Working Paper: NBER ID: w23114
Authors: Bhaven N. Sampat; Kenneth C. Shadlen
Abstract: 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 developing countries. Our analyses indicate that measures to restrict secondary patents in developing countries are having limited impact. In none of these three countries are specific policies toward secondary patents the principal determinant of grant rates. Our analyses also suggest the importance of other procedural aspects of patent systems, beyond the formal policies targeting secondary applications, that affect outcomes for these applications in developing countries.
Keywords: pharmaceutical patents; secondary patents; public health; developing countries; patent policy
JEL Codes: I18; O34
Edges that are evidenced by causal inference methods are in orange, and the rest are in light blue.
| Cause | Effect |
|---|---|
| Measures to restrict secondary patents in India, Brazil, and Argentina (O34) | Grant rates for secondary patents (O38) |
| Argentina's restrictions on secondary patents (L65) | Grant rates for secondary patents in Argentina (L49) |
| Patent office backlogs in developing countries (O34) | Rate of application abandonment (J63) |