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Acknowledgments

We appreciate and acknowledge the support of the Harvard Business School Department
of Research, the National Renewable Energy Laboratory, and NSF 0830287 (Creating a
Patent Collaboration Network Database to Examine the Social Production of
Knowledge). The authors would like to thank R. Lai and A. D’Amour of Harvard
Business School and C. Worley of Colorado School of Mines for their assistance with
data and analysis and V. Cardona of Heslin Rothenberg Farley & Mesiti P.C., Albany,
New York, for sharing their patent search methodology. D. Bilello, T. James, D. Kline,
and R. Newmark of NREL and L. Bony of the Rocky Mountain Institute provided helpful
comments on the paper. All errors remain ours.

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