TY  - JOUR
AU  - Hall,Bronwyn H.
AU  - Griliches,Zvi
AU  - Hausman,Jerry A.
TI  - Patents and R&D:  Searching for a Lag Structure
JF  - National Bureau of Economic Research Working Paper Series
VL  - No. 1227
PY  - 1983
Y2  - November 1983
UR  - http://www.nber.org/papers/w1227
L1  - http://www.nber.org/papers/w1227.pdf
N1  - Author contact info:
Bronwyn H. Hall
Dept. of Economics
549 Evans Hall
UC Berkeley
Berkeley, CA 94720-3880
Tel: 510/642-3878
Fax: 510/548-5561
E-Mail: bhhall@nber.org

Zvi Griliches
E-Mail: N/A user is deceased

Jerry A. Hausman
Department of Economics
MIT, Room E52-271A
50 Memorial Drive
Cambridge, MA  02139
Tel: 617/253-3644
Fax: 617/253-1330
E-Mail: jhausman@mit.edu
AB  - This paper extends earlier work on the R&D to patents relationship (Pakes-Griliches 1980, and Hausman, Hall, and Griliches, 1984) to a larger but shorter panel of firms. Using both non-linear least squares and Poisson type models to treat the problem of discreteness in the dependent variable the paper tries to discern the lag structure of this relationship in greater detail. Since the available time series are short, two different approaches are pursued in trying to solve the lag truncation problem: In the first the influence of the unseen past is assumed to decline geometrically; in the second,the unobserved past series are assumed to have followed a low order autoregression. Neither approach yields strong evidence of a long lag. The available sample, though numerically large,turns out not to be particularly informative on this question. It does reconfirm, however, a significant effect of R&D on patenting (with most of it occurring in the first year or two) and the presence of rather wide and semi-permanent differences among firms in their patenting policies.
ER  -