Score contribution per author:
α: calibrated so average coauthorship-adjusted count equals average raw count
This paper expands the Verdoorn model to include factor substitutes for labor, short-run productivity dynamics, and specific economic processes through which the growth of output may induce productivity growth. The paper compares the level and rate-of-change versions of three models. Estimated with U.S. manufacturing data, the level version of a model incorporating scale economies, economies of agglomeration, and learning-by-doing outperforms the other models. The retardation of scale effects during 1974-83 is found to explain most of the productivity slowdown during this period. Copyright 1988 by Royal Economic Society.