TY  - JOUR
AU  - Kerr, William R
TI  - Breakthrough Inventions and Migrating Clusters of Innovation
JF  - National Bureau of Economic Research Working Paper Series
VL  - No. 15443
PY  - 2009
Y2  - October 2009
DO  - 10.3386/w15443
UR  - http://www.nber.org/papers/w15443
L1  - http://www.nber.org/papers/w15443.pdf
N1  - Author contact info:
William R. Kerr
Harvard Business School
Rock Center 212
Soldiers Field
Boston, MA 02163
Tel: 617/496-7021
E-Mail: wkerr@hbs.edu
M1  - published as William R. Kerr. "Breakthrough Inventions and Migrating Clusters of Innovation," in Edward L. Glaeser, Stuart S. Rosenthal and William C. Strange, organizers, "Cities and Entrepreneurship" Journal of Urban Economics, Vol. 67, no. 1 (2010)

AB  - We investigate the speed at which clusters of invention for a technology migrate spatially following breakthrough inventions.  We identify breakthrough inventions as the top one percent of US inventions for a technology during 1975-1984 in terms of subsequent citations.  Patenting growth is significantly higher in cities and technologies where breakthrough inventions occur after 1984 relative to peer locations that do not experience breakthrough inventions.  This growth differential in turn depends on the mobility of the technology's labor force, which we model through the extent that technologies depend upon immigrant scientists and engineers.  Spatial adjustments are faster for technologies that depend heavily on immigrant inventors.  The results qualitatively confirm the mechanism of industry migration proposed in models like Duranton (2007).
ER  -