Fundamental Stocks of Knowledge and Productivity Growth
构建了学术科学积累的新指标，检验其对制造业生产率数据的解释力，发现知识是生产率增长的主要贡献者，且学术研究对生产率的影响存在约20年的滞后。
This paper develops new indicators of accumulated academic science and tests their explanatory power on productivity data from manufacturing industries. Knowledge is found to be a major contributor to productivity growth. Furthermore, a lag in effect of roughly 20 years is found between the appearance of research in the academic cmmunity and its effect on productivity in the form of knowledge absorbed by an industry. Academic technology and academic science filtered through interindustry spillovers exhibit lags of roughly 10 and 30 years each. Thus implied search and gestation times far exceed developmental periods in the studies of R&D. A clear implication is that basic research declines relative to development in the face of an exogenous rise in the real rate of interest. Copyright 1990 by University of Chicago Press.