Patent Citations as a Measure of Knowledge Flows: The Influence of Examiner Citations
利用专利数据报告方式的变化，分离出审查员添加的引用，发现平均每件专利三分之二的引用由审查员插入，40%的专利所有引用均为审查员添加，并分析了审查员与发明人引用在自引、距离、技术重叠和年代上的分布差异，指出使用混合引用推断发明人知识可能存在偏差或显著性水平虚高。
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. Copyright by the President and Fellows of Harvard College and the Massachusetts Institute of Technology.