Ranking opportunity sets on the basis of their freedom of choice and their ability to satisfy preferences: A difficulty

This paper examines a possibility of enlarging the domain of definition of individual preferences suggested by the recent literature on freedom of choice. More specifically, the possibility for an individual to have preferences that depend upon both the opportunity set that she faces and the particular alternative that she chooses from that set is considered. Even more specifically, the possibility for these preferences to value freedom of choice, as defined by the set theoretic relation of inclusion, while being consistent, in a certain sense, with the existence of a preference ordering over the options contained in opportunity sets is investigated. It is shown in the paper that a necessary condition for the existence of any transitive extended preferences of this type is for freedom of choice to be given no intrinsic importance. Received: 22 November 1995 / Accepted: 11 January 1997     

A systematic approach to the construction of non-empty choice sets

Suppose a strict preference relation fails to possess maximal elements, so that a choice is not clearly defined. I propose to delete particular instances of strict preferences until the resulting relation satisfies one of a number of known regularity properties (transitivity, acyclicity, or negative transitivity), and to unify the choices generated by different orders of deletion. Removal of strict preferences until the subrelation is transitive yields a new solution with close connections to the “uncovered set” from the political science literature and the literature on tournaments. Weakening transitivity to acyclicity yields a new solution nested between the strong and weak top cycle sets. When the original preference relation admits no indifferences, this solution coincides with the familiar top cycle set. The set of alternatives generated by the restriction of negative transitivity is equivalent to the weak top cycle set.     

The direct social preference relation in the theory of public expenditure

It is shown that if there is a finite number of private goods, a single public good, and the individual preferences satisfy certain monotonicity and separability conditions then there is a unique and complete social preference relation defined on the set of allocations by the requirement that the relation is individualistic in terms of the individual ordinal preferences. This relation, called the direct social preference relation, is derived without imposing interpersonal welfare comparisons and all its ordinal properties are inherited directly from those of the individual preferences. However, an allocation which is maximal in terms of the direct social preference relation on the set of feasible allocations is in general not Pareto optimal and the relation may therefore not be suitable as a guide to optimizing social choice.This version of the paper has benefitted from J. Weymark's insightful and detailed comments. In addition, valuable suggestions have been received from G. C. Archibald, C. Blackorby, D. Donaldson and D. Primont. All remaining errors are the sole responsibility of the author     

Essential alternatives and freedom rankings

We study the problem of ranking opportunity sets in terms of freedom of choice. The analysis is based on the notion of essential alternatives introduced in Puppe (J Econ Theory 68:174–199, 1996). An alternative in an opportunity set is called essential if by deleting it, the reduced opportunity set offers less freedom than the original set. We provide an axiomatic characterization of the ranking according to which an opportunity set offers more freedom than another opportunity set if its share of essential elements in their union is larger.     

Freedom of choice in a social context: comparing game forms

In this paper, the set of outcomes of game forms is introduced as the relevant attribute for evaluating freedom of choice. These sets are defined as the cartesian product of every individual’s set of available options. It is argued that doing so is one way of taking into account social interactions when evaluating individual freedom. A set of axioms is introduced, each of which conveys some intuitions about how interactions affect freedom of choice, axioms by the mean of which two criteria, the Max and the MaxMin, are characterised for comparing game forms in terms of the freedom of choice they offer. These criteria are based, respectively, on the comparison of the best and the worst outcome the individual can reach in the game form.     

Freedom of choice and expected compromise

This article develops a new measure of freedom of choice based on the proposal that a set offers more freedom of choice than another if, and only if, the expected degree of dissimilarity between a random alternative from the set of possible alternatives and the most similar offered alternative in the set is smaller. Furthermore, a version of this measure is developed, which is able to take into account the values of the possible options.     

Flexibility of choice versus reduction of ambiguity

This paper explores the problem of a social planner willing to improve the welfare of individuals who are unable to compare all available alternatives. The optimal decision trades off the individuals’ desire for flexibility versus their aversion towards ambiguous choice situations. We introduce an axiom system that formalizes this idea. Our main result characterizes the preference maximizing opportunity set. It is a maximal set that consists of mutually comparable alternatives. It also has the property that it maximizes the sum of the distances between its ordered elements for some appropriate pseudometric imposed on the set of possible choices.     

