Article | Review of Economics and Statistics | November 2006

Patent Citations as a Measure of Knowledge Flows: The Influence of Examiner Citations

by Juan Alcacer and Michelle Gittelman

Abstract

Analysis of patent citations is a core methodology in the study of knowledge diffusion. However, citations made by patent examiners have not been separately reported, adding unknown noise to the data. We leverage a recent change in the reporting of patent data showing citations added by examiners. The magnitude is high: two-thirds of citations on the average patent are inserted by examiners. Furthermore, 40% of all patents have all citations added by examiners. We analyze the distribution of examiner and inventor citations with respect to self-citation, distance, technology overlap, and vintage. Results indicate that inferences about inventor knowledge using pooled citations may suffer from bias or overinflated significance levels.

Keywords: Patents; Knowledge Sharing; Management Analysis, Tools, and Techniques; Technology; Prejudice and Bias; Change;

Citation:

Alcacer, Juan, and Michelle Gittelman. "Patent Citations as a Measure of Knowledge Flows: The Influence of Examiner Citations." Review of Economics and Statistics 88, no. 4 (November 2006): 774–779.