Economic and management perspectives on management strategy can and should be integrated. The intermediation theory of the firm and models of market microstructure provide a basis for advancing the integration of management and economics perspectives. In particular, the theory allows for a combination of economic approaches such as Porter's work on competitive strategy with management approaches such as work on the abilities and resources of the organization. The article presents a unified strategy framework based on transaction costs and the intermediation theory of the firm. Copyright © 2003 John Wiley & Sons, Ltd.