Measuring the Technological Uniqueness of US and EP Patents

46 Pages Posted: 15 May 2018 Last revised: 12 Oct 2018

See all articles by Jonathan H. Ashtor

Jonathan H. Ashtor

Paul, Weiss, Rifkind, Wharton & Garrison LLP; Benjamin N. Cardozo School of Law

Date Written: October 1, 2018


I construct a measure of the technological uniqueness of a patented invention (“Uniqueness” or “UNQ”), based on linguistic analysis of claim text. Specifically, I employ advanced computational linguistic techniques to analyze the claims of all U.S. patents issued from 1976-2017, nearly 6 million patents in total, and I calculate the average degree of conceptual similarity of each patented invention to all others in the same technology field and time period cohort. Uniqueness is observed in the inverse, such that a patent with a lower measure of cohort similarity has greater Uniqueness, and vice versa. I validate the resulting measure using multiple established proxies for technological uniqueness, together with a set of pioneering patents and actual USPTO Office Action rejections. Finally, I extend the methodology to all issued EP patents, over 1.6 million in total, and validate the results against the OECD’s patent metrics.

Using the measure, I study the relationship of Uniqueness to patent value and cumulative technological development. I find significant correlations between Uniqueness and patent value, as measured by returns to firm innovation and stock market responses to patent issuance. I also find strong correlations with cumulative innovation, as measured by forward citations. Furthermore, I find that patents of greater Uniqueness give rise to more important citations, as they are more frequently cited in Office Action rejections of future patents. I also investigate how Uniqueness relates to the USPTO examination process. In particular, I find that UNQ can be measured based on either an issued patent or an early-stage patent application.

Next, I analyze the characteristics of highly Unique patents. First, I find that patents generated from basic scientific research tend to have greater Uniqueness, as measured by public grant funding and citations to non-patent scientific literature. I further find that the Uniqueness of U.S. and E.P. patents correlates significantly with each of the OECD’s patent metrics.

Finally, I observe trends in Uniqueness over a forty-year timespan. This reveals a noticeable, albeit slight, trend in certain technology fields in recent years, which corresponds to the lifecycle of technological maturation in those sectors.

Keywords: patent, novelty, linguistic, computational, measure, innovation

JEL Classification: K49, D23, O31, O33, O34

Suggested Citation

Ashtor, Jonathan H., Measuring the Technological Uniqueness of US and EP Patents (October 1, 2018). Available at SSRN: or

Jonathan H. Ashtor (Contact Author)

Paul, Weiss, Rifkind, Wharton & Garrison LLP ( email )

New York, NY 10019
United States
212-373-3823 (Phone)

Benjamin N. Cardozo School of Law ( email )

United States

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