We show that, when the number of participating agents n tends to infinity, all classical social choice rules are asymptotically strategy -proof with the proportion of manipulable profiles being of order O.

The purpose of this paper is to investigate the relationship between collective rationality and permissible collective choice rules using a unified approach inspired by Bossert and Suzumura (J Econ Theory 138:311–320, 2008). We consider collective choice rules satisfying four axioms: unrestricted domain, strong Pareto, anonymity, and neutrality. A number of new classes of collective choice rules as well as the Pareto and Pareto extension rules are characterized under various concepts of collective rationality: acyclicity, transitivity, quasi-transitivity, semi-transitivity, and (...) the interval order property. Further, new concepts of collective rationality, K-term acyclicity and K-term consistency, are proposed and the corresponding characterizations are provided. (shrink)

In many voting systems, voters’ preferences on a set of candidates are represented by linear orderings. In this context, scoring rules are well-known procedures to aggregate the preferences of the voters. Under these rules, each candidate obtains a fixed number of points, sk\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$s_k$$\end{document}, each time he/she is ranked k\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$k$$\end{document}th by one voter and the candidates are ordered according to the total number of (...) points they receive. In order to identify the best scoring rule to use in each situation, we need to know which properties are met by each of these procedures. Although some properties have been analyzed extensively, there are other properties that have not been studied for all scoring rules. In this paper, we consider two desirable social choice properties, the Pareto-optimality and the immunity to the absolute loser paradox, and establish characterizations of the scoring rules that satisfy each of these specific axioms. Moreover, we also provide a proof of a result given by Saari and Barney, where the scoring rules meeting reversal symmetry are characterized. From the results of characterization, we establish some relationships among these properties. Finally, we give a characterization of the scoring rules satisfying the three properties. (shrink)

This article provides a systematic analysis of social choice theory without the Pareto principle, by revisiting the method of Murakami Yasusuke. This article consists of two parts. The first part investigates the relationship between rationality of social preference and the axioms that make a collective choice rule either Paretian or anti-Paretian. In the second part, the results in the first part are applied to obtain impossibility results under various rationality requirements of social preference, such (...) as S-consistency, quasi-transitivity, semi-transitivity, the interval-order property, and acyclicity. (shrink)

Sometimes citizens disagree about political matters, but a decision must be made. We have two theoretical frameworks for resolving political disagreement. The first is the framework of social choice. In it, our goal is to treat parties to the dispute fairly, and there is no sense in which some are right and the others wrong. The second framework is that of collective decision-making. Here, we do believe that preferences are truth apt, and our moral consideration is owed not (...) to those who disagree but to the community that stands to benefit or suffer from the decision. In this chapter, I describe and explore these two frameworks. I conclude two things. First, analysis of real-world disagreement suggests that collective decision-making is the right way to model politics. In most, possibly even all, political disagreement, all parties believe (if implicitly) that there is an objective standard of correctness. Second, this matter is connected to the concept of pluralism. If pluralism is true, then collective decision-making cannot be applied to some political disagreements. More surprisingly, pluralism may rule out the applicability of social choice theory as well. (shrink)

A new property of collective choice rules that we refer to as superset robustness is introduced, and we employ it in several characterization results. The axiom requires that if all individual preference orderings expand weakly (in the sense of set inclusion), then the corresponding social preference relation must also expand weakly. In other words, if a given profile is changed by adding instances of weak preference to some individual relations, then the social weak preference relation for the (...) expanded profile must contain the social weak preference relation for the original—that is, the social relation cannot contract in response to the addition of pairs to the individual relations. We begin by examining social welfare functions (that is, collective choice rules such that the resulting social preferences are orderings) and then move on to rules that generate transitive (but not necessarily complete) social rankings. The remaining results of the paper focus on Suzumura-consistent collective choice rules. In all of these cases, it turns out that the property of superset robustness is closely related to classes of agreement-based collective choice rules. These are rules such that the social relation is determined by collecting the pairs on whose relative rankings the members of the decisive sets agree. (shrink)

In democracies citizens are supposed to have some control over the general direction of policy. According to a pretheoretical interpretation of this idea, the people have control if elections and other democratic institutions compel officials to do what the people want, or what the majority want. This interpretation of popular control fits uncomfortably with insights from social choice theory; some commentators—Riker, most famously—have argued that these insights should make us abandon the idea of popular rule as traditionally (...) understood. This article presents a formal theory of popular control that responds to the challenge from social choice theory. It makes precise a sense in which majorities may be said to have control even if the majority preference relation has an empty core. And it presents a simple game-theoretic model to illustrate how majorities can exercise control in this specified sense, even when incumbents are engaged in purely re-distributive policymaking and the majority rule core is empty. (shrink)

I will characterize the utilitarian and maximin rules of social choice game-theoretically. That is, I will introduce games whose solutions are the utilitarian and maximin distributions respectively. Then I will compare the rules by exploring similarities and differences between these games. This method of comparison has been carried out by others. But I characterize the two rules using games that involve bargaining within power structures. This new characterization better highlights the ethical differences between the rules.

