Capital Structure Equilibrium under Market Imperfections and Incompleteness

Abstract

This paper generalizes Miller's supply‐side equilibrium argument to other forms of capital market imperfections and incompleteness. If corporations possess a comparative advantage in dealing with these imperfections, they have an incentive to act as financial intermediaries. Corporations' attempts to profit from these intermediation activities dictate an optimal capital structure for the corporate sector as a whole, but in equilibrium the capital structure of any single firm is a matter of indifference. In addition, the positive role that corporate finance plays in completing the market restores standard perfect market results on asset pricing and the associated portfolio separation properties.