extend earlier studies of the societal
effect of ICTs.
Our analysis is not directly able to
explain conclusively why ICT inventions are substantially more influential
than others but points to three possible
factors we hope open avenues for further research: ICTs may be more cumulative than other technology fields,
whereby subsequent inventions build
more closely on previous inventions;
as a field with a strong scientific knowledgebase, ICT inventions may depend
on scientific breakthroughs that enable
cumulative invention of industrial applications and lead to highly cumulative patterns of patent citations. ICTs
may be more “generative” than other
technologies; such generativity stems
from the openness of ICT systems, by
design, to enable complementary applications, and from the inherent flexibility of ICTs that creates technological
opportunity for invention. And finally,
ICTs may have exceptional influence
on invention in a range of technological
fields because they enable the capture,
manipulation, and communication of
information itself, and information is
the fundamental ingredient of invention. In a related study, we call ICTs “
invention machines” and further explore
the nature of ICTs as general-purpose
invention technologies. 15
1. Agrawal, A. and Goldfarb, A. Restructuring research:
Communication costs and the democratization of
university innovation. American Economic Review 98, 4
(Sept. 2008), 1578–1590.
2. Becchetti, L., Bedoya, D.A. L., and Paganetto, L. ICT
investment, productivity and efficiency: Evidence
at firm level using a stochastic frontier approach
(in English). Journal of Productivity Analysis 20, 2
(Sept. 2003), 143–167.
3. Bertschek, I., Cerquera, D., and Klein, G. J. More bits,
more bucks? Measuring the impact of broadband
Internet on firm performance. Information Economics
and Policy 25, 3 (Sept. 2013), 190–203.
4. Bloom, N., Sadun, R., and Ven Reenen, J. Americans
do IT better: U.S. multinationals and the productivity
miracle. American Economic Review 102, 1 (Feb.
5. Bresnahan, T.F. and Greenstein, S. The economic
contribution of information technology: Towards
comparative and user studies. Journal of Evolutionary
Economics 11, 1 (Jan. 2001), 95–118.
6. Bresnahan, T. F. and Trajtenberg, M. General-purpose
technologies: Engines of growth? Journal of
Econometrics 65, 1 (Jan. 1995), 83–108.
7. Brynjolfsson, E. and Hitt, L.M. Computing productivity:
Firm-level evidence. Review of Economics and
Statistics 85, 4 (Nov. 2003), 793–808.
8. Czernich, N., Falck, O., Kretschmer, T., and
Woessmann, L. Broadband infrastructure and growth.
The Economic Journal 121, 552 (May 2011), 505–532.
9. Dechezleprêtre, A., Martin, R., and Mohnen,
M. Knowledge spillovers from clean and dirty
technologies: A patent-citation analysis. Centre for
Climate Change Economics and Policy Working Paper
No. 151 and Grantham Research Institute on Climate
Change and the Environment Working Paper No. 135.
London School of Economics and Political Science,
London, U.K., 2013.
10. Forman, C. and van Zeebroeck, N. From wires to
partners: How the Internet has fostered R&D
collaborations within firms. Management Science 58,
8 (Aug. 2012), 1549–1568.
11. Hall, B.H., Jaffe, A.B., and Trajtenberg, M. Market value
and patent citations. RAND Journal of Economics 36, 1
(Spring 2005), 16–38.
12. Jaffe, A.B. and Trajtenberg, M. International
knowledge flows: Evidence from patent citations.
Economics of Innovation and New Technology 8, 1-2
13. Kim, P.R. and Hwang, S. H. A study on the identification
of cutting-edge ICT-based converging technologies.
E TRI Journal 34, 4 (Aug. 2012), 602–612.
14. Koutroumpis, P. The economic impact of
broadband on growth: A simultaneous approach.
Telecommunications Policy 33, 9 (Oct. 2009), 471–485.
15. Koutroumpis, P., Leiponen, A., and Thomas, L. D. W.
Invention machines: How control instruments and
information technologies drove global technological
progress over a century of invention. Working Paper.
Imperial College London, U.K., 2017.
16. Page, L., Brin, S., Motwani, R., and Winograd, T. The
PageRank Citation Ranking: Bringing Order to the Web.
Technical Report. Stanford InfoLab, Mountain View,
CA, 1999; http://ilpubs.stanford.edu/422/1/1999-66.pdf
17. Solow, R. We’d better watch out. The New York Times
Book Review (July 12, 1987).
18. Trajtenberg, M. A penny for your quotes: Patent
citations and the value of innovations. RAND Journal
of Economics 21, 1 (Spring 1990), 172–187.
19. Van Reenen, J., Bloom, N., Draca, M., Kretschmer, T.,
and Sadun, R. The Economic Impact of IC T. In Final
Report. Center for Economic Performance, London
School of Economics, London, U.K., 2010.
Pantelis Koutroumpis ( firstname.lastname@example.org)
is a research fellow at Imperial College Business School,
London, U.K., and a fellow of the Columbia Institute of
Tele-Information at Columbia University, New York.
Aija Leiponen ( email@example.com) is an associate
professor in the Dyson School of Applied Economics and
Management, Cornell University, Ithaca, NY, and a visiting
research fellow in the Research Institute of the Finnish
Economy, Helsinki, Finland.
Llewellyn D W Thomas ( llewellyn.thomas@imperial.
ac.uk) is a visiting professor in the Innovation and
Entrepreneurship Department of Imperial College
Business School, London, U.K.
Copyright held by the Authors.
Publication rights licensed to ACM. $15.00
Using complete patent data available for more than 100 years from
160 countries comprising 90 million
patents, we have shown that ICT patents are consistently more influential
than patents from other industrial
sectors. We used simple, iterative
metrics to support our findings using
the full lifetime of patents or shorter
time spans. Whereas other studies
have highlighted the importance of
ICT for productivity and economic
development, we have quantified the
direct influence of ICT inventions on
We emphasize the results obtained
through the PageRank approach because it most accurately measures the
influence of inventions. PageRank
highlights the role of specific ICT inventions in enabling the invention of
other influential technologies. With it,
ICT patents do not appear quite as influential as with the coarser methods
of descriptive statistics, but we still
find a statistically and economically
significant difference between ICT
patents and the patents from other
sectors. While the propensity for a
greater number of patents and patent
citation within the ICT sector may exaggerate the influence of ICT, we use
PageRank to capture “cumulative”
influence and still find ICT patents
have an outstanding effect on subsequent technological development.
Our findings thus complement and
Figure 4. Kernel densities for distributions of (left) top (1%) patent citations and (right)
Most cited patents (top 1%)