1050 Massachusetts ave
Cambridge, MA 02138
NBER Working Papers and Publications
|September 2016||Technological Leadership (de)Concentration: Causes in ICTE|
with Shane Greenstein: w22631
Using patents as indicators of inventive activity, this article characterizes the concentration of origins of invention from 1976 to 2010, and how these changed over time. The analysis finds pervasive deconcentration in virtually every area related to ICT, but it can explain only a small part of this trend. Deconcentration happens despite the role of lateral entry by existing firms. New firm entry drives part of the deconcentration, but this alone cannot explain the change. A single supply factor in the market for ideas, such as the breakup of AT&T, also cannot explain the trend. Finally, eleven percent of patents change hands through mergers and acquisitions activity, but this does not make up for the declines in concentration in the origins of invention.