The starting point for the research contained in The Changing Roles of Debt and Equity in Financing U.S. Capital Formation was a pair of broad questions about the markets in which the debt and equity securities of business corporations undertaking physical capital formation are issued, traded, and priced. First, how have the markets priced corporate debt and equity securities in the past, and what aspects of the markets' functioning have accounted for these evaluations? Second, how have corporations' financing patterns responded in this environment, and what specific aspects of the interaction between the market mechanism and corporate financing decisions have accounted for these responses? This volume, consists of six papers addressing these questions presented at a conference held at Williamsburg, Va., 2-3 April 1981.