by Charles Blackorby, Walter Bossert and David Donaldson
revised August 2001
Prepared as Chapter 11 of the Handbook of Social Choice and Welfare K. Arrow, A. Sen and K. Suzumura, eds., Elsevier, Amsterdam
Charles Blackorby: University of British Columbia and GREQAM Walter Bossert: Universit´ de Montr´al and C.R.D.E. e e David Donaldson: University of British Columbia
* We thank Don Brown, Marc Fleurbaey, Philippe Mongin, John Weymark and a referee for comments and suggestions. Financial support through a grant from the Social Sciences and Humanities Research Council of Canada is gratefully acknowledged. August 20, 2001
This chapter provides a survey of utilitarian theories of justice. We review and discuss axiomatizations of utilitarian and generalized-utilitarian social-evaluation functionals in a welfarist framework. Section 2 introduces, along with some basic deﬁnitions, socialevaluation functionals. Furthermore, we discuss several information-invariance assumptions. In Section 3, the welfarism axioms unrestricted domain, binary independence of irrelevant alternatives and Pareto indiﬀerence are introduced and used characterize welfarist social evaluation. These axioms imply that there exists a single ordering of utility vectors that can be used to rank all alternatives for any proﬁle of individual utility functions. We call such an ordering a social-evaluation ordering, and we introduce several examples of classes of such orderings. In addition, we formulate some further basic axioms. Section 4 provides characterizations of generalized-utilitarian social-evaluation orderings, both in a static and in an intertemporal framework. Section 5 deals with the special case of utilitarianism. We review some known axiomatizations and, in addition, prove a new characterization result that uses an axiom we call incremental equity. In Section 6, we analyze generalizations of utilitarian principles to variable-population environments. We extend the welfarism theorem to a variable-population framework and provide a characterization of critical-level generalized utilitarianism. Section 7 provides an extension to situations in which the alternatives resulting from choices among feasible actions are not known with certainty. In this setting, we discuss characterization as well as impossibility results. Section 8 concludes. Journal of Economic Literature Classiﬁcation Numbers: D63, D71.
Keywords: Social Choice, Utilitarianism, Welfarism.
1. Introduction In A Theory of Justice, Rawls (1971) describes justice as “the ﬁrst virtue of social institutions” (p. 3) and identiﬁes “the primary subject of justice” as “the basic structure of society, or more exactly, the way in which the major social institutions distribute fundamental rights and duties and determine the division of advantages from social cooperation” (p. 7).1 The view of justice investigated in this chapter asserts that a just society is a good society: good for the individual people that comprise it. To implement such an approach to justice, the social good is identiﬁed and used to rank social alternatives. Of the alternatives that are feasible, given the constraints of human nature and history, the best is identiﬁed with justice. Even if the best alternative is not chosen, however, better ones are considered to be more just than worse ones. If societies are not perfectly just, therefore, social improvements can be recognized. Social choices are not made in isolation, however. Decisions made in a particular society aﬀect people in other parts of the world and people who are not yet born. In addition, both the number and identities of future people are inﬂuenced by choices made in the present. For that reason, principles that identify the social good are typically extended to rank complete histories of the world (or the universe if necessary) from remote past to distant future.2 The principle...