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arXiv · 2212.08289

Uniform propagation of chaos for a dollar exchange econophysics model

Roberto Cortez·Fei Cao
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Abstract

We study the poor-biased model for money exchange introduced in [2]: agents are being randomly picked at a rate proportional to their current wealth, and then the selected agent gives a dollar to another agent picked uniformly at random. Simulations of a stochastic system of finitely many agents as well as a rigorous analysis carried out in [2,16] suggest that, when both the number of agents and time become large enough, the distribution of money among the agents converges to a Poisson distribution. In this manuscript, we establish a uniform-in-time propagation of chaos result as the number of agents goes to infinity, which justifies the validity of the mean-field deterministic infinite system of ordinary differential equations as an approximation of the underlying stochastic agent-based dynamics.

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Roberto Cortez, Fei Cao. 2022-12-16. Uniform propagation of chaos for a dollar exchange econophysics model. https://doi.org/10.1017/s0956792524000184

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