Welfare, freedom of choice and composite utility in the logit model

Discrete choice models characterize the alternatives in the choice set by utilities/attributes. The decision making is described by a probability distribution over the choice set. In this paper we introduce a welfare measure based on expected payoff and expected freedom of choice for the simple one parameter logit model. In this case the welfare measure turns out to be the so called composite utility. This means that the composite utility can be interpreted as the combined benefit of expected payoff and expected freedom of choice. The proposed welfare measure can be extended to the linear-in-parameters logit model and nested logit models and others. The proposed welfare measure is formulated in terms of the choice probability distribution. It depends on the form of the probabilities, but not on any particular derivation of the distribution.     

Justifiable preferences over opportunity sets

In this paper we say that a preference over opportunity sets is justifiable if there exists a reflexive and complete binary relation on the set of alternatives, such that one opportunity set is at least as good as a second, if and only if the there is at least one alternative from the first set which is no worse than any alternative of the two sets combined together, with respect to the binary relation on the alternatives. In keeping with the revered tradition set by von Neumann and Morgenstern we call a reflexive and complete binary relation, an abstract game (note: strictly speaking von Neumann and Morgenstern refer to the asymmetric part of a reflexive and complete binary relation as an abstract game; hence our terminology though analytically equivalent, leads to a harmless corruption of the original meaning). In this paper we obtain a necessary and sufficient condition for the justifiability of transitive and quasi transitive preferences over opportunity sets. I would like to thank Prasanta Pattanaik for motivation in this research. I would also like to thank Maurice Salles and an anonymous referee of this journal for useful suggestions leading to considerable improvement in the presentation. An earlier version of this paper was presented at the Sixth Annual Conference on Econometric Modeling for Africa, held at Pretoria from July 4–6, 2001. I would like to thank all the conference participants for their observations on my paper. However, the sole responsibility for errors that do remain is my own.     

More on preference and freedom

The paper seeks to formalize the notion of effective freedom or the freedom to realize meaningful choices. The definition of meaningful choice used in this paper is based on the preference orderings that a reasonable person may have. I argue that only alternatives that can be selected by a reasonable person from the set of all possible alternatives provide a meaningful choice. I discuss this approach and provide an axiomatization of the cardinality rule and two lexicographic versions of this rule in this context. Received: 24 September 1996/Accepted: 26 January 2000     

Libertarian collective decision-making: A new framework

A model of collective decision-making is presented which enables us to analyze the allocation of individual rights and liberties. The model broadens the traditional social choice framework. In social choice theory it is usually assumed that individuals have preferences over a set of feasible alternatives and that society reaches a decision on the basis of those preferences only. In the model presented in this paper, decision procedures do not only take information about individual preferences as input, but also information about individual freedom. The specific decision procedures we present and analyze can be characterized as libertarian.This paper was written while I was a visitor at the University of California, Riverside. The visit was made possible by financial support of the Netherlands Organization of Scientific Research (NWO). I am extremely grateful to Prasanta Pattanaik for many stimulating discussions on the subject. For helpful comments I also thank Ad van Deemen, Grahame Lock, Huib Pellikaan and Marcel Wissenburg. Finally, I express my thanks to Wulf Gaertner and two anonymous referees.     

Coalitionally strategy-proof social choice correspondences and the Pareto rule

This paper studies coalitional strategy-proofness of social choice correspondences that map preference profiles into sets of alternatives. In particular, we focus on the Pareto rule, which associates the set of Pareto optimal alternatives with each preference profile, and examine whether or not there is a necessary connection between coalitional strategy-proofness and Pareto optimality. The definition of coalitional strategy-proofness is given on the basis of a max–min criterion. We show that the Pareto rule is coalitionally strategy-proof in this sense. Moreover, we prove that given an arbitrary social choice correspondence satisfying the coalitional strategy-proofness and nonimposition, all alternatives selected by the correspondence are Pareto optimal. These two results imply that the Pareto rule is the maximal correspondence in the class of coalitionally strategy-proof and nonimposed social choice correspondences.     

Axiomatic foundations for fairness-motivated preferences

Much work in social choice theory takes individual preferences as uninvestigated inputs into aggregation functions designed to reflect considerations of fairness. Advances in experimental and behavioural economics show that fairness can also be an important motivation in the preferences of individuals themselves. A proper characterisation of how fairness concerns enter such preferences can enrich the informational basis of many social choice exercises. This paper proposes axiomatic foundations for individual fairness-motivated preferences that cover most of the models developed to rationalise observed behaviour in experiments. These models fall into two classes: Outcome-based models, which see preferences as defined only over distributive outcomes, and context-dependent models, which allow rankings over distributive outcomes to change systematically with non-outcome factors. I accommodate outcome-based and context-sensitive fairness concerns by modelling fairness-motivated preferences as a reference-dependent preference structure. I first present a set of axioms and two theorems that generate commonly used outcome-based models as special cases. I then generalise the axiomatic basis to allow for reference-dependence, and derive a simple functional form in which the weight on each person’s payoff depends on a reference vector of how much each person deserves.     

