Interpersonal comparisons with or without formal welfarism CLAUDE D ’ ASPREMONT
Introduction Social Choice Theory, as a discipline devoted to the axiomatic study of collective mechanisms, can be divided into two broad fields. In one field, the main object is collective decision-making, and the acceptability of the resulting social state is fully determined by the justifiability of the decision procedure. The study of voting rules for political elections is the main domain of application in this field. As we will see, the results of such rules cannot always be acceptable in terms of justice and equity. In the other field, the main object is the evaluation of social states, individually as well as globally, on the basis of interpersonal comparisons of some kind, and Welfare Economics is the main domain of application. It is this part of Social Choice Theory that is intrinsically linked to ethics (to social ethics, more precisely) and to two basic ethical concepts, the right and the good. In that respect the relevant distinction in ethics is between deontological theories and teleological ones, the former giving priority to the right, the latter deriving the concept of rightness from a conception of the good. The predominant example of the teleological approach is classical utilitarianism and the associated concept of utility. But even within the utilitarian tradition, the term “utility” has received many different interpretations, so that the distinguishing mark of the utility approach to the evaluation of social states by an ethical observer is to assign to each member of the collectivity a uni-dimensional individual indicator. These indicators combine in various ways the “subjective” appreciation of the social states by each individual and their “objective” evaluation by the observer. Bentham introduced an interpersonally summable notion of utility based on the objective property of things to procure either pain or pleasure, but it is the subjective reinterpretation by J.S. Mill, for whom utility means “pleasure itself ” and “exemption of pain”, which has been retained (see the discussion in Mongin and d’Aspremont 1998). The modern treatment of utilitarianism as represented by Harsanyi (1955, 1977) Aggregation Theorem is based on von Neumann and Morgenstern (NM) utility theory. The criterion is expected utility computed from the individual NM-utility functions, but “corrected” for factual errors and “censored” for anti-social attitudes. Also, the criterion is applied to select the principles or the
rules that should orient individual actions, leaving some room to individual decisions (rule-utilitarianism instead of act-utilitarianism). The classic example of deontological ethics is Kant’s practical philosophy. Modern examples are Rawls’ Theory of Justice, claiming explicitly the priority of the right over the good, and Nozick’s Anarchy, State and Utopia and the anteriority attributed to individual property right and other natural rights. In fact the distinction between teleological and deontological theories is also akin to the opposition between freedom and happiness which is the unifying theme of the present volume in reference to Rawls’ (2000) distinction between a “liberalism of freedom” and a “liberalism of happiness” and his claim that “principles of political and civic freedoms” have priority over others. Rawls’ (1971) principles of justice are agreed upon in some original negotiation. In this negotiation, the representatives of the individual citizens are behind a “veil of ignorance”, meaning that all irrelevant personal features (including personal conceptions of the good) are ignored. The negotiators should agree on the distribution of different categories of “primary goods” as fundamental resources allocated to each person to promote his own conception of the good. The first two categories concern rights and have priority: (i) the basic liberties and (ii) the access to various occupations and functions. Also chosen behind this “veil of ignorance” is an “index of primary goods” defined as an objective indicator of the other categories of primary goods: (iii) powers and prerogatives; (iv) income and wealth; (v) the social bases of self-respect (the first two, liberties and access to occupations, are preliminarily and equally divided). If such an indicator can be called “utility” it is not in the sense of “happiness” or “preference satisfaction”. Desires (however intense) and tastes (however inexpensive) are not relevant per se. A similar view is represented by Sen’s (1992) notion of capabilities, that is the set of doings or “functionings” available to a person, leading to an “index of functionings”. What is at stake here, as in other theories concerned with opportunities (e.g. Roemer 1996), are the objectively defined conditions allowing individuals to exercise their freedom. In the following, we shall see that a unifying approach can be used to study the two kinds of theories, in particular by specifying what individual features should be considered as relevant to evaluate and compare social states. This specification is obtained through so-called “invariance axioms”, restricting the measurability and the comparability properties of individual evaluation profiles, and leading, together with other axioms, to different social rankings. In the next section these other axioms will be sufficient to define a simplified framework, which we call “formal welfarism”, since it is open to different interpretations of the technical notion of utility (including the one given in terms of primary goods), whereas the original framework of “welfarism” referred to the standard interpretation of utility in terms of happiness or desire-fulfillment. The section “Interpersonal comparisons through scoring methods” will introduce another kind of interpersonal comparisons which is based on some adequately constructed intermediate indicators (the scores), respecting and complementing standard individual utilities as measures of preference satisfaction.