Most political liberals argue that only rules, policies and institutions that are part of society’s basic structure need to be justified with so-called public reasons. Laws enacted outside this set are legitimate if and when public reasons can justify the procedure that selects them. I argue that this view is susceptible to known problems from social choice theory. However, there are resources within political liberalism that could address them. If the scope of public reason is extended beyond the (...) basic structure it could order people’s preferences in a way that circumvents the identified issues. (shrink)

Legal decision-making emphasizes, in a very self-conscious way, the justificatory significance of reasons. This paper argues that the obligation to provide reasons for choices, which must be articulated and structured around a set of generally shared and publicly comprehensible categories of thought, can serve to make the space of possible choices ‘concept sensitive’ in a very useful way. In particular, concept sensitivity has the effect of restricting certain movements within the choice space so that some of the systematic difficulties (...) in achieving an equilibrium in social choice which arise out of an excess of rational doing are avoided. The resulting equilibrium is path dependent. But because it is dependent on a choice path which ‘makes sense’ (or is ordered by thought precisely because it is concept sensitive), it is not the sort of arbitary path-dependent social choice which originally concerned Kenneth Arrow. This paper illustrates these points with examples from criminal law procedure, contract law and constitutional law. (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.

In Arrovian social choice theory assuming the independence of irrelevant alternatives, Murakami (1968) proved two theorems about complete and transitive collective choice rules that satisfy strict non-imposition (citizens’ sovereignty), one being a dichotomy theorem about Paretian or anti-Paretian rules and the other a dictator-or-inverse-dictator impossibility theorem without the Pareto principle. It has been claimed in the later literature that a theorem of Malawski and Zhou (1994) is a generalization of Murakami’s dichotomy theorem and that Wilson’s (1972) impossibility (...) theorem is stronger than Murakami’s impossibility theorem, both by virtue of replacing Murakami’s assumption of strict non-imposition with the assumptions of non-imposition and non-nullness. In this note, we first point out that these claims are incorrect: non-imposition and non-nullness are together equivalent to strict non-imposition for all transitive collective choice rules. We then generalize Murakami’s dichotomy and impossibility theorems to the setting of incomplete social preference. We prove that if one drops completeness from Murakami’s assumptions, his remaining assumptions imply (i) that a collective choice rule is either Paretian, anti-Paretian, or dis-Paretian (unanimous individual preference implies noncomparability) and (ii) that adding proposed constraints on noncomparability, such as the regularity axiom of Eliaz and Ok (2006), restores Murakami’s dictator-or-inverse-dictator result. (shrink)

This paper provides an ethical intepretation of the Nash choice rule. In a setting in which (cardinal) utilities are interpersonally comparable, this procedure is characterised by an impartiality requirement and by the assumption that choices are not responsive to the agents' relative ability to convert resources into utility.

Suzumura consistency is a necessary and sufficient condition for the existence of a weak-order extension. This paper provides some remarks on collective choice rules that generate Suzumura consistent social preferences. We examine the properties of such collective choice rules by introducing a procedural condition on collective choice rules. As applications of the procedural condition, we first investigate the decisive structure of a Paretian collective choice rule, and then consider the assignment of individual rights. In (...) our analysis, the concept of semi-decisiveness works effectively. (shrink)

