Daniel K.N. Johnson

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NBER Working Papers and Publications

March 2003Time in Purgatory: Determinants of the Grant Lag for U.S. Patent Applications
with David Popp, Ted Juhl: w9518
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 to determine the factors influencing the length of the patent examination process. We augment this analysis with interviews of patent examiners, leading to a better understanding of the examination process. Our analysis finds that differences across technology are most important. Inventor characteristics have statistically significant effects, but the magnitudes are small.

Published: Popp, David, Ted Juhl and Daniel K.N. Johnson. “Time In Purgatory: Determinants of the Grant Lag for U.S. Patent Applications." The B.E. Journal of Economic Analysis & Policy, Vol. 4 (2004) Issue 1

July 2001Forced Out of the Closet: The Impact of the American Inventors Protection Act on the Timing of Patent Disclosure
with David Popp: w8374
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 process. We provide evidence that this change will result in faster knowledge diffusion, and conclude with a simulation of the law's potential effect on patent grants.

Published: Johnson, Daniel K. N. and David Popp. "Forced Out Of The Closet: The Impact Of The American Inventors Protection Act On The Timing Of Patent Disclosure," Rand Journal of Economics, 2003, v34(1,Spring), 96-112. citation courtesy of

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