from trade. It is neither complete nor socially optimal in general; the degree of inefficiency depends upon the heterogeneity of investors. The Author 2008. Published by Oxford University Press on behalf of The Society for Financial Studies. All rights reserved. For Permissions, please email: [email protected], Oxford University Press.