Key points are not available for this paper at this time.
Wesley M. Cohen, Richard C. Levin, David C. Mowery, Firm Size and R & D Intensity: A Re-Examination, The Journal of Industrial Economics, Vol. 35, No. 4, The Empirical Renaissance in Industrial Economics (Jun., 1987), pp. 543-565
Cohen et al. (Mon,) studied this question.