Close to you?
Subtitle: bias and precision in patent-based measures of technological proximity
By: Mary Benner, Joel Waldfogel
Contributors: Waldfogel, Joel, 1962-; National Bureau of Economic Research
Series: NBER working paper series -- working paper 13322; Working paper series (National Bureau of Economic Research : Online) -- working paper no. 13322.
Publisher: National Bureau of Economic Research
Published: 2007
Place of publication: Cambridge, MA
Language: eng
Format: [electronic resource]
Description: "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"--National Bureau of Economic Research web site.
Notes: Title from PDF file as viewed on 8/29/2007.

Includes bibliographical references.

Also available in print.

System requirements: Adobe Acrobat Reader.

Mode of access: World Wide Web.