Beyond the front page: In‑text citations to patents as traces of inventor knowledge
Cyril Verluise, Gabriele Cristelli, Kyle Higham, Gaétan de Rassenfosse
Strategic Management Journal forthcoming
Research Question
How do in‑text patent citations differ in their ability to trace inventor knowledge flows compared to front‑page citations?
Why Do We Care
Understanding knowledge flows among inventors and firms is crucial for fostering innovation. Traditional measures based on front‑page citations are limited, as they often reflect legal requirements and do not necessarily capture the true origins of knowledge. By identifying in‑text patent citations, we shed light on genuine technological linkages, offering more reliable data for assessing how knowledge diffuse within and between organizations.
What Did We Do
We analyzed a dataset of 49.5 million in‑text patent citations matched to approximately 8 million unique U.S. patent documents, focusing on patents filed mainly after 1976. We used geographic and semantic analysis methods to compare in‑text citations with front‑page citations and also replicated a previous study on knowledge diffusion using citation data. We conducted a survey of patent attorneys to validate assumptions regarding the origins of these citations.
What Did We Find
We find that in‑text citations are 19% to 44% more likely to originate from inventors than front‑page citations, indicating stronger connections to genuine knowledge flows. Additionally, in‑text citations are more geographically localized and semantically closer to the citing patents, underscoring their value as indicators of innovation dynamics. Our replication of Balsmeier et al. (2023) also demonstrates that, while in‑text citations are less frequent, they provide robust estimates for analyzing knowledge diffusion patterns.
Primary Data
- 49.5 million in‑text citations matched to about 8 million unique U.S. patent documents, predominantly from patent applications filed after 1976.
Assumptions
- In‑text citations provide a more accurate representation of inventors' contributions compared to front‑page citations.
- The survey responses from patent attorneys accurately reflect the origins of the citations.
- Geographic and semantic proximity between citing and cited patents are valid indicators of knowledge flow.