In ‘Normative Uncertainty as a Voting Problem’, William MacAskill argues that positive credence in ordinal-structured or intertheoretically incomparable normative theories does not prevent an agent from rationally accounting for her normative uncertainties in practical deliberation. Rather, such an agent can aggregate the theories in which she has positive credence by methods borrowed from voting theory—specifically, MacAskill suggests, by a kind of weighted Borda count. The appeal to voting methods opens up a promising new avenue for theories of rational choice (...) under normative uncertainty. The Borda rule, however, is open to at least two serious objections. First, it seems implicitly to ‘cardinalize’ ordinal theories, and so does not fully face up to the problem of merely ordinal theories. Second, the Borda rule faces a problem of option individuation. MacAskill attempts to solve this problem by invoking a measure on the set of practical options. But it is unclear that there is any natural way of defining such a measure that will not make the output of the Borda rule implausibly sensitive to irrelevant empirical features of decision-situations. After developing these objections, I suggest an alternative: the McKelvey uncovered set, a Condorcet method that selects all and only the maximal options under a strong pairwise defeat relation. This decision rule has several advantages over Borda and mostly avoids the force of MacAskill’s objection to Condorcet methods in general. (shrink)

By applying Arrow’s impossibility theorem for social choice to scientific theory choice, Okasha concludes that there is no acceptable theory choice rule. Okasha identifies the only way out of the impossibility in enriching the input for the theory choice rule, following Sen’s work for social choice. However, such a route seems not to be available for ‘large scale’ theory choices—i.e. choices among ‘key theories’ which imply a change of paradigm—based on Kuhn’s (...) criteria, since these criteria cannot provide a richer input. The aim of the paper is to explore two lines of response to this conclusion. The first response proposes an example suggesting that Kuhn’s criteria may, indeed, provide sufficiently rich inputs. The second one proposes to use Kuhn’s criteria to evaluate prior probability and likelihood of the theories, and then take these as elements of the ‘Bayesian theory choice rule’ that avoids the impossibility. I will then argue against an objection to the second response, derived from Stegenga’s observation that a rule that translates the information provided by Kuhn’s criteria into prior probabilities suffers from Arrovian impossibility. Finally, I will answer a separate interesting question suggested by Stegenga’s observation. (shrink)

John Rawls famously argued that the Difference Principle would be chosen by any rational agent in the original position. Derek Parfit and Philippe Van Parijs have claimed, contra Rawls, that it is not the Difference Principle which is implied by Rawls’ original position argument, but rather the more refined Lexical Difference Principle. In this paper, we study both principles in the context of social choice under ignorance. First, we present a general format for evaluating original position arguments in (...) this context. We argue that in this format, the Difference Principle can be specified in three conceptually distinct ways. We show that these three specifications give the same choice recommendations, and can be grounded in an original position argument in combination with the well-known maximin rule. Analogously, we argue that one can give at least four plausible specifications of the Lexical Difference Principle, which however turn out to give different recommendations in concrete choice scenarios. We prove that only one of these four specifications can be grounded in an original position argument. Moreover, this one specification seems the least appealing from the viewpoint of distributive justice. This insight points towards a general weakness of original position arguments. (shrink)

This paper provides a philosophical critique of social choice theory insofar as it deals with the normative evaluation of voting and voting rules. I will argue that the very method of evaluating voting rules in terms of whether they satisfy various conditions is deeply problematic because introducing strategic behaviour leads to a violation of any condition that makes a difference between voting rules. I also argue that it is legitimate to make interpersonal comparisons of utilities in voting theory. (...) Combining a realistic account of voters’ behaviour with a utilitarian evaluation of the outcomes then leads to the judgment that strategic voting is beneficial. If it is, then Arrow's theorem does not have far-reaching consequences for democracy because one of its conditions is not normatively acceptable. (shrink)

The choice of a social decision rule for a federal assembly affects the welfare distribution within the federation. But which decision rules can be recommended on welfarist grounds? In this paper, we focus on two welfarist desiderata, viz. (i) maximizing the expected utility of the whole federation and (ii) equalizing the expected utilities of people from different states in the federation. We consider the European Union as an example, set up a probabilistic model of decision making and (...) explore how different decision rules fare with regard to the desiderata. We start with a default model, where the interests, and therefore the votes of the different states are not correlated. This default model is then abandoned in favor of models with correlations. We perform computer simulations and find that decision rules with a low acceptance threshold do generally better in terms of desideratum (i), whereas the rules presented in the Accession Treaty and in the (still unratified) Constitution of the European Union tend to do better in terms of desideratum (ii). The ranking obtained regarding desideratum (i) is fairly stable across different correlation patterns. (shrink)

