Europhys. Lett.
Volume 67, Number 3, August 2004
Page(s) 498 - 503
Section Interdisciplinary physics and related areas of science and technology
Published online 01 July 2004
Europhys. Lett., 67 (3), pp. 498-503 (2004)
DOI: 10.1209/epl/i2004-10070-4

Statistical properties of business firms structure and growth

K. Matia1, Dongfeng Fu1, S. V. Buldyrev1, F. Pammolli2, M. Riccaboni2 and H. E. Stanley1

1  Center for Polymer Studies and Department of Physics, Boston University Boston, MA 02215 USA
2  Facoltà di Economia, Università di Firenze and CERM Via Banchi di Sotto 55, 53100 Siena Italy

(Received 10 March 2004; accepted in final form 17 May 2004)

We analyze a database comprising quarterly sales of 55624 pharmaceutical products commercialized by 3939 pharmaceutical firms in the period 1992-2001. We study the probability density function (PDF) of growth in firms and product sales and find that the width of the PDF of growth decays with the sales as a power law with exponent $\beta=0.20\pm 0.01$. We also find that the average sales of products scales with the firm sales as a power law with exponent $\alpha=0.57\pm 0.02$. And that the average number products of a firm scales with the firm sales as a power law with exponent $\gamma=0.42\pm 0.02$. We compare these findings with the predictions of models proposed till date on growth of business firms.

89.90.+n - Other topics in areas of applied and interdisciplinary physics.
05.45.Tp - Time series analysis.
05.40.Fb - Random walks and Levy flights.

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