Working Paper | HBS Working Paper Series | 2014

Codifying Prior Art and Patenting: Natural Experiment of Herbal Patent Prior Art Adoption at the EPO and USPTO

by Prithwiraj Choudhury and Tarun Khanna


In the patenting literature, economists and legal scholars have focused on the question of improving the quality of prior art available to patent examiners and mitigating the filing and granting of patents where prior art exists in common knowledge. In this paper, we create a unique dataset of Chinese and Indian herbal patents filed on the USPTO and EPO between 1977 and 2010 and exploit a natural experiment where the USPTO and EPO adopted a codified database of traditional herbal prior art at different points in time. This initiative was titled the 'Traditional Knowledge Depository Library' (TKDL) and was pioneered by Indian state-owned R&D labs and provided the EPO and USPTO with systematic evidence of prior art on herbal patents based on a translation of ancient Indian texts. We conduct additional analyses to establish that the time lag of the USPTO adopting the TKDL agreement compared to the EPO was related to idiosyncratic differences in how the agreements were structure and negotiated, not differences in policy towards herbal patents at the EPO and USPTO. We also find that the adoption of TKDL appears to shift patenting in the West from pure herbal remedies that can be contested in court, to new applications involving herbals and synthetics, which are less contestable. Further, we study the ethnic origins of the inventors of herbal patents filed on the USPTO. For this analysis, we use ethnic name matching for all patentees of herbal patents. We also exploit an exogenous reduction in H1B (visa) quotas and find that herbal patents filed by Western firms based in the U.S. are driven by scientists of ethnic Indian and Chinese origin.

Keywords: Patents; Plant-Based Agribusiness; Ethnicity; Health Care and Treatment; Pharmaceutical Industry; Agriculture and Agribusiness Industry; China; India;


Choudhury, Prithwiraj, and Tarun Khanna. "Codifying Prior Art and Patenting: Natural Experiment of Herbal Patent Prior Art Adoption at the EPO and USPTO." Harvard Business School Working Paper, No. 14-079, February 2014.