Aggregation of coarse preferences

We consider weak preference orderings over a set A _n of n alternatives. An individual preference is of refinement?≤n if it first partitions A _n into ? subsets of `tied' alternatives, and then ranks these subsets within a linear ordering. When ?<n, preferences are coarse. It is shown that, if the refinement of preferences does not exceed ?, a super majority rule (within non-abstaining voters) with rate 1− 1/? is necessary and sufficient to rule out Condorcet cycles of any length. It is argued moreover how the coarser the individual preferences, (1) the smaller the rate of super majority necessary to rule out cycles `in probability'; (2) the more probable the pairwise comparisons of alternatives, for any given super majority rule. Received: 29 June 1999/Accepted: 25 February 2000     

Ranking opportunity sets: An approach based on the preference for flexibility

We describe a criterion to evaluate subsets of a finite set of alternatives which are considered as opportunity sets. The axioms for set comparison are motivated within the preference for flexibility framework. We assume the preference over the universal set of alternatives to be made of two disjoint binary relations. The result is the axiomatic characterization of a procedure which is formally similar to the leximax ordering, but in our case it incorporates the presence of some uncertainty about the decision-maker final tastes. Received: 20 January 1999/Accepted: 20 October 1999     

Opportunity sets and individual well-being

 An opportunity set ranking rule assigns an ordering of opportunity sets to each individual utility function (defined on the universal set of alternatives) within the domain of this rule. Using an axiomatic approach, this paper characterizes a general class of opportunity set ranking rules which are based on the utilities associated with the elements of an opportunity set. It is argued that the addition of an alternative to a given opportunity set is not necessarily desirable in terms of overall well-being, and this position is reflected in replacing a commonly used monotonicity axiom with an alternative condition. Received: 15 May 1995/Accepted: 14 December 1995     

An informationally parsimonious impartial observer theorem

In Harsanyi's impartial observer theorem, an impartial observer determines a social ordering of the lotteries on the set of social alternatives based on a sympathetic but impartial concern for all individuals in society. This ordering is derived from a more primitive ordering on the set of all extended lotteries. An extended lottery is a lottery which determines both the observer's personal identity and the social alternative. We establish a version of Harsanyi's theorem in which the observer is only required to have preferences on the extended lotteries in which there is an equal chance of being any person in society. Received: 19 June 1996 / Accepted: 30 December 1996     

An axiomatic characterization of the lexicographic maximin extension of an ordering over a set to the power set

The lexicographic maximin extension of an ordering is an important and widely used tool in social choice theory. We provide an axiomatization of it by means of five axioms. When the basic ordering is linear the following four (independent) axioms are sufficient: (1) Gärdenfors principle; (2) Neutrality; (3) Strong Fishburn monotonicity; and (4) Extension. Our result may also have applications in the theory of individual choice under uncertainty.     

ON BECOMING DISABLED AND ARTICULATING ALTERNATIVES

The topic of this article is the ordering of disability. The question is how people become, and are made, disabled. This is linked with a further question about how to investigate and represent differences such as those between ability and disability. How can studies that aim to contribute to opening up and remaking the conditions of possibility for disability avoid reproducing the same differences and distributions of power and agency? Indeed, disability studies have contributed to denaturalizing ability as well as disability. Many of these studies owe much to genealogical approaches focusing on the descent, regulation, and generative power of discourse. But then the problematic inference is drawn that this discourse imposes itself to order how people perceive and think, materializes in bodies and practices, and does so in a coherent manner. The objective in this article is to pursue a different approach that investigates ordering in practice, brings out the existing alternatives and explores the possibilities for articulating these. For this endeavour, the author mobilizes a specific strand of Foucauldian work and reworkings of it in science and technology studies. Drawing on a study of life after road traffic accidents in Norway, this article explores the following: how disability becomes enacted in everyday practices; the character of the modes of ordering that emerge in these practices; how this ordering is achieved; and the nature of the relations and interferences between these ways of becoming disabled. The argument is that in practice people slip and move between multiple modes of ordering that co-exist, are partially related in complex ways, and even folded into each other. Finally, the article considers the relation between openness and multiplicity – and their study – in view of possibilities for articulating alternatives.     

Axiomatic derivation of scoring rules without the ordering assumption

Earlier derivations of scoring rules, by Smith (1973) and Young (1975), assumed that a voter can express only a rank ordering of the alternatives on his or her ballot. This paper shows that scoring rules can be derived without this ordering assumption. It is shown that a voting rule must be a scoring rule if it satisfies three basic axioms: reinforcement, overwhelming majorities, and neutrality. Other range and nonreversal axioms are also discussed.     

