Three Barriers to Kantian Cooperation under Inequality

Multiplicative Kantian equilibrium has been proposed as a solution to inefficiency in social dilemmas, yet its emergence and stability are associated with a number of coordination and distributional difficulties. Drawing on a simple model of voluntary public good provision with two agents who differ in their initial endowments and have logarithmic preferences, this paper identifies three barriers that arise sequentially when unequal agents attempt to adopt Kantian cooperation voluntarily. The model compares Nash equilibrium with multiplicative Kantian equilibrium under two different parametrizations: one in which the strategic variable is contributions to the public good, and another in which it is private consumption. First, we show that the transition from Nash equilibrium to contribution space Kantian behavior is not always a Pareto improvement: under sufficiently high inequality, the poor agent may prefer the Nash outcome. This barrier can be mitigated by preliminary redistribution. Second, even when agents are willing to cooperate, the choice of a parametrization of the strategic space becomes a distributional issue: different ways of scaling actions lead to different distributive consequences and create a conflict of interest between agents. Third, if the chosen parametrization admits a continuum of Pareto efficient outcomes, an additional coordination problem arises-agreeing on a specific point on the Pareto frontier. The paper reconstructs these barriers as a three step coordination problem in which expectations about later stages affect willingness of agents to enter Kantian cooperation at the outset. On the basis of the results obtained, a program for further formal research is outlined. The findings contribute to understanding the conditions under which Kantian cooperation can be voluntarily adopted and sustainably maintained.