Our aim in this chapter is to draw lessons from current theory on the evolution of human cooperation for the management of contemporary commons. Evolutionary theorists have long been interested in cooperation but social scientists have documented patterns of cooperation in humans that present unusual problems for conventional evolutionary theory (and for rational choice explanations as well). Humans often cooperate with nonrelatives and are prone to cooperate in one-shot games. Cooperation is quite dependent on social institutions. We believe that this (...) last fact is the critical clue to understanding human cooperation. Models of cultural evolution suggest that group selection is a more potent force on culture than on genes. Evolutionary theory is in essence a theory of preferences in terms of rational actor theory and is thus complementary to the bounded rational choice models that underpin so much theorizing in the social sciences. Thus, the theory suggests a source for prosocial impulses, and leads to predictions about the limits of human altruism and constraints likely to be imposed upon the evolution of social institutions. We also consider the dynamics of genes as they coevolved with increasingly sophisticated cultural institutions over the long course of human evolution in the Pleistocene. We hypothesize that the long exposure of human populations to group selected cultural norms and preferences is likely to have resulted in an innate psychology adapted to living in egalitarian, cooperative societies of a few hundred to a few thousand people. We call this the tribal social instincts hypothesis. The evolution of complex societies in the past few thousand years constitutes a series of natural experiments that test this hypothesis. If it is correct, the institutions of complex societies must somehow take advantage of the prosocial elements of the tribal instincts while finessing the problem that the tribal social instincts are ill adapted to life in large, hierarchical, inegalitarian societies with extensive dominance of subordinates by elites.. (shrink)

We consider two no-show paradoxes, in which a voter obtains a preferable outcome by abstaining from a vote. One arises when the casting of a ballot that ranks a candidate in first place causes that candidate to lose the election, superseded by a lower-ranked candidate. The other arises when a ballot that ranks a candidate in last place causes that candidate to win, superseding a higher-ranked candidate. We show that when there are at least four candidates and when voters may (...) express indifference, every voting rule satisfying Condorcet’s principle must generate both of these paradoxes. (shrink)

This paper examines social choice theory with the strong Pareto principle. The notion of conditional decisiveness is introduced to clarify the underlying power structure behind strongly Paretian aggregation rules satisfying binary independence. We discuss the various degrees of social rationality: transitivity, semi-transitivity, the interval-order property, quasi-transitivity, and acyclicity.

The purpose of this article is to introduce a Cartesian product structure into the social choice theoretical framework and to examine if new possibility results to Gibbard’s and Sen’s paradoxes can be developed thanks to it. We believe that a Cartesian product structure is a pertinent way to describe individual rights in the social choice theory since it discriminates the personal features comprised in each social state. First we define some conceptual and formal tools related to the Cartesian product structure. (...) We then apply these notions to Gibbard’s paradox and to Sen’s impossibility of a Paretian liberal. Finally we compare the advantages of our approach to other solutions proposed in the literature for both impossibility theorems. (shrink)

This paper provides a computational characterization of coherence that applies to a wide range of philosophical problems and psychological phenomena. Maximizing coherence is a matter of maximizing satisfaction of a set of positive and negative constraints. After comparing five algorithms for maximizing coherence, we show how our characterization of coherence overcomes traditional philosophical objections about circularity and truth.

Arrow's Independence of Irrelevant Alternatives Condition is examined. It is shown why the standard rationale for (or against) the condition tends to be inconclusive as it fails to consider the basic ‘game’ issue in social choice. Specifically it is explained how some recent results (Gibbard-Satterthwaite) on the general non-existence of strategy-proof voting procedures provide the strongest rationale for the independence condition. Also, it is shown that this rationale was exactly the one used by Condorcet in his work on decision rules (...) for juries and elections. (shrink)

Since its founding in 1863, the National Academy of Sciences (NAS) has occupied a special niche in the complex ecology of advice-giving in the United States. Established as a small, private organization with special responsibilities and obligations vis à vis the American people and government, the Academy has expanded considerably in the past century and a half and now releases, through the National Research Council (NRC), its operating arm, more than 200 reports per year, on topics covering nearly the entire (...) range of science, engineering, health, and education. The development of the organization, its basic ethos, and its evolving structures and processes can be seen as examples of what Herbert Simon called procedural rationality : the pursuit of reasonably good solutions to complex problems based on appropriate deliberation. (shrink)

This paper discusses justice-constrained libertarian claims that were proposed as a way to circumvent the impossibility of the Paretian liberal. Since most of the results are negative in character, we suggest an alternative route: A requirement on the structure of individual orderings should be combined with the idea that under particular circumstances individual decisiveness should be controlled by higher-order principles.