Choosing subsets: a size-independent probabilistic model and the quest for a social welfare ordering

“Subset voting” denotes a choice situation where one fixed set of choice alternatives (candidates, products) is offered to a group of decision makers, each of whom is requested to pick a subset containing any number of alternatives. In the context of subset voting we merge three choice paradigms, “approval voting“ from political science, the “weak utility model” from mathematical psychology, and “social welfare orderings” from social choice theory. We use a probabilistic choice model proposed by Falmagne and Regenwetter (1996) built upon the notion that each voter has a personal ranking of the alternatives and chooses a subset at the top of the ranking. Using an extension of Sen's (1966) theorem about value restriction, we provide necessary and sufficient conditions for this empirically testable choice model to yield a social welfare ordering. Furthermore, we develop a method to compute Borda scores and Condorcet winners from subset choice probabilities. The technique is illustrated on an election of the Mathematical Association of America (Brams, 1988). Received: 18 August 1995 / Accepted: 13 February 1997     

Generalized median social welfare functions

The article considers the construction of social welfare functions when the set of alternatives is the two-dimensional nonnegative orthant, as would be the case if there are two divisible public goods which can be consumed in any nonnegative quantities. With individual and social preferences required to be linear and strictly monotonic, but otherwise unrestricted, we characterize all of the social welfare functions which satisfy binary independence of irrelevant alternatives and anonymity and which satisfy binary independence of irrelevant alternatives, anonymity, and weak Pareto. These classes of social welfare functions are shown to be formally equivalent to the classes of social choice functions characterized by Moulin in his study of strategy-proof social choice with single-peaked preferences.We are grateful to Charles Blackorby, Hervé Moulin, and an anonymous referee for their comments.     

Top-Pair and Top-Triple Monotonicity

We say that a social choice function (SCF) satisfies Top-k Monotonicity if the following holds. Suppose the outcome of the SCF at a preference profile is one of the top k-ranked alternatives for voter i. Let the set of these k alternatives be denoted by B. Suppose that i’s preference ordering changes in such a way that the set of first k-ranked alternatives remains the set B. Then the outcome at the new profile must belong to B. This definition of monotonicity arises naturally from considerations of set “improvements” and is weaker than the axioms of strong positive association and Maskin Monotonicity. Our main results are that if there are two voters then a SCF satisfies unanimity and Top-2 or Top-pair Monotonicity if and only if it is dictatorial. If there are more than two voters, then Top-pair Monotonicity must be replaced by Top-3 Monotonicity (or Top-triple Monotonicity) for the analogous result. Our results demonstrate that connection between dictatorship and “improvement” axioms is stronger than that suggested by the Muller–Satterthwaite result (Muller and Satterthwaite in J Econ Theory 14:412–418, 1977) and the Gibbard–Sattherthwaite theorem.     

Identification of domain restrictions over which acyclic, continuous-valued, and positive responsive social choice rules operate

We consider a social choice problem in various economic environments consisting of n individuals, 4≤n<+∞, each of which is supposed to have classical preferences. A social choice rule is a function associating with each profile of individual preferences a social preference that is assumed to be complete, continuous and acyclic over the alternatives set. The class of social choice rules we deal with is supposed to satisfy the two conditions; binary independence and positive responsiveness. A new domain restriction for the social choice rules is proposed and called the classical domain that is weaker than the free triple domain and holds for almost all economic environments such as economies with private and/or public goods. In this paper we explore what type of classical domain that admits at least one social choice rule satisfying the mentioned conditions to well operate over the domain. The results we obtained are very negative: For any classical domain admitting at least one social choice rule to well operate, the domain consists only of just one profile.     

Nash implementable domains for the Borda count

We characterize the preference domains on which the Borda count satisfies Maskin monotonicity. The basic concept is the notion of a “cyclic permutation domain” which arises by fixing one particular ordering of alternatives and including all its cyclic permutations. The cyclic permutation domains are exactly the maximal domains on which the Borda count is strategy-proof when combined with every possible tie breaking rule. It turns out that the Borda count is monotonic on a larger class of domains. We show that the maximal domains on which the Borda count satisfies Maskin monotonicity are the “cyclically nested permutation domains” which are obtained from the cyclic permutation domains in an appropriately specified recursive way. We thank József Mala for posing the question of Nash implementability on restricted domains that led to this research. We are very grateful to two anonymous referees and an associate editor for their helpful comments and suggestions. The second author gratefully acknowledges financial support from the Hungarian Academy of Sciences (MTA) through the Bolyai János research fellowship.     

A note on contestation-based tournament solutions

In tournaments, one alternative contests another if is a “winner” among only alternatives that beat it. This paper examines the consequences and limitations of the contestation relation by considering a procedure in which alternatives that are contested are iteratively eliminated from consideration. In doing so, a new family of tournament solutions are introduced and related to existing refinements of the Banks set. Findings show that iterated removal of contested alternatives a limited device for choosing from tournaments. These results contrast with results regarding the top-set of the contestation relation. Results highlight the role of the top-set operator for choice from tournaments.     

