Close to You? Bias and Precision in Patent-Based Measures of Technological Proximity
Patent data have been widely used in research on technological innovation to characterize firms' locations as well as the proximities among firms in knowledge space. Researchers could measure proximity among firms with a variety of measures based on patent class data, including Euclidean distance, correlation, and angle between firms' patent class distributions. Alternatively, one could measure proximity using overlap in cited patents. We point out that measures of proximity based on small numbers of patents are imprecisely measured random variables. Measures computed on samples with few patents generate both biased and imprecise measures of proximity. We explore the effects of larger sample sizes and coarser patent class breakdowns in mitigating these problems. Where possible, we suggest that researchers increase their sample sizes by aggregating years or using all of the listed patent classes on a patent, rather than just the first.
|Date of creation:||Aug 2007|
|Date of revision:|
|Publication status:||published as Benner, Mary & Waldfogel, Joel, 2008. "Close to you? Bias and precision in patent-based measures of technological proximity," Research Policy, Elsevier, vol. 37(9), pages 1556-1567, October.|
|Contact details of provider:|| Postal: |
Web page: http://www.nber.orgEmail:
More information through EDIRC
Please report citation or reference errors to , or , if you are the registered author of the cited work, log in to your RePEc Author Service profile, click on "citations" and make appropriate adjustments.:
- Hall, B. & Jaffe, A. & Trajtenberg, M., 2001.
"The NBER Patent Citations Data File: Lessons, Insights and Methodological Tools,"
2001-29, Tel Aviv.
- Bronwyn H. Hall & Adam B. Jaffe & Manuel Trajtenberg, 2001. "The NBER Patent Citation Data File: Lessons, Insights and Methodological Tools," NBER Working Papers 8498, National Bureau of Economic Research, Inc.
- Hall, Bronwyn H & Jaffe, Adam B & Trajtenberg, Manuel, 2001. "The NBER Patent Citations Data File: Lessons, Insights and Methodological Tools," CEPR Discussion Papers 3094, C.E.P.R. Discussion Papers.
- Brian S. Silverman, 1999. "Technological Resources and the Direction of Corporate Diversification: Toward an Integration of the Resource-Based View and Transaction Cost Economics," Management Science, INFORMS, vol. 45(8), pages 1109-1124, August.
- Juan Alcácer & Michelle Gittelman, 2006. "Patent Citations as a Measure of Knowledge Flows: The Influence of Examiner Citations," The Review of Economics and Statistics, MIT Press, vol. 88(4), pages 774-779, November.
- Manuel Trajtenberg & Adam B. Jaffe & Michael S. Fogarty, 2000. "Knowledge Spillovers and Patent Citations: Evidence from a Survey of Inventors," American Economic Review, American Economic Association, vol. 90(2), pages 215-218, May.
- Lori Rosenkopf & Paul Almeida, 2003. "Overcoming Local Search Through Alliances and Mobility," Management Science, INFORMS, vol. 49(6), pages 751-766, June.
- Constance E. Helfat, 1994. "Evolutionary Trajectories in Petroleum Firm R&D," Management Science, INFORMS, vol. 40(12), pages 1720-1747, December.
- Lucia Piscitello, 2004. "Corporate diversification, coherence and economic performance," Industrial and Corporate Change, Oxford University Press, vol. 13(5), pages 757-787, October.
- Fleming, Lee & Sorenson, Olav, 2001. "Technology as a complex adaptive system: evidence from patent data," Research Policy, Elsevier, vol. 30(7), pages 1019-1039, August.
- Adam B. Jaffe & Manuel Trajtenberg & Rebecca Henderson, 1992.
"Geographic Localization of Knowledge Spillovers as Evidenced by Patent Citations,"
NBER Working Papers
3993, National Bureau of Economic Research, Inc.
- Jaffe, Adam B & Trajtenberg, Manuel & Henderson, Rebecca, 1993. "Geographic Localization of Knowledge Spillovers as Evidenced by Patent Citations," The Quarterly Journal of Economics, MIT Press, vol. 108(3), pages 577-98, August.
- Jaffe, A.B. & Trajtenberg, M., 1992. "Geographic Localization of Knowledge Spillovers as Evidenced by Patent Citations," Papers 14-92, Tel Aviv.
- Jaeyong Song & Paul Almeida & Geraldine Wu, 2003. "Learning--by--Hiring: When Is Mobility More Likely to Facilitate Interfirm Knowledge Transfer?," Management Science, INFORMS, vol. 49(4), pages 351-365, April.
When requesting a correction, please mention this item's handle: RePEc:nbr:nberwo:13322. See general information about how to correct material in RePEc.
For technical questions regarding this item, or to correct its authors, title, abstract, bibliographic or download information, contact: ()
If references are entirely missing, you can add them using this form.