Technological diversity of persistent innovators in Japan

We have investigated two large Japanese firms with their patent data, technological histories and product sales data of over 30 years especially in terms of intra-firm technology diversification and interactions between multiple technological trajectories. Patent data showed the process of emergencies of technological trajectories and interactions (cross-fertilization) between them quantitatively. Both persistence and diversity of technology have contributed to product diversification and sales growth. Based on our findings we have demonstrated that taking advantage of economies of scope in technology through persistence and diversification is necessary for a technology-based firm if it is to survive and to grow for a prolonged period of time. © 2003 Elsevier B.V. All rights reserved.