This innovative book analyses the role and importance of investment in knowledge and fixed capital as two distinct sources of technological change. It provides a balance to most of the recent literature on technological change, which focuses almost exclusively on R&D and intangible investment in innovation and technological assets. The author shows how innovative investment in fixed capital still represents a central part of innovation in firms. The book begins by reviewing the major economic approaches to technology and innovation. It discusses the progressive shift from capital (embodied) investment to disembodied investment including R&D and design. Using one of the most extensive data sources, Rinaldo Evangelista empirically tests whether disembodied technological activities are more important than traditional investment in productive capital. Perhaps surprisingly, the evidence suggests that fixed productive capital emerges as the most relevant and widespread source of investment in innovation across firms and industrial sectors. The author concludes that even in high-tech industries embodied and disembodied technological activities are complementary rather than substitutive. This book will be welcomed by those interested in technological and innovation studies, industrial organization and business strategy.