The usual procedure in the theory of social choice consists in postulating some desirable properties which an aggregation procedure should verify and derive from them the features of a corresponding social choice function and the outcomes that arise at each possible profile of preferences. In this paper we invert this line of reasoning and try to infer, up from what we call social situations the criteria verified in the implicit aggregation procedure. This inference process, which extracts intensional from extensional information (...) can be seen as an exercise in “qualitative statistics”. (shrink)

A phenomenon called perspectival disagreement is laid out and modelled on the basis of modifications to known consensus measures for qualitative representations of preferences and transitive values by binary relations. Cases of perspectival disagreement are of general philosophical interest, because they allow for the possibility that two or more agents judge the value positions of other agents differently even when their assessments are based on the same evidence. Various examples of perspectival disagreement are given, generalizations are discussed, and it is (...) argued that any representation by cardinal utilities also gives rise to some form of perspectivity. Although the examples strongly suggest that this phenomenon occurs in real life, it is concluded in the end that it does not pose any fundamental threat to representations of preferences and values as binary relations. Instead, position‐sensitive measures of disagreement ought to be taken as a modelling option for cases in which the relative importance of preference changes matters to an agent. (shrink)

It is commonplace to suppose that the theory of individual rational choice is considerably less problematic than the theory of collective rational choice. In particular, it is often assumed by philosophers, economists, and other social scientists that an individual's choices among outcomes accurately reflect that individual's underlying preferences or values. Further, it is now well known that if an individual's choices among outcomes satisfy certain plausible axioms of rationality or consistency, that individual's choice-behavior can be interpreted as maximizing expected utility (...) on a utility scale that is unique up to a linear transformation. Hence, there is, in principle, an empirically respectable method of measuring individuals' values and a single unified schema for explaining their actions as value maximizing. (shrink)

This paper defends two related claims about belief. First, the claim that unlike numerical degrees of belief, comparative beliefs are primitive and psychologically real. Second, the claim that the fundamental norm of Probabilism is not that numerical degrees of belief should satisfy the probability axioms, but rather that comparative beliefs should satisfy certain constraints.

We can formalize judgments as logical formulas. Judgment aggregation deals with judgments of several agents, which need to be aggregated to a collective judgment. There are several logical formalizations of judgment aggregation. This paper focuses on a modal formalization which nicely expresses classical properties of judgment aggregation rules and famous results of social choice theory, like Arrow’s impossibility theorem. A natural deduction system for modal logic of judgment aggregation is presented in this paper. The system is sound and complete. As (...) an example of derivation, a formal proof of Arrow’s impossibility theorem is given. (shrink)

The 1985 paper by Carlos Alchourrón, Peter Gärdenfors, and David Makinson, “On the Logic of Theory Change: Partial Meet Contraction and Revision Functions” was the starting-point of a large and rapidly growing literature that employs formal models in the investigation of changes in belief states and databases. In this review, the first twenty-five years of this development are summarized. The topics covered include equivalent characterizations of AGM operations, extended representations of the belief states, change operators not included in the original (...) framework, iterated change, applications of the model, its connections with other formal frameworks, computatibility of AGM operations, and criticism of the model. (shrink)

This paper provides an introductory review of the theory of judgment aggregation. It introduces the paradoxes of majority voting that originally motivated the field, explains several key results on the impossibility of propositionwise judgment aggregation, presents a pedagogical proof of one of those results, discusses escape routes from the impossibility and relates judgment aggregation to some other salient aggregation problems, such as preference aggregation, abstract aggregation and probability aggregation. The present illustrative rather than exhaustive review is intended to give readers (...) new to the field of judgment aggregation a sense of this rapidly growing research area. (shrink)

This paper provides an introductory review of the theory of judgment aggregation. It introduces the paradoxes of majority voting that originally motivated the field, explains several key results on the impossibility of propositionwise judgment aggregation, presents a pedagogical proof of one of those results, discusses escape routes from the impossibility and relates judgment aggregation to some other salient aggregation problems, such as preference aggregation, abstract aggregation and probability aggregation. The present illustrative rather than exhaustive review is intended to give readers (...) new to the field of judgment aggregation a sense of this rapidly growing research area. (shrink)

