Claim Amendments as the Result of Strategic Patenting and as a Driver for Patent Value

Florian Köhler
TU Berlin

Knut Blind
Chair for Innovation Economics - TU Berlin

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     Last modified: February 26, 2010

Abstract
We study the effect of strategic patenting motives on the characteristics of a company's patent portfolios. First, we analyze the frequency of change requests (``amendments") to the originally filed claims. We theorize that firms that patent for technology exchange have an incentive to shift the exact scope of a patent application to fit potential demand in the market for technology. Subsequently, we address the relationship of amendments and forward citations. As amendments allow the applicant to incorporate knowledge gained after the original filing into the claims, amendments can result in patents of higher quality.
We rely on survey data from 441 German companies and matched data on their respective patent portfolio including new EPO information on the application process. Using multivariate tobit models as well as two-staged least squares models, we find that, first, the technology exchange motive is related to a higher number of amendments, implying a strategic use of this instrument. Secondly, amendments are also associated with higher levels of citations, which suggests that they might be an instrument to raise patent quality or value. Since amendments are also partly responsible for the uncertainty in the patent system, the resulting trade-off needs to be taken into account.