eprintid: 646 rev_number: 16 eprint_status: archive userid: 2 dir: disk0/00/00/06/46 datestamp: 2011-06-30 14:26:16 lastmod: 2013-11-21 13:03:15 status_changed: 2011-06-30 14:26:16 type: article metadata_visibility: show item_issues_count: 0 creators_name: Pammolli, Fabio creators_name: Buldyrev, Sergey V. creators_name: Riccaboni, Massimo creators_name: Yamasaki, Kazuko creators_name: Fu, Dongfeng creators_name: Matia, Kaushik creators_name: Stanley, H. Eugene creators_id: f.pammolli@imtlucca.it creators_id: creators_id: massimo.riccaboni@imtlucca.it creators_id: creators_id: creators_id: creators_id: title: A generalized preferential attachment model for business firms growth rates: II. Mathematical treatment ispublished: pub subjects: HB subjects: HG subjects: QC divisions: EIC full_text_status: none note: PACS. 89.75.Fb Structures and organization in complex systems - 89.65.Gh Economics; econophysics, financial markets, business and management abstract: We present a preferential attachment growth model to obtain the distribution P(K) of number of units K in the classes which may represent business firms or other socio-economic entities. We found that P(K) is described in its central part by a power law with an exponent ϕ = 2+b/(1-b) which depends on the probability of entry of new classes, b. In a particular problem of city population this distribution is equivalent to the well known Zipf law. In the absence of the new classes entry, the distribution P(K) is exponential. Using analytical form of P(K) and assuming proportional growth for units, we derive P(g), the distribution of business firm growth rates. The model predicts that P(g) has a Laplacian cusp in the central part and asymptotic power-law tails with an exponent ζ = 3. We test the analytical expressions derived using heuristic arguments by simulations. The model might also explain the size-variance relationship of the firm growth rates. date: 2007 date_type: published publication: The European Physical Journal B volume: 57 number: 2 publisher: Springer pagerange: 131-138 id_number: 10.1140/epjb/e2007-00165-8 refereed: TRUE issn: 1434-6028 official_url: http://dx.doi.org/10.1140/epjb/e2007-00165-8 citation: Pammolli, Fabio and Buldyrev, Sergey V. and Riccaboni, Massimo and Yamasaki, Kazuko and Fu, Dongfeng and Matia, Kaushik and Stanley, H. Eugene A generalized preferential attachment model for business firms growth rates: II. Mathematical treatment. The European Physical Journal B, 57 (2). pp. 131-138. ISSN 1434-6028 (2007)