Patent Citations Reexamined: New Data and Methods
58 Pages Posted: 14 Jan 2016 Last revised: 10 Aug 2017
Date Written: August 9, 2017
Many studies of innovation rely on patent citations to measure intellectual lineage and impact. In this article, we use a vector space model of patent similarity and new data from the USPTO to show that the nature of patent citations has changed dramatically in recent years. Today, far more citations are created per patent, and the mean technological similarity between citing and cited patents has fallen. We link these developments to changes in the data generating process for patent citations. We also demonstrate that data limitations have generated overstated results in several important articles using patent citations.
Keywords: patents, citations, innovation economics, USPTO, examiner, applicant, rejections
JEL Classification: O3, O34
Suggested Citation: Suggested Citation