Utilitarianism and prioritarianism I

Economics and Philosophy 24(1) (2008): 1–33, 2008

A natural formalization of the priority view is presented which results from adding expected utility theory to the main ideas of the priority view. The result is ex post prioritarianism. But ex post prioritarianism entails that in a world containing just one person, it is sometimes better for that person to do what is strictly worse for herself. This claim may appear to be implausible. But the deepest objection to ex post prioritarianism has to do with meaning: ex post prioritarianism is not a genuine alternative to utilitarianism in the first place. By contrast, ex ante prioritarianism is defensible. But its motivation is very different from the usual rationales offered for the priority view. Given their hostility to egalitarianism, most supporters of the priority view have not provided reasons to reject utilitarianism.

Prioritarianism is a distinctive moral view. Outcomes are ranked according to the sum of concavely transformed well-being numbers—by contrast with utilitarianism, which simply adds up well-being. Thus, unlike utilitarians, prioritarians give extra moral weight to the well-being of the worse off. Unlike egalitarians, prioritarians endorse an axiom of person-separability: the ranking of outcomes is independent of the well-being levels of unaffected individuals. Unlike sufficientists, who give no priority to the worse-off if their well-being exceeds a “sufficiency” threshold, prioritarians always favor the worse-off in conflicts with those at higher well-being levels. Derek Parfit is prioritarianism’s most famous proponent. We have also defended prioritarianism. Not everyone is persuaded. Prioritarianism has been vigorously criticized, from a variety of perspectives, most visibly by John Broome, Campbell Brown, Lara Buchak, Roger Crisp, Hilary Greaves, David McCarthy, Michael Otsuka, Ingmar Persson, Shlomi Segall, Larry Temkin, and Alex Voorhoeve. In this Article, we answer the critics.

Erkenntnis, 1994

The Economic Journal, 2018

We provide a microfoundation for a weighted utilitarian social welfare function that re ‡ects common moral intuitions about interpersonal comparisons of utilities. If utility is only ordinal in the usual microeconomic sense, interpersonal comparisons are meaningless. Nonetheless, economics often adopts utilitarian welfare functions, assuming that comparable utility functions can be calibrated using information beyond consumer choice data. We show that consumer choice data alone are su¢ cient. As suggested by Edgeworth (1881), just noticeable di¤erences provide a common unit of measure for interpersonal comparisons of utility di¤erences. We prove that a simple monotonicity axiom implies a weighted utilitarian aggregation of preferences, with weights proportional to individual jnd's. We thank Paul Milgrom, Philippe Mongin, Uzi Segal, and David Schmeidler for comments and discussions. We are particularly grateful to Luigi Balletta, Ludovic Renou, three anonymous referees, and the editor for comments on earlier versions of this paper and for important references. Gilboa gratefully acknowledges support from ISF Grants 204/13, 704/15, the Foerder Foundation, ERC Grant 269754, and Investissements d'Avenir ANR-11-IDEX-0003 / Labex ECODEC No.

Exploring Practical Philosophy: From Action to Values, Aldershot: Ashgate, 2001

This paper takes its departure from the Interpersonal Addition Theorem. The theorem, by John Broome (1991), is a re-formulation of the classical result by Harsanyi (1955). It implies that, given some seemingly mild assumptions, the overall utility of an uncertain prospect can be seen as the sum of its individual utilities. In sections 1 and 2, I discuss the theorem’s connection with utilitarianism and in particular the extent to which this theorem still leaves room for the Priority View. According to the latter, the utilitarian approach needs to be modified: Benefits to the worse off should count for more, overall, than the comparable benefits to the better off (cf. Parfit 1995 [1991]). Broome (1991) and Jensen (1996) have argued that the Priority View cannot be seen as a plausible competitor to utilitarianism: Given the addition theorem, prioritarianism should be rejected for measurement-theoretical reasons. I suggest that this difficulty is spurious: The proponents of the Priority View would be well advised, on independent grounds, to reject one of the basic assumptions on which the addition theorem is based, the so-called Principle of Personal Good for uncertain prospects. According to the Principle of Personal Good, one prospect is better than another if it is better for everyone or at least better for some and worse for none. That the Priority View, as I read it, rejects this welfarist intuition may be surprising. Isn’t welfarism a common ground for prioritarians and utilitarians? Still, as I argue, this welfarist common ground is better captured by a restricted Principle of Personal Good that is valid for *outcomes*, but not necessarily for uncertain prospects. We obtain this surprising result if we take the priority weights imposed by prioritarians to be relevant only to *moral*, but not to *prudential*, evaluations of prospects. This makes it possible for a prospect to be morally better even though it is worse (prudentially) for everyone concerned. The proposed interpretation of the Priority View thus drives a sharp wedge between prudence and morality.

