This book addresses the foundations of economic growth at the firm level, combining both theoretical and econometric contributions by established scholars. Challenging contributions revisit Marshall’s view on the management of innovation, investigate the decision of firms to venture into entrepreneurship and clarify some misunderstanding about Schumpeter’s ideas. The book goes on to shed light on the classical specialisation-flexibility trade-off and provides a vision on the role of the knowledge-based economy and firm networks in technology development. Firm survival and performance, price-cost margins and the determinants of research intensity are also investigated econometrically.