Corporate technological competence and the evolution of technological diversification Drawing upon evolutionary economics and resource based approaches the author utilises US patent data from 1930 1990 to examine the persistence of corporate technological competencies and their gradual erosion through diversifying incremental change. The book explores the changing nature of this diversification with respect to firm size technological relatedness and technological complexity in 32 firms distributed across four broadly defined industrial sectors. The findings suggest that industry and corporate technological profiles remain strong but are becoming blurred by the pervasiveness of general purpose technologies. Although historically diversification is associated with an increase in firm size the author argues that in recent times it results from technological relatedness and complexity. This book will appeal to industrial and business economists historians of business and technology and students and scholars of technology management