Out of Sight: A Study of Uncited Patents

30 Pages Posted: 7 Oct 2019 Last revised: 23 Oct 2019

See all articles by Michael Crystal

Michael Crystal

Tel Aviv University

Neil Gandal

Berglas School of Economics, Tel Aviv University; Centre for Economic Policy Research (CEPR)

Royee Shilony

Hebrew University of Jerusalem, School of Law, Students

Michal Shur-Ofry

Hebrew University of Jerusalem, Faculty of Law

Date Written: September 2019

Abstract

Scientific understanding of innovation processes and of the patent system increasingly relies on big data analyses of patent citations. Much of that research focuses on highly cited patents. This study, conversely, offers the first systematic exploration of uncited patents-patents that receive no citations. Analyzing data on all US patents issued between 1976 and 2008, we focus on the ratio of uncited patents out of all patents granted each year. We track the changes in the percentage of uncited patents during that period, and across technological fields, controlling for patents' age. We also investigate traits of uncited patents by examining the association between lack of citations and various factors including the number of inventors, number of technological subclasses, number of backward citations, and number of claims in the patent.

We find a robust pattern whereby the percentage of uncited patents declined between 1976 and the mid 1990s, but has been significantly increasing since then. These findings are consistent across technological fields and hold after controlling for patent characteristics. We discuss these and additional findings, and propose possible explanations. We suggest that the trend of increase in uncited patents raises, and reinforces, concerns regarding patent quality and "patent explosion". More broadly, our focus on "negative information" embedded in patent data opens up a new avenue for further research that can deepen our understanding of the patent system.

Keywords: Big Data, Innovation, Negative Knowledge, networks, Patent Citations, Uncited Patents

Suggested Citation

Crystal, Michael and Gandal, Neil and Shilony, Royee and Shur-Ofry, Michal, Out of Sight: A Study of Uncited Patents (September 2019). CEPR Discussion Paper No. DP13982, Available at SSRN: https://ssrn.com/abstract=3464509

Michael Crystal (Contact Author)

Tel Aviv University ( email )

Ramat Aviv
Tel-Aviv, 6997801
Israel

Neil Gandal

Berglas School of Economics, Tel Aviv University ( email )

Tel Aviv University
Tel Aviv 69978
Israel
+972 3 640 9907 (Phone)
+972 3 640 9908 (Fax)

HOME PAGE: http://www.neilgandal.com/

Centre for Economic Policy Research (CEPR)

London
United Kingdom

Royee Shilony

Hebrew University of Jerusalem, School of Law, Students ( email )

Jerusalem
Israel

Michal Shur-Ofry

Hebrew University of Jerusalem, Faculty of Law ( email )

Mount Scopus
Mount Scopus, IL 91905
Israel

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