This paper documents a shift in the nature of innovation in the information technology (IT) industry. Using … comprehensive data on all IT patents granted by the USPTO from 1983-2004, we find strong evidence of a change in IT innovation that … is systematic, substantial, and increasingly dependent on software. This change in the nature of IT innovation has had …

, despite sustained progress in scientific knowledge, recent productivity growth in the U.S. has been disappointing. We review … major changes in the American innovation ecosystem over the past century. The past three decades have been marked by a … growing division of labor between universities focusing on research and large corporations focusing on development. Knowledge …

knowledge is an input into internal invention, and thus, more valuable to firms with inventive capability. Using a simple model … of innovation and imitation, we explore how inventive capability affects a firm's R&D investments, and thus whether and … external knowledge as well as the supply of external inventions. In an advance over the literature, we treat firm inventive …

knowledge is an input into internal invention, and thus, more valuable to firms with inventive capability. Using a simple model … of innovation and imitation, we explore how inventive capability affects a firm's R&D investments, and thus whether and … external knowledge as well as the supply of external inventions. In an advance over the literature, we treat firm inventive …