Defining social capital in terms of the information benefits available to a firm due to its strategic alliances tie present a theory, of social capital that conceptualizes it as a multidimensional construct. We draw from the literature to argue that social capital yields three distinctly different kinds of information benefits in the form of information volume, information diversity, and information richness. This extends current theoretical and empirical research by specifying and empirically demonstrating three interrelated vet distinct dimensions of social capital. Firms vary in their levels of social capital not just on their structural position in an alliance network but also in the dynamics that underlie alliance formation and maintenance. More importantly, the different dimensions of social capital theoretically provide differential benefits. We establish the construct validity of our proposed three-dimensional conceptualization of social capital using longitudinal data on tire population of strategic alliances formed during the period 1980-94 by firms in the global steel industry. In addition, rose establish predictive vadility by demonstrating drat the information dimensions have differential effects oil firm performance, using fire: nationality as a contingency. Copyright (C) 2002 John Wiley Sons, Ltd.