TY  - JOUR
AU  - Hall,Bronwyn H.
AU  - Jaffe,Adam B.
AU  - Trajtenberg,Manuel
TI  - Market Value and Patent Citations: A First Look
JF  - National Bureau of Economic Research Working Paper Series
VL  - No. 7741
PY  - 2000
Y2  - June 2000
UR  - http://www.nber.org/papers/w7741
L1  - http://www.nber.org/papers/w7741.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

Adam B. Jaffe
MS 021
Brandeis University
Waltham, MA 02454
Tel: 781/736-3451
Fax: 781/736-3457
E-Mail: ajaffe@brandeis.edu

Manuel Trajtenberg
Eitan Berglas School of Economics
Tel-Aviv University
Tel-Aviv 69978
ISRAEL
Tel: 972-3-640-9911
Fax: 972-3-640-9908
E-Mail: manuel@post.tau.ac.il
AB  - As patent data become more available in machine-readable form, an increasing number of researchers have begun to use measures based on patents and their citations as indicators of technological output and information flow. This paper explores the economic meaning of these citation-based patent measures using the financial market valuation of the firms that own the patents. Using a new and comprehensive dataset containing over 4800 U. S. Manufacturing firms and their patenting activity for the past 30 years, we explore the contributions of R&D spending, patents, and citation-weighted patents to measures of Tobin's Q for the firms. We find that citation-weighted patent stocks are more highly correlated with market value than patent stocks themselves and that this fact is due mainly to the high valuation placed on firms that hold very highly cited patents.
ER  -