Wealth Dynamics on Complex Networks

Physica A: Statistical Mechanics and its Applications, Volume 338, Issues 1-2, 1 July 2004, Pages 113-118. Proceedings of the conference A Nonlinear World: the Real World, 2nd International Conference on Frontier Science, Pavia (Italy) We study a model of wealth dynamics [Bouchaud and M\'ezard 2000, \emph{Physica A} \textbf{282}, 536] which mimics transactions among economic agents. The outcomes of the model are shown to depend strongly on the topological properties of the underlying transaction network. The extreme cases of a fully connected and a fully disconnected network yield power-law and log-normal forms of the wealth distribution respectively. We perform numerical simulations in order to test the model on more complex network topologies. We show that the mixed form of most empirical distributions (displaying a non-smooth transition from a log-normal to a power-law form) can be traced back to a heterogeneous topology with varying link density, which on the other hand is a recently observed property of real networks.