%0 Journal Article
%@ 0295-5075
%A Pammolli, Fabio
%A Matia, Kaushik
%A Fu, Dongfeng
%A Buldyrev, Sergey V.
%A Riccaboni, Massimo
%A Stanley, H. Eugene
%D 2004
%F eprints:650
%I EDP Sciences
%J EPL (Europhysics Letters)
%N 3
%P 498
%T Statistical properties of business firms structure and growth
%U http://eprints.imtlucca.it/650/
%V 67
%X 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 β = 0.20 ± 0.01. We also find that the average sales of products scales with the firm sales as a power law with exponent α = 0.57 ± 0.02. And that the average number products of a firm scales with the firm sales as a power law with exponent γ = 0.42 ± 0.02. We compare these findings with the predictions of models proposed till date on growth of business firms.
%Z   PACS:  05.45.Tp Time series analysis        05.40.Fb Random walks and Levy flights        89.90.+n Other topics in areas of applied and interdisciplinary physics (restricted to new topics in section 89)