The choice of a social decision rule for a federal assembly affects the welfare distribution within the federation. But which decision rules can be recommended on welfarist grounds? In this paper, we focus on two welfarist desiderata, viz. (i) maximizing the expected utility of the whole federation and (ii) equalizing the expected utilities of people from dif- ferent states in the federation. We consider the European Union as an example, set up a probabilistic model of decision making (...) and explore how different decision rules fare with regard to the desiderata. We start with a default model, where the interests, and therefore the votes of the different states are not correlated. This default model is then abandoned in favor of models with correlations. We perform computer simulations and find that decision rules with a low acceptance threshold do generally better in terms of desideratum (i), whereas the rules presented in the Accession Treaty and in the (still unratified) Constitution of the Euro- pean Union tend to do better in terms of desideratum (ii). The ranking obtained regarding desideratum (i) is fairly stable across different corre- lation patterns. (shrink)

Current arguments to increase shareholder power in the large public U.S. corporation need to take account of the well-established historical practice of extensive delegation by shareholders of business decision-making and agenda-control to management and the board, what might be characterized as an absolute delegation rule. This practice sharply limits the power of shareholders to put either business or governance proposals to the shareholders for dispositive resolution. The paper, originally published in 1991 but newly relevant, argues that the rule (...) is based on potential pathologies in shareholder voting rather than the inherent information asymmetry between shareholders and managers. Rational shareholders who know of this asymmetry (and know that others know) would simply vote against most shareholder proposals. But shareholder voting gives rise to potential cycling problems, as shifting shareholder majorities vie for preferred policies, and potential opportunism, as shareholders engage in side deals with management and other shareholders to extract rents in corporate decision-making. Since shareholding patterns are in part a response to control rights, deviations from the absolute delegation rule will predictably lead to greater block ownership, for defensive and offensive reasons. These concerns need to be addressed in arguments for the expansion of shareholder power. (shrink)

We discuss the relationships between positional rules (such as plurality and approval voting as well as the Borda count), Dodgson’s, Kemeny’s and Litvak’s methods of reaching consensus. The discrepancies between methods are seen as results of different intuitive conceptions of consensus goal states and ways of measuring distances therefrom. Saari’s geometric methodology is resorted to in the analysis of the consensus reaching methods.

Left freely to themselves, a group of rational individuals often fail to cooperate even when the product of social cooperation is beneficial to all. Hence, the author argues, a rule of collective decision making is clearly needed that specifies how social cooperation should be organised among contributing individuals. Suzumura gives a systematic presentation of the Arrovian impossibility theorems of social choice theory, so as to describe and enumerate the various factors that are responsible for the (...) stability of the voluntary association of free and rational individuals. Among other topics covered are an axiomatic characterisation of the concept of a rational choice, the simple majority decision rule and its extensions, the social choice implications of the concept of equity as nonenvy, the constrained majoritarian collective choice rules and the conflict between the Paretian ethics and the libertarian claims of individual rights. (shrink)

A collective choice mechanism can be viewed as a game in normal form; in this article it is shown, for very attractive rules and for sets with any number of alternatives, how individuals involved in a collective decision problem can construct the preferences they choose to express. An example is given with a version of plurality rule. Manipulability results are deduced from such a characterization.

One of the main results in topological social choice states the non-existence of a continuous, anonymous, and unanimous aggregation rule on spheres. This note provides a proof based upon simple methods such as integration.

Social choice rules are often evaluated and compared by inquiring whether they satisfy certain desirable criteria such as the Condorcet criterion, which states that an alternative should always be chosen when more than half of the voters prefer it over any other alternative. Many of these criteria can be formulated in terms of choice sets that single out reasonable alternatives based on the preferences of the voters. In this paper, we consider choice sets whose definition merely (...) relies on the pairwise majority relation. These sets include the Copeland set, the Smith set, the Schwartz set, von Neumann-Morgenstern stable sets, the Banks set, and the Slater set. We investigate the relationships between these sets and completely characterize their computational complexity, which allows us to obtain hardness results for entire classes of social choice rules. (shrink)

In a democracy, citizens should have some control over how they are governed. If they do not participate directly in making policy, they ought to maintain control over the public officials who design policy on their behalf. Rule by Multiple Majorities develops a novel theory of popular control: an account of what it is, why democracy's promise of popular control is compatible with what we know about actual democracies, and why it matters. While social choice theory suggests (...) there is no such thing as a 'popular will' in societies with at least minimal diversity of opinion, the author argues that multiple, overlapping majorities can nonetheless have control, at the same time. After resolving this conceptual puzzle, the author explains why popular control is a realistic and compelling ideal for democracies, notwithstanding voters' low levels of information and other shortcomings. (shrink)

