Score contribution per author:
α: calibrated so average coauthorship-adjusted count equals average raw count
The author applies the method of R. J. Caballero and R. K. Lyons to industry-level data for U.K. manufacturing. He finds evidence for a positive external effect, arising from the expansion of manufacturing as a whole, but expansion at the sectoral level was found not to generate external effects. Nor was any evidence found for increasing returns that are internal to the industry: here returns appear to be constant. The author argues that external effects at the level of aggregate manufacturing cannot be explained away as due to measurement error or cyclical effects. However, alternative explanations, such as economywide shocks, cannot be totally excluded. Copyright 1996 by Blackwell Publishing Ltd.