B. de Bruyne 1 J. Randon-FurlingS. Redner
B. de Bruyne, J. Randon-Furling, S. Redner. A tale of two (and more) altruists. Journal of Statistical Mechanics: Theory and Experiment, IOP Publishing, 2021, 2021 (10), pp.103405. ⟨10.1088/1742-5468/ac2906⟩. ⟨hal-03390680⟩
We introduce a minimalist dynamical model of wealth evolution and wealth sharing among $N$ agents as a platform to compare the relative merits of altruism and individualism. In our model, the wealth of each agent independently evolves by diffusion. For a population of altruists, whenever any agent reaches zero wealth (that is, the agent goes bankrupt), the remaining wealth of the other $N-1$ agents is equally shared among all. The population is collectively defined to be bankrupt when its total wealth falls below a specified small threshold value. For individualists, each time an agent goes bankrupt (s)he is considered to be « dead » and no wealth redistribution occurs. We determine the evolution of wealth in these two societies. Altruism leads to more global median wealth at early times; eventually, however, the longest-lived individualists accumulate most of the wealth and are richer and more long lived than the altruists.
- 1. LPTMS – Laboratoire de Physique Théorique et Modèles Statistiques