English

Uniform propagation of chaos for a dollar exchange econophysics model

Probability 2025-01-15 v1

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.

Keywords

Cite

@article{arxiv.2212.08289,
  title  = {Uniform propagation of chaos for a dollar exchange econophysics model},
  author = {Roberto Cortez and Fei Cao},
  journal= {arXiv preprint arXiv:2212.08289},
  year   = {2025}
}

Comments

17 pages, 6 figures. arXiv admin note: text overlap with arXiv:2208.05629