Arrow��s theorem and max-star transitivity

In the literature on social choice with fuzzy preferences, a central question is how to represent the transitivity of a fuzzy binary relation. Arguably the most general way of doing this is to assume a form of transitivity called max-star transitivity. The star operator in this formulation is commonly taken to be a triangular norm. The familiar max- min transitivity condition is a member of this family, but there are infinitely many others. Restricting attention to fuzzy aggregation rules that satisfy counterparts of unanimity and independence of irrelevant alternatives, we characterise the set of triangular norms that permit preference aggregation to be non-dictatorial. This set contains all and only those norms that contain a zero divisor.     

The possibility of group choice: pairwise comparisons and merging functions

Preferences in Arrow’s conditions are ordinal. Here we show that when intensity of preference represented by reciprocal pairwise comparisons is considered, it is always possible to construct an Arrowian social welfare function using a two-stage social choice process. In stage 1, the individual pairwise relations are mapped into a social pairwise relation. In stage 2, the social pairwise relation is used to generate a cardinal ranking and this ranking is then used to select a particular member of the choice set.     

Combining preference ordering and contingent valuation methods to assess non market benefit of alternative afforestation projects

The application of the contingent valuation method (CVM) in this paper incorporates a prior preference ordering of several alternative future afforestation programmes which could be implemented in Ireland over the next decade. This particular experimental design is thereby shown to reveal the potentially conflicting preferences of different groups within society. These findings are used to devise appropriate CVM scenarios to take account, not only of the efficiency gains of choosing a single policy alternative over others, but also the effects on the distribution of non market benefit between different groups within society, arising from choice between alternatives.     

Strategic behaviour and a notion of ex ante efficiency in a voting model

A person is said to prefer in the stochastic dominance sense one lottery-over-outcomes over another lottery-over-outcomes if the probability of his (at least) first choice being selected in the first lottery is greater than or equal to the analogous probability in the second lottery, the probability of his at least second choice being selected in the first lottery is greater than or equal to the analogous probability in the second lottery, and so on, with at least one strict inequality. This (partial) preference relation is used to define straightforwardness of a social choice function that maps profiles of ordinal preferences into lotteries over outcomes. Given a prior probability distribution on profiles this partial preference ordering (taking into account the additional randomness) is used to induce a partial preference ordering over social choice functions for each individual. These are used in turn to define ex ante Pareto undominated (efficient) social choice functions. The main result is that it is impossible for a social choice function to be both ex ante efficient and straightforward. We also extend the result to cardinal preferences and expected utility evaluations.This work was supported by Grant #SOC 77-27403 and #SES 80-26086 from the National Science Foundation. It has been prepared at the University of Illinois and the University of Pennsylvania. We want to thank Steve Matthews and an anonymous referee for helpful comments     

Free triples,large indifference classes and the majority rule

We study classes of voting situations where agents may exhibit a systematic inability to distinguish between the elements of certain sets of alternatives. These sets of alternatives may differ from voter to voter, thus resulting in personalized families of preferences. We study the properties of the majority relation when defined on restricted domains that are the cartesian product of preference families, each one reflecting the corresponding agent’s objective indifferences, and otherwise allowing for all possible (strict) preference relations among alternatives. We present necessary and sufficient conditions on the preference domains of this type, guaranteeing that majority rule is quasi-transitive and thus the existence of Condorcet winners at any profile in the domain, and for any finite subset of alternatives. Finally, we compare our proposed restrictions with others in the literature, to conclude that they are independent of any previously discussed domain restriction.     

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     

Path independent choice and the ranking of opportunity sets

The indirect utility principle provides an instrumentalist basis for ranking opportunity sets, given an underlying preference ranking on alternatives. Opportunity set A is weakly preferred to B if A includes at least one preference-maximising element from $A\cup B$ . We introduce the Plott consistency principle as a natural extension of this logic to decision-makers who choose amongst alternatives according to a path independent choice function. Such choice functions need not be rationalisable by a preference order. Plott consistency requires that A is an acceptable choice from $\left\{ A, B\right\} $ if A includes at least one element from the set of acceptable choices from $A\cup B$ . We explore necessary and sufficient conditions (imposed on a choice function defined on collections of opportunity sets) for Plott consistency.