Note and comment. Keynes-plus? Effective demand and changes in firm-level R&D: an empirical note
研究发现企业所在行业的需求增长会正向影响其研发投入变化，验证了需求拉动假说，并揭示了有效需求中未被凯恩斯注意的方面。
Analysing changes over time in firm-level R and D efforts, we find that demand growth in a firm's sector of principal activity has a positive influence on changes in a firm's R and D effort, confirming Schmookler's (1969) 'demand-pull' hypothesis. This finding points to an aspect of effective demand which has never been directly noticed by Keynes or the Keynesians. Such findings are important because of evidence in the literature that a firm's innovation activities are positively related to employment growth, export intensity and profits.