Social Science Research Network, 2017

We provide a microfoundation for a weighted utilitarian social welfare function that re ‡ects common moral intuitions about interpersonal comparisons of utilities. If utility is only ordinal, interpersonal comparisons are meaningless. Nonetheless, economics often adopts utilitarian welfare functions, assuming that comparable utility functions can be calibrated using information beyond consumer choice data. We show that consumer choice data alone are su¢cient. As suggested by Edgeworth (1881), just noticeable di¤erences provide a common unit of measure for interpersonal comparisons of utility di¤erences. We prove that a simple monotonicity axiom implies a weighted utilitarian aggregation of preferences, with weights proportional to individual jnd's. We thank Paul Milgrom, Philippe Mongin, Uzi Segal, and David Schmeidler for comments and discussions. We are particularly grateful to Luigi Balletta, Ludovic Renou, and an anonymous referee for comments on earlier versions of this paper and for important references. Gilboa gratefully acknowledges support from ISF Grants 204/13, 704/15, the Foerder Foundation, and ERC Grant 269754.

SSRN Electronic Journal, 2000

Harsanyi invested his Aggregation Theorem and Impartial Observer Theorem with deep utilitarian sense, but Sen redescribed them as "representation theorems" with little ethical import. This negative view has gained wide acquiescence in economics. Against it, we support the utilitarian interpretation by a novel argument relative to the Aggregation Theorem. We suppose that a utilitarian observer evaluates non-risky alternatives by the sum of individual utilities and investigate his von Neumann-Morgenstern (VNM) preference on risky alternatives. Adding some technical assumptions to Harsanyi's, we conclude that (i) this observer would use the utility sum as a VNM utility function, and crucially, (ii) any social observer would evaluate both risky and non-risky alternatives in terms of a weighted utility sum.

Utilitas, 2015

A simple hedonistic theory allowing for interpersonal comparisons of happiness is taken for granted in this article. The hedonistic theory is used to compare utilitarianism, urging us to maximize the sum total of happiness, with prioritarianism, urging us to maximize a sum total of weighed happiness. It is argued with reference to a few thought experiments that utilitarianism is, intuitively speaking, more plausible than prioritarianism. The problem with prioritarianism surfaces when prudence and morality come apart.

2021

In this paper, we reexamine the axiomatic foundation of prioritarianism – a distributive ethical view originating from Derek Parfit (1991) that claims that “[b]enefiting people matters more the worse off these people are” (Parfit 1991: 19). In previous work, prioritarianism has been characterized by the following five axioms: Pigou-Dalton, Separability, Anonymity, Pareto, and Continuity. Among these axioms, many scholars have regarded Pigou-Dalton (along with Separability) as the key defining feature that distinguishes prioritarianism from other continuous welfarist views. We disagree: not because we think the Pigou-Dalton principle is incompatible with prioritarianism (it is), but because the Pigou-Dalton principle fails to distinguish prioritarianism from telic egalitarianism, which is what motivated Parfit to present prioritarianism as an alternative view of distributive ethics in the first place. Instead, we propose a new axiom, which we call “Priority,” which clearly expresses Parfit’s original prioritarian idea, as the main defining property of prioritarianism, and offer a new axiomatic characterization of prioritarianism in terms of this new axiom. We then analyze the precise logical relationships between Priority and the other axioms. Finally, we explore the important issue of measurability and interpersonal comparison of well-being in relation to prioritarianism. There have criticisms that the prioritarian social welfare function may not satisfy some information invariance property with respect to measurability and interpersonal comparability of well-being. It turns out that, compared to other social welfare orderings (such as utilitarianism, maximin, leximin, the general Gini ordering, etc.), prioritarianism may require a stronger well-being measure (viz., a translation-scale or a ratio-scale) than a cardinal measure with full interpersonal comparability to retain its normative and theoretical significance. From such observations, we specify the class of prioritarian social welfare functions free from this criticism.