NBER Working Papers by Bhaven N. Sampat

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Working Papers

January 2017Secondary Pharmaceutical Patenting: A Global Perspective
with Kenneth C. Shadlen: w23114
Pharmaceutical firms’ use of secondary patents to extend periods of exclusivity generates concerns among policymakers worldwide. In response, some developing countries have introduced measures to curb the grant of these patents. While these measures have received considerable attention, there is limited evidence on their effectiveness. We follow a large sample of international patent applications in the US, Japan, the European Patent Office, and corresponding filings in three developing countries with restrictions on secondary patents, India, Brazil, and Argentina. We examine cross-country comparisons of primary vs. secondary grant rates, consider the differential fates of “twin” applications filed in multiple countries, and undertake detailed analyses of patent prosecution in the three de...
October 2015How Do Patents Affect Follow-On Innovation? Evidence from the Human Genome
with Heidi L. Williams: w21666
We investigate whether patents on human genes have affected follow-on scientific research and product development. Using administrative data on successful and unsuccessful patent applications submitted to the US Patent and Trademark Office, we link the exact gene sequences claimed in each application with data measuring follow-on scientific research and commercial investments. Using this data, we document novel evidence of selection into patenting: patented genes appear more valuable — prior to being patented — than non-patented genes. This evidence of selection motivates two quasi-experimental approaches, both of which suggest that on average gene patents have had no effect on follow-on innovation.
January 2015Public R&D Investments and Private-sector Patenting: Evidence from NIH Funding Rules
with Pierre Azoulay, Joshua S. Graff Zivin, Danielle Li: w20889
We quantify the impact of scientific grant funding at the National Institutes of Health (NIH) on patenting by pharmaceutical and biotechnology firms. Our paper makes two contributions. First, we use newly constructed bibliometric data to develop a method for flexibly linking specific grant expenditures to private-sector innovations. Second, we take advantage of idiosyncratic rigidities in the rules governing NIH peer review to generate exogenous variation in funding across research areas. Our results show that NIH funding spurs the development of private-sector patents: a $10 million boost in NIH funding leads to a net increase of 2.3 patents. Though valuing patents is difficult, we report a range of estimates for the private value of these patents using different approaches.
January 2011The Diffusion of Scientific Knowledge Across Time and Space: Evidence from Professional Transitions for the Superstars of Medicine
with Pierre Azoulay, Joshua S. Graff Zivin: w16683
Are scientific knowledge flows embodied in individuals, or "in the air"? To answer this question, we measure the effect of labor mobility in a sample of 9,483 elite academic life scientists on the citation trajectories associated with individual articles (resp. patents) published (resp. granted) before the scientist moved to a new institution. We find that article-to-article citations from the scientific community at the superstar's origin location are barely affected by their departure. In contrast, article-to-patent citations, and especially patent-to-patent citations, decline at the origin location following a star's departure, suggesting that spillovers from academia to industry are not completely disembodied. We also find that article-to-article citations at the superstar's destinatio...

Published: The Diffusion of Scientific Knowledge across Time and Space: Evidence from Professional Transitions for the Superstars of Medicine, Pierre Azoulay, Joshua S. Graff Zivin, Bhaven N. Sampat. in The Rate and Direction of Inventive Activity Revisited, Lerner and Stern. 2012

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