A Free and Fair Economy: A Game of Justice and Inclusion

TL;DR

This paper explores how principles of justice and inclusion influence the existence and uniqueness of equilibria in non-cooperative economies, integrating normative fairness into game theory with broad applications.

Contribution

It introduces a framework linking distributive justice principles to equilibrium existence and uniqueness in non-cooperative economies, including social justice and redistribution mechanisms.

Findings

Distributive justice principles ensure equilibrium existence in free economies.

Violations of fairness principles can prevent equilibrium existence.

Technological monotonicity guarantees equilibrium uniqueness and efficiency.

Abstract

Frequent violations of fair principles in real-life settings raise the fundamental question of whether such principles can guarantee the existence of a self-enforcing equilibrium in a free economy. We show that elementary principles of distributive justice guarantee that a pure-strategy Nash equilibrium exists in a finite economy where agents freely (and non-cooperatively) choose their inputs and derive utility from their pay. Chief among these principles is that: 1) your pay should not depend on your name, and 2) a more productive agent should not earn less. When these principles are violated, an equilibrium may not exist. Moreover, we uncover an intuitive condition -- technological monotonicity -- that guarantees equilibrium uniqueness and efficiency. We generalize our findings to economies with social justice and inclusion, implemented in the form of progressive taxation and redistribution, and guaranteeing a basic income to unproductive agents. Our analysis uncovers a new class of strategic form games by incorporating normative principles into non-cooperative game theory. Our results rely on no particular assumptions, and our setup is entirely non-parametric. Illustrations of the theory include applications to exchange economies, surplus distribution in a firm, contagion and self-enforcing lockdown in a networked economy, and bias in the academic peer-review system. Keywords: Market justice; Social justice; Inclusion; Ethics; Discrimination; Self-enforcing contracts; Fairness in non-cooperative games; Pure strategy Nash equilibrium; Efficiency. JEL Codes: C72, D30, D63, J71, J38