Research productivity and patent quality: measurement with multiple indicators

Jean Lanjouw and Mark Schankerman

LSE Research Online Documents on Economics from London School of Economics and Political Science, LSE Library

Abstract: We analyse the determinants of the decline in measured research productivity (the patent/R&D ratio) using panel data on manufacturing firms in the U.S. for the period 1980-93. We focus on three factors: the level of demand, the quality of patents, and technological exhaustion. We first develop an index of patent ‘quality’ using detailed information on patents in the U.S. in seven technology fields. Using a factor model, we construct a minimum-variance index based on four patent characteristics and show that using multiple indicators substantially reduces the measured variance in quality. We then show that research productivity at the firm level is negatively related to the patent quality index and the level of demand, as predicted by an optimizing model of R&D, and positively related to the stock market valuation of patented innovations held by firms.

Keywords: Patents; R&D Productivity; Technological Exhaustion. (search for similar items in EconPapers)
JEL-codes: O31 O32 (search for similar items in EconPapers)
Pages: 45 pages
Date: 2002-12
References: View references in EconPapers View complete reference list from CitEc
Citations: View citations in EconPapers (1)

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http://eprints.lse.ac.uk/3729/ Open access version. (application/pdf)

Related works:
Working Paper: Research Productivity and Patent Quality: Measurement with Multiple Indicators (2002)
Working Paper: Research Productivity and Patent Quality: Measurement with Multiple Indicators (2002)
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Persistent link: https://EconPapers.repec.org/RePEc:ehl:lserod:3729

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