18 Nov 2016Working Paper Summaries

Innovation Network

by Daron Acemoglu, Ufuk Akcigit, and William Kerr

Despite recent advances that measure how the technological development processes in innovative fields link with each other, our understanding of how progress in one technological area links to prior advances in upstream technological fields has been limited. The authors’ analysis and mapping of 1.8 million U.S. patents and their citation properties shows that a stable innovation network acts as a conduit for a cumulative process of technological and scientific progress. Upstream technological developments play an important role in the future pace and direction of patenting in downstream fields. This finding implies that if R&D slackens in one period the effects will still be felt years later in downstream fields.

Author Abstract

Technological progress builds upon itself with the expansion of invention in one domain propelling future work in linked fields. Our analysis uses 1.8 million U.S. patents and their citation properties to map the innovation network and its strength. Past innovation network structures are calculated using citation patterns across technology classes from 1975 to 1994. The interaction of this pre-existing network structure with patent growth in upstream technology fields has strong predictive power on future innovation after 1995. This pattern is consistent with the idea that when there is more past upstream innovation for a particular technology class to build on, then that technology class innovates more.