Pammolli, Fabio and Yamasaki, Kazuko and Matia, Kaushik and Buldyrev, Sergey V. and Fu, Dongfeng and Riccaboni, Massimo and Stanley, H. Eugene Preferential attachment and growth dynamics in complex systems. Physical Review E, 74 (3). 035103(R)8. ISSN 1539-3755 (2006)Full text not available from this repository.
Complex systems can be characterized by classes of equivalency of their elements defined according to system specific rules. We propose a generalized preferential attachment model to describe the class size distribution. The model postulates preferential growth of the existing classes and the steady influx of new classes. According to the model, the distribution changes from a pure exponential form for zero influx of new classes to a power law with an exponential cut-off form when the influx of new classes is substantial. Predictions of the model are tested through the analysis of a unique industrial database, which covers both elementary units (products) and classes (markets, firms) in a given industry (pharmaceuticals), covering the entire size distribution. The model’s predictions are in good agreement with the data. The paper sheds light on the emergence of the exponent τ≈2 observed as a universal feature of many biological, social and economic problems.
|Additional Information:||PACS: 89.75.Fb, 05.70.Ln, 89.75.Da, 89.65.Gh|
|Subjects:||H Social Sciences > HB Economic Theory
H Social Sciences > HD Industries. Land use. Labor
Q Science > QC Physics
R Medicine > RM Therapeutics. Pharmacology
|Research Area:||Economics and Institutional Change|
|Depositing User:||Users 2 not found.|
|Date Deposited:||01 Jul 2011 08:58|
|Last Modified:||31 Aug 2011 14:40|
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