Beginning in November 2000, patent applications filed in the United States are disclosed after 18 months, rather than when the patent is granted. Using U.S. patent data from 1976-1996, we find that major inventions are most likely to be affected, as they take longer to go through the application...

The impacts of two recent changes in US patent policy depend on the length of time it takes for an invention to go through the examination process. Concerns over the distributional effects of these changes were expressed during policy debates. We use data on U.S. patent applications and grants...