Technological entry, exit and survival: an empirical analysis of patent data

This paper provides new empirical evidence on the patterns of technological entry and exit across sectors and over time. We define 'new' innovators-fi rms which innovate for the first time, and 'ex'-innovators-previous innovat ors that do not innovate any more. We distinguish also between 'real' and ' lateral' entry and exit. The analysis is based on patent data (European Pat ent Office) for 49 technological classes in six countries (USA, Japan, Germ any, UK, France and Italy) over the period 1978-1991. We find that innovati ve turbulence is relevant and that it is a composite phenomenon, in which r eal innovative entrants/exiters and lateral entrants/exiters play different roles. We then examine the patterns of survival of innovative entrants and find that most of the entrants are occasional innovators, while persistent innovators are few in number but large in terms of patents. Subsequently, we analyze differences in the patterns of technological entry and exit at t he sectoral level. Finally, the role of national systems of innovation in a ffecting innovative entry and exit is examined. (C) 1999 Elsevier Science B .V. All rights reserved.