Social Science Practical Magic

A simple software update at the Patent Office accidentally broke the main way scientists study whether patents are actually worth anything.

SSRN · March 13, 2026 · 6286238

Nicholas Pairolero, Charles A.W. De Grazia

Why it matters

For decades, economists relied on the fact that patent applications were assigned to examiners somewhat randomly to measure how different legal decisions affected the economy. By introducing an automated system to match experts to specific inventions, the USPTO eliminated this randomness, rendering the standard tool for measuring patent value obsolete.

From the abstract

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-indifferences (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 case