Self-interest, distributive justice, and the income distribution: A theoretical fragment based on St. Anselm's postulate

The Mertonian starting idea for this paper is St. Anselm's idea that the will has two inclinations: an affection for what is to the person's own advantage and an affection for justice. We show that in decision-making situations, where the individual must choose a course of action from among a set of alternatives, the individual, subject to the two inclinations and thus guided by the twin considerations of own good and the common good as he/she forms the preference orderings for the alternatives, is in one of three states: (i) the state of Harmony, defined by perfect coincidence of the orderings induced by the two criteria; (ii) the state of Conflict, defined by perfect reversal of the orderings; and (iii) the state of Ambiguity, defined by ordering-pairs which are neither identical nor exactly opposite. The most general result states that if the number of alternatives is two, then the individual is in either Harmony or Conflict; if, however, the number of alternatives exceeds two, then Ambiguity is also a possible outcome. We then apply the framework to the case of choosing an income distribution, letting the own-good and common-good criteria dictate orderings based on personal outcomes (such as own income or own income rank) and social outcomes (such as mean income or income inequality), respectively, and examining the relation between the two orderings in five families of probability distributions. In the special case where own good is an increasing function of own income and the common good is a decreasing function of income inequality, our results show that each society has a group in Harmony (the poorest group) and one additional group, either in Conflict or in Ambiguity. Finally, we speculate about the behavioral and social implications of the three states and their configurations in the population.