9 de febrero de 2018

A game theoretic model of wealth distribution

J. P. Pinasco, M. Rodríguez Cartabia, N. Saintier, Dyn. Games Appl.  (2018)

In this work we consider an agent based model in order to studythe wealth distribution problem where the interchange is determined with a symmetric zero sum game. Simultaneously, the agents update their way of play trying to learn the optimal one. Here, the agents use mixed strategies. We study this model using both simulations and theoretical tools. We derive the equations for the learning mechanism, and we show that the mean strategy of the population satis es an equation close to the classical replicator equation. Concerning the wealth distribution, there are two interesting situations depending on the equilibrium of the game. If the equilibrium is a pure strategy, the wealth distribution is xed after some transient time, and those players which are close to optimal strategy are richer. When the game has an equilibrium in mixed strategies, the stationary wealth distribution is close to a Gamma distribution with variance depending on the coe cients of the game matrix. We compute theoretically their second moment in this case.