International environmental agreements when countries behave morally

In the game-theoretical literature on forming international environmental agreements (IEAs) countries use to be self-interested materialists and stable coalitions are small. This paper analyzes IEA games with identical countries that exhibit Kantian moral behavior. Kantians are concerned with doing the right thing which means that they take those actions and only those actions that they advocate all others take as well. Countries may behave morally with respect to both emissions (reduction) and membership in an IEA. If countries are emissions Kantians or membership Kantians the equilibrium of the IEA games is socially optimal. To model more realistic Kantian behavior, we define an emissions [membership] moralist as a country whose welfare is a weighted average of the welfare of an emissions [membership] Kantian and a materialist. The game with emissions moralists produces stable coalitions not larger than those in the standard game with materialists. The game with membership moralists yields stable coalitions that are increasing in the membership morality. The aggregate emissions decline if the degree of morality of either type of moralists increases. Finally, we characterize the equilibrium of an IEA game with moderate moralists with respect to both emissions and membership.