Working mothers’ decisions on childcare: the case of Spain

This paper aims to analyze household decisions regarding the childcare of young children. We present two specifications. The first one assumes a sequential decision process. Firstly, parents choose between paid or unpaid care and, secondly, those who opt for paid childcare must decide whether to take their children to a nursery or pre-school or employ somebody to care for them. The second specification is a multinomial Logit in which it is assumed that parents choose from three alternatives: unpaid care, paid care by a nanny, and center-based care. We apply our models to a sample of working mothers with children under three. The database used is the 2008–2010 Spanish Survey of Quality of Working Life (Encuesta de Calidad de Vida en el Trabajo). The results are in line with previous work: Parental education, family composition, income and the characteristics of the mother’s job are important factors in determining the type of childcare chosen for under-three-year-olds.     

Who Protests in America: An Analysis of Three Political Alternatives—Inaction,Institutionalized Politics,or Protest

Theories of social movements and collective action typically present social protest as one of three alternatives available to the individual: inaction, institutionalized political action, or protest. These political alternatives are rarely considered simultaneously nor are they modeled explicitly. In this paper we make use of survey data from a representative sample of the United States population. We employ multinomial logistic regression to determine what differentiates those who protest from those who engage only in institutionalized politics and from those who engage in no political action. We find that those who engage in social protest are similar in many respects to those who engage actively in institutionalized politics, yet education on social and political issues, participation in community organizations, and frequent church attendance increases the likelihood that individuals will engage in protest relative to institutionalized politics.     

The measurement of opportunity inequality: a cardinality-based approach

We consider the problem of ranking distributions of opportunity sets on the basis of equality. First, conditional on a given ranking of individual opportunity sets, we define the notion of an equalizing transformation. Then, assuming that the opportunity sets are ranked according to the cardinality ordering, we formulate the analogues of the notions of the Lorenz partial ordering, equalizing (Dalton) transfers, and inequality averse social welfare functions – concepts which play a central role in the literature on income inequality. Our main result is a cardinality-based analogue of the fundamental theorem of inequality measurement: one distribution Lorenz dominates another if and only if the former can be obtained from the latter by a finite sequence of rank preserving equalizations, and if and only if the former is ranked higher than the latter by all inequality averse social welfare functions. In addition, we characterize the smallest monotonic and transitive extension of our cardinality-based Lorenz inequality ordering. Received: 2 May 1995 / Accepted: 11 October 1996     

Hansson’s theorem for generalized social welfare functions: an extension

 Hansson (1969) sets forth four conditions satisfied by no generalized social welfare function (GSWF), a mapping from profiles of individual preferences to arbitrary social preference relations. Though transitivity is not imposed on social preferences, one of Hansson’s conditions requires that socially maximal alternatives always exist. Of course, this condition is not satisfied by the majority GSWF. We prove a generalization of Hansson’s theorem that requires the existence of maximal alternatives only in very special cases. Our result applies to the majority GSWF and a large class of other GSWFs that sometimes produce no maximal alternatives. Received: 10 July 1995/Accepted: 4 March 1996     

Inefficient committees: small elections with three alternatives

We consider small committees which have to elect one of three alternatives using the simple plurality rule. Committee members have common, state-dependent preferences and receive imprecise private signals about the state of nature prior to the election. We are interested in whether the committee decision is efficient, that is whether the probability with which the committee elects the correct alternative is higher than the probability with which one single individual alone—on behalf of the others—would. It has been shown that there exists a unique efficient equilibrium in elections with two alternatives. We show that this result does not extend to elections with more alternatives. Multiple equilibria may exist for the same committee, and there may be both efficient and inefficient ones. Informative voting may or may not be an equilibrium. Also contrary to two-alternative elections, there exist responsive equilibria in which voters vote ‘against’ their signal. As a consequence, only two alternatives receive positive expected vote shares and the outcome is inefficient.     

On thoughtfulness and generosity in sequential decisions

In this article, we develop frameworks to study the notions of thoughtfulness and generosity in sequential choice situations involving two individuals. In such situations, by taking particular actions, an individual (the first mover) can induce various sets of alternatives to be available for the other individual (the second mover) to choose from. We view those sets of alternatives as opportunity sets reflecting degrees of thoughtfulness or generosity exhibited by the first mover toward the second mover. We axiomatically study several specific rules for ranking opportunity sets in terms of either thoughtfulness or generosity.     

Utility and the individual: An analysis of internal conflicts

Herbert Simon has argued that economic agents do not maximise a transitive ordering but rather adopt what he calls satisficing behaviour. He argues that such behaviour is rational. This paper aims to provide a theory to support Simon's viewpoint. Because of social choice problems an individual with multiple objectives may find it impossible to construct a transitive ordering and hence may have to adopt satisficing type behaviour. We show that whether or not an individual adopts satisficing behaviour depends on the information available.I would like to thank Amartya Sen, the members of a seminar in Oxford, and an anonymous referee for their comments on previous drafts of this paper.