To help understand how firms develop and maintain dynamic capabilities, we examine the effects of the dynamics, management, and governance of R & D and marketing resource deployments on firm-level economic performance. In a sample of technology-based entrepreneurial firms, we find that a history of increased investments in marketing is an enduring source of competitive advantage. We also find that managers' firm-specific experience positively moderates the relationship between R & D deployment intensity and economic returns. In addition, institutional ownership boosts economic returns from marketing deployments by subjecting these deployments to increased scrutiny and by sending positive signals to the market about the firm. Copyright © 2005 John Wiley & Sons, Ltd.