Automated routing, patent examiner specialization, and quasi-random assignment at the USPTO

In October 2020, the United States Patent and Trademark Office (USPTO) introduced an automated process for routing new patent applications, in part to increase examiner specialization. In this research note, we first assess whether the USPTO achieved this objective using a difference-in-differences (DiD) research design on a sample of applications assigned to examiners between 2018 and 2021. The new routing system increased technical overlap between examiner work histories and newly assigned cases by 57 percent, indicating a substantial increase in examiner specialization across the agency. In addition, we show that automated routing — largely unknown in the academic literature — effectively eliminated quasi-random assignment of applications to examiners. Given the importance of quasi-random assignment for empirical research, we discuss our findings within this context and potential impact on future research. • In 2020, the USPTO introduced an automated routing system for applications to examiners. • The 2020 policy change increased examiner specialization by over 50%. • Specialization gains occurred broadly across Technology Centers and Art Units. • Automated routing effectively ended quasi-random assignment of patent applications to examiners.