This article investigates the relationship among the weak Pareto principle, the strong Pareto principle, and positive responsiveness in the context of voting. First, it is shown that under a mild domain condition, if an anonymous and neutral collective choice rule (CCR) is complete and transitive, then the weak Pareto principle and the strong Pareto principle are equivalent. Next, it is shown that under another mild domain condition, if a neutral CCR is transitive, then the strong Pareto principle and positive responsiveness (...) are equivalent. By applying these results, we obtain a new characterization of the method of majority decision. (shrink)

This paper studies the welfare consequences of strategic voting in two commonly used parliamentary agendas by comparing the average utilities obtained in simulated voting under two behavioural assumptions: expected utility maximising behaviour and sincere behaviour. The average utility obtained in simulations is higher with expected utility maximising behaviour than with sincere voting behaviour under a broad range of assumptions. Strategic voting increases welfare particularly if the distribution of preference intensities correlates with voter types.

In recent years, judgement aggregation has emerged as an important area of social choice theory. Judgement aggregation is concerned with aggregating sets of individual judgements over logically connected propositions into a set of collective judgements. It has been shown that even seemingly weak conditions on the aggregation function make it impossible to find functions that produce rational collective judgements from all possible rational individual judgements. This implies that the step from individual judgements to collective judgements requires trade-offs between different desiderata, (...) such as universal domain, rationality, epistemological quality, and unbiasedness. These dilemmas challenge us to decide which conditions we should relax. The typical application for judgement aggregation is the problem of group decision making. Juries and expert committees are the stock examples. However, the relevance of judgement aggregation goes beyond these cases. In this survey I review some core results in the field of judgement aggregation and social epistemology and discuss their implications for the analysis of distributed thinking. (shrink)

The Problem Economic efficiency is naturally thought to be a virtue of social policies and decisions, and cost-benefit analysis is commonly regarded as a technique for measuring economic efficiency. It is not surprising, then, that CB analysis is so widely used in social policy analysis. However, there is a great deal of controversy about CB analysis, including controversy about its underlying philosophical rationale. The rationales that have been proposed fall into three basic, though not mutually exclusive categories. There are moralist (...) views to the effect that an acceptable CB analysis would provide, or contribute to, an ethical appraisal of proposed policies or projects. There are rationalist views to the effect that an acceptable CB analysis would contribute to the selection of social policies and projects that are “socially rational.” Finally, there are so-called management science views to the effect that the purpose of CB analysis is to promote the achievement of objectives held by the policy maker, whatever they may be. Different positions are available within each of these categories. But there is also the possibility that CB analysis lacks any viable rationale. I will examine some of the major rationales for CB analysis in this paper, and I will suggest that the last view is close to the truth. (shrink)

It has often been recommended that the differing probability distributions of a group of experts should be reconciled in such a way as to preserve each instance of independence common to all of their distributions. When probability pooling is subject to a universal domain condition, along with state-wise aggregation, there are severe limitations on implementing this recommendation. In particular, when the individuals are epistemic peers whose probability assessments are to be accorded equal weight, universal preservation of independence is, with a (...) few exceptions, impossible. Under more reasonable restrictions on pooling, however, there is a natural method of preserving the independence of any fixed finite family of countable partitions, and hence of any fixed finite family of discrete random variables. (shrink)

Arrow's Independence of Irrelevant Alternatives (IIA) has been under criticism for decades for not taking account of preference intensities. Computer-simulation results by Aki Lehtinen concerning strategic voting under various voting rules show that this intensity argument does not need to rest on mere intuition. Voters may express intensities by voting strategically, and that this has beneficial aggregate-level consequences: utilitarian efficiency is higher if voters engage in strategic behaviour than if they always vote sincerely. Strategic voting is thus unambiguously beneficial under (...) a utilitarian evaluation of outcomes. What has been considered the main argument for IIA turns out to be one against it. This paper assesses the implications of these results for interpretations of Arrow's theorem and the Gibbard-Satterthwaite theorem in a discussion on the methodological and philosophical arguments concerning preference intensities and IIA. (shrink)

