Random walk to innovation: why productivity follows a power law
In this paper we propose a mechanism generating innovations with productivity distributed according to a power law. We assume that knowledge creation occurs as new ideas are produced from combinations of existing ideas. The productivity of an innovation is determined by an unobservable intrinsic component as well as by the productivity of the parent ideas and their parents, thus generating a network of spillovers. The second important feature is that the innovator has no global information on the network of parenthood links across ideas but has acces to local knowledge, as for example the list of cited references in a patent. The optimal behaviour of the innovator is to "walk randomly" through the network of "citations" as this algorithm leads to selecting highly connected parent nodes. We show that the distribution of productivity resulting from this optimal behaviour follows a power law. The intuition behind the result is that the innovator focuses his efforts on strengthening local spillovers because he has no command on the other sources of productivity. When this process of innovation is imbedded in a model a la Kortum (1997) balanced growth of output is generated.
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- Xavier Gabaix, 2009.
"Power Laws in Economics and Finance,"
Annual Review of Economics,
Annual Reviews, vol. 1(1), pages 255-294, 05.
- Martin L. Weitzman, 1998.
The Quarterly Journal of Economics,
MIT Press, vol. 113(2), pages 331-360, May.
- Weitzman, Martin L., 1998. "Recombinant Growth," Scholarly Articles 3708468, Harvard University Department of Economics.
- Martin L. Weitzman, 1995. "Recombinant Growth," Harvard Institute of Economic Research Working Papers 1722, Harvard - Institute of Economic Research.
- Cordoba, Juan Carlos, 2010.
"On the Distribution of City Sizes,"
Staff General Research Papers
32121, Iowa State University, Department of Economics.
- Luttmer, Erzo G.J., 2012.
"Technology diffusion and growth,"
Journal of Economic Theory,
Elsevier, vol. 147(2), pages 602-622.
- James D. Adams & Adam B. Jaffe, 1996.
"Bounding the Effects of R&D: An Investigation Using Matched Establishment-Firm Data,"
RAND Journal of Economics,
The RAND Corporation, vol. 27(4), pages 700-721, Winter.
- James D. Adams & Adam B. Jaffe, 1996. "Bounding the Effects of R&D: An Investigation Using Matched Establishment-Firm Data," NBER Working Papers 5544, National Bureau of Economic Research, Inc.
- Peretto, P. & Smulders, J.A., 2002.
"Technological distance, growth and scale effects,"
Other publications TiSEM
bdce08a7-4ad9-4427-a99e-f, School of Economics and Management.
- Armen A. Alchian, 1950. "Uncertainty, Evolution, and Economic Theory," Journal of Political Economy, University of Chicago Press, vol. 58, pages 211.
- Ola Olsson, 2005. "Technological Opportunity and Growth," Journal of Economic Growth, Springer, vol. 10(1), pages 31-53, 01.
- Charles I. Jones, 2005.
"The Shape of Production Functions and the Direction of Technical Change,"
The Quarterly Journal of Economics,
MIT Press, vol. 120(2), pages 517-549, May.
- Charles I. Jones, 2004. "The Shape of Production Function and the Direction of Technical Change," NBER Working Papers 10457, National Bureau of Economic Research, Inc.
- Xavier Gabaix, 1999. "Zipf'S Law For Cities: An Explanation," The Quarterly Journal of Economics, MIT Press, vol. 114(3), pages 739-767, August.
- Philip Auerswald & Stuart Kauffman & Jose Lobo & Karl Shell, 1998.
"The Production Recipes Approach to Modeling Technological Innovation: An Application to Learning By Doing,"
98-11-100, Santa Fe Institute.
- Auerswald, Philip & Kauffman, Stuart & Lobo, Jose & Shell, Karl, 2000. "The production recipes approach to modeling technological innovation: An application to learning by doing," Journal of Economic Dynamics and Control, Elsevier, vol. 24(3), pages 389-450, March.
- Saramäki, Jari & Kaski, Kimmo, 2004. "Scale-free networks generated by random walkers," Physica A: Statistical Mechanics and its Applications, Elsevier, vol. 341(C), pages 80-86.
- Aghion, Philippe & Howitt, Peter, 1992.
"A Model of Growth through Creative Destruction,"
Econometric Society, vol. 60(2), pages 323-51, March.
- Aghion, P. & Howitt, P., 1990. "A Model Of Growth Through Creative Destruction," DELTA Working Papers 90-12, DELTA (Ecole normale supérieure).
- Aghion, P. & Howitt, P., 1989. "A Model Of Growth Through Creative Destruction," UWO Department of Economics Working Papers 8904, University of Western Ontario, Department of Economics.
- Philippe Aghion & Peter Howitt, 1990. "A Model of Growth Through Creative Destruction," NBER Working Papers 3223, National Bureau of Economic Research, Inc.
- Aghion, P. & Howitt, P., 1989. "A Model Of Growth Through Creative Destruction," Working papers 527, Massachusetts Institute of Technology (MIT), Department of Economics.
- Cline, D. B. H. & Samorodnitsky, G., 1994. "Subexponentiality of the product of independent random variables," Stochastic Processes and their Applications, Elsevier, vol. 49(1), pages 75-98, January.
- Aghion, Philippe & Howitt, Peter, 1992. "A Model of Growth Through Creative Destruction," Scholarly Articles 12490578, Harvard University Department of Economics.
- Kelly, Morgan, 2001. " Linkages, Thresholds, and Development," Journal of Economic Growth, Springer, vol. 6(1), pages 39-53, March.
- Jovanovic, Boyan, 1982. "Selection and the Evolution of Industry," Econometrica, Econometric Society, vol. 50(3), pages 649-70, May.
- Olsson, Ola, 2000. " Knowledge as a Set in Idea Space: An Epistemological View on Growth," Journal of Economic Growth, Springer, vol. 5(3), pages 253-75, September.
- Erzo G. J. Luttmer, 2007. "Selection, Growth, and the Size Distribution of Firms," The Quarterly Journal of Economics, MIT Press, vol. 122(3), pages 1103-1144, 08.
- Matthew O. Jackson & Brian W. Rogers, 2007. "Meeting Strangers and Friends of Friends: How Random Are Social Networks?," American Economic Review, American Economic Association, vol. 97(3), pages 890-915, June.
- Samuel S. Kortum, 1997. "Research, Patenting, and Technological Change," Econometrica, Econometric Society, vol. 65(6), pages 1389-1420, November.
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