The Relevance of Utilitarianism

Rational Interaction, 1992

Harsanyi's utilitarian theorem states that the social welfare function is the weighted sum of individuals' utility functions if: (i) society maximizes expected social welfare; (ii) individuals maximize expected utility; (iii) society is indifferent between two probability distributions over social states whenever all individuals are. After giving a simpler proof, an alternative axiomatic foundation for Vickrey-Harsanyi utilitarianism is provided. By making using an extended version of Harsanyi's concept of a player's "type" in the theory of games with incomplete information, the problem of forming social objectives when there is incomplete information can also be resolved, at least in principle.

Econometrica, 2010

We provide an axiomatization of generalized utilitarian social welfare functions in the context of Harsanyi's impartial observer theorem. To do this, we reformulate Harsanyi's problem such that lotteries over identity (accidents of birth) and lotteries over outcomes (life chances) are independent. We show how to accommodate (…rst) Diamond's critique concerning fairness and Pattanaik's critique concerning di¤ering attitudes toward risk. In each case, we show what separates them from Harsanyi by showing what extra axioms return us to Harsanyi. Thus we provide two new axiomatizations of Harsanyi's utilitarianism..

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.

Utilitas, 2016

Harsanyi claimed that his Aggregation and Impartial Observer Theorems provide a justification for utilitarianism. This claim has been strongly resisted, notably by Sen and Weymark, who argue that while Harsanyi has perhaps shown that overall good is a linear sum of individuals' von Neumann-Morgenstern utilities, he has done nothing to establish any connection between the notion of von Neumann-Morgenstern utility and that of well-being, and hence that utilitarianism does not follow. The present article defends Harsanyi against the Sen-Weymark critique. I argue that, far from being a term with precise and independent quantitative content whose relationship to von Neumann-Morgenstern utility is then a substantive question, terms such as 'well-being' suffer (or suffered) from indeterminacy regarding precisely which quantity they refer to. If so, then (on the issue that this article focuses on) Harsanyi has gone as far towards defending 'utilitarianism in the original sense' as could coherently be asked.

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.

Journal of Mathematical Economics, 87 (2020) 77-113, 2020

We give two social aggregation theorems under conditions of risk, one for constant population cases, the other an extension to variable populations. Intra and interpersonal welfare comparisons are encoded in a single ‘individual preorder’. The theorems give axioms that uniquely determine a social preorder in terms of this individual preorder. The social preorders described by these theorems have features that may be considered characteristic of Harsanyi-style utilitarianism, such as indifference to ex ante and ex post equality. However, the theorems are also consistent with the rejection of all of the expected utility axioms, completeness, continuity, and independence, at both the individual and social levels. In that sense, expected utility is inessential to Harsanyi-style utilitarianism. In fact, the variable population theorem imposes only a mild constraint on the individual preorder, while the constant population theorem imposes no constraint at all. We then derive further results under the assumption of our basic axioms. First, the individual preorder satisfies the main expected utility axiom of strong independence if and only if the social preorder has a vector-valued expected total utility representation, covering Harsanyi’s utilitarian theorem as a special case. Second, stronger utilitarian-friendly assumptions, like Pareto or strong separability, are essentially equivalent to strong independence. Third, if the individual preorder satisfies a ‘local expected utility’ condition popular in non-expected utility theory, then the social preorder has a ‘local expected total utility’ representation. Fourth, a wide range of non-expected utility theories nevertheless lead to social preorders of outcomes that have been seen as canonically egalitarian, such as rank-dependent social preorders. Although our aggregation theorems are stated under conditions of risk, they are valid in more general frameworks for representing uncertainty or ambiguity.

Journal of Political Economy, 2004

Social Choice and Welfare, 1989

Part I of this paper offers a novel result in social choice theory by extending Harsanyi's well-known utilitarian theorem into a "multi-profile" context. Harsanyi was contented with showing that if the individuals' utilities u~ are von Neumann-Morgenstern, and if the given utility u of the social planner is VNM as well, then the Pareto indifference rule implies that u is affine in terms of the u~. We provide a related conclusion by considering u as functionally dependent on the ul, through a suitably restricted "social welfare functional"

After reviewing the compelling case for separability ('social welfare is a separable function of individual utilities'), an argument is advanced for utilitarianism (defined as 'social welfare is the unweighted sum of individual utilities'). Basically, a compelling individualism-type axiom leads us to (social welfare as an) unweighted sum (of individual utilities), given separability.

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.