In an article from 1973, Rittel and Webber distinguished between “tame” or “benign” problems on the one hand and “wicked” problems on the other. The authors argued that wicked problems occur in nearly all public policy issues. Since different groups adhere to different value-sets, solutions can only be expressed as better or worse. By no means can they be viewed as definitive or objective. In this paper we shall consider, from this very angle, the theory of social choice which is (...) about the aggregation of individual preferences with the aim to derive a consistent social preference. We shall show that collective choice offers wicked problems of various types which differ in their degree of severity. We shall hereby concentrate on welfare functions and voting schemes of different kinds and shall discuss these in the light of various criteria such as Arrow’s independence condition, Condorcet consistency, monotonicity, manipulability, and other properties. (shrink)

This paper provides a generalized characterization of the family of independence conditions which are equivalent to independence of irrelevant alternatives by proposing a pair-based refinement of S\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\mathcal {S}$$\end{document}-independence. Equipped with the new result, the relation between external independence conditions and independence of irrelevant alternatives is explored.

My dissertation titled Two Models of Consensus is based on five arguments. 1. Consensus is asymmetrical. 2. Consensus is partial or limited unanimity. 3. Consensus and democracy do have a concomitant relation. 4. Consensus is not organic to political systems. 5. Consensus depends upon civil society, subsidiarity, and the dominant cultural paradigm of society. In the first chapter titled "Historical Specificity of the Western Conception of Civil Society" I argue that concept of civil society evolved under certain conditions in a (...) liberal democratic tradition such as shared social imaginaries. As an example of how diversity could lead to hypostatization of cultural differences, I exposit the concept of Indian caste system. In the second chapter, "Intersubjectivity and the Problem of Cultural Identities", I compare the ideas of Hans Georg Gadamer and George Herbert Mead about self- interested action and mutual cooperative action. Gadamer and Mead emphasize intersubjective communication, I Thou relationships. I explain the importance of the I Thou relationship for a consensual activity. The third chapter, "Consensus in the Realm of Science", discusses the impact of science as the context of justification in advanced liberal democracies and its effect on consensus. Charles Sanders Peirces attempt to apply his scientific method to arrive at a consensus in the social sphere is also discussed in this chapter. In the fourth chapter, "Kwasi Wiredu The Akan Conception of Communitarian Consensus", I discuss Kwasi Wiredus emphasis on achieving a consensus on the basis of what is and not what ought to be, in the social realm. Wiredu differentiates between a government by consent and a government by consensus. I elaborate Wiredu's abakysis of the process of consensus that was in vogue in the Akan community of Ghana. In the final chapter, "Political Consensus - Intra-cultural and Extra-cultural," I argue that consensus is asymmetrical. It is imperative to compromise in social, political, economic, and religious beliefs on the basis of weak deontological and weak consequential approaches. Consensus necessitates a synthesis of different kinds of social actions such as purposive-instrumental, traditional, value-laden, and communicative action into what I call the Cooperative Action. Only such an action can speak across cultures and facilitate genuine cross-cultural interaction. (shrink)

Separates the purely combinatorial component of Arrow's impossibility theorem in the theory of collective preference from its decision-theoretic part, and likewise for the closely related Blair/Bordes/Kelly/Suzumura theorem. Such a separation provides a particularly elegant proof of Arrow's result, via a new 'splitting theorem'.

Judgment aggregation studies how collective opinions arise from the aggregation of individual ones. This article surveys a variety of aggregation rules (possible ways of aggregating individual judgments into collective ones). Aggregation by majority opinion is known to satisfy some but not all the desiderata for an aggregation rule. More general impossibility results show that not all the natural desiderata can be satisfied by a single aggregation rule. To interpret these results, we focus here on some applications of judgment aggregation models (...) in Epistemology. In particular, we explore their possible role in an account of collective belief and collective reason. The focus on these applications allows us to give precise answers concerning which of the natural desiderata must be abandoned. (shrink)

La théorie du choix social qui s'est développée durant les dernières décennies, notamment dans la ligne des travaux d'Arrow et de Sen , ne s'est pas seulement soldée par une série de résultats négatifs exprimés dans les théorèmes d'impossibilité d'Arrow, de Sen et d'autres; ses notions centrales ont aussi été utilisées de manière fort variée au point que cette théorie souffre aujourd'hui d'un déficit important qui se traduit par de multiples indéterminations conceptuelles.