There has been a significant interest in the recent literature in developing a solution to the problem of theory choice which is both normative and descriptive, but agent-based rather than rule-based, originating from Pierre Duhem’s notion of ‘good sense’. In this paper we present the properties Duhem attributes to good sense in different contexts, before examining its current reconstructions advanced in the literature and their limitations. We propose an alternative account of good sense, seen as promoting social (...) consensus in science, and show that it is superior to its rivals in two respects: it is more faithful to Duhemian good sense, and it cashes out the effect that virtues have on scientific progress. We then defend the social consensus account against objections that highlight the positive role of diversity and division of labour in science. (shrink)

This paper reports a preliminary sketch of a framework for integrating perspectives on economics, ethics, strategy, and stakeholders (Jones, 1995). It may notbe desirable in management practice to separate such considerations (Harris & Freeman, 2008). There are three general types of collective choice institutions: governments, markets, and voluntary associations. There are four general types of moral theory: moral rules (Kantianism), consequentialism (utilitarianism), virtuousness (bundling virtue theory, religion, and moral intuitionism), and social contract. There are three general positions concerning (...) social responsibilities of individuals and corporations (i.e., a licensed group of individuals). One position asserts zero social responsibility beyond compliance with laws. The polar-opposite position asserts significant social responsibilities by moral obligation. An intermediate position asserts social responsibility by agent cost-benefit analysis. The framework seeks to map these types of institutions, moral theories, and social responsibility conceptions relative to one another. The purpose is to see whether insight can be obtained concerning certain key developing debates. The paper explores implications of the work of Ostrom and Williamson (winners of the 2009 Nobel Prize in Economic Sciences) for this framework. That work addresses choice institutions—to which moral theories and social responsibility theories can be added. (shrink)

Assorted fruit from forty years' writing, these essays by David Braybrooke discuss (in Part One of the book) a variety of concrete, practical topics that ethical concerns bring into politics: people's interests; their needs as well as their preferences; their work and their commitment to work; their participation in politics and in other group activities. Essays follow on the justice with which theme matters are arranged for and on the common good in which they are consolidated. Justice here inspires a (...) 'departures' approach, which moves from agreement on departures from commutative justice to agreement on measures of distributive justice needed to forestall such departures. Another essay (first published here) radically undermines the odd but entrenched belief that utilitarianism classically licenced, even prescribed, systematically sacrificing the happiness of some people to give others greater pleasure. Part II and Part III of the book concentrate upon the subject of settled social rules, which are devices for securing the objectives treated in Part I. Part II shows that rules are ubiquitous in ethics, since there are no virtues without rules, just as there are no (justified) rules; without virtues. Part Two also shows that rules are as ubiquitous in social phenomena as the causal regularities sought by one school of social science. Part III captures the dialectic of history at least in part by a logical analysis of changes in rules following the onset of quandaries. It then considers how political choices can be both prudent, by keeping within duly considered incremental limits, and yet imaginative enough to escape the recent embarrassments generated by social choice theory. Characteristically versatile in topic and style, Braybrooke offers original light on all theme subjects. One reader has commented, ' His] prose is elegant and always a pleasure to read. Some of the pieces are nothing short of brilliant.' Which did the reader have in mind? Readers may differ (they already have) on just which pieces they would rank highest. (shrink)

The Condorcet efficiency of a social choice procedure is usually defined as the probability that this procedure coincides with the majority winner (or majority ordering) in random samples, given a majority winner exists (or given the majority ordering is transitive). Consequently, it is in effect a conditional probability that two sample statistics coincide, given certain side conditions. We raise a different issue of Condorcet efficiencies: What is the probability that a social choice procedure applied to a (...) sample matches with the majority preferences of the population from which the sample was drawn? We investigate the canonical case where the sample statistic is itself also majority rule and the samples are drawn from real world distributions gathered from national election surveys in Germany, France, and the United States. We relate the results to the existing literature on majority cycles and social homogeneity. We find that these samples rarely display majority cycles, whereas the probability that a sample misrepresents the majority preferences of the underlying population varies dramatically and always exceeds the probability that the sample displays cyclic majority preferences. Social homogeneity plays a fundamental role in the type of Condorcet efficiency investigated here. (shrink)

This article is featured in a special issue dedicated to theme, "the human being in the digital era: awareness, critical thinking and political space in the age of the internet and artificial intelligence." In this article, I consider the way that social-media companies nudge us to spend more time on their platforms, and I argue that, in principle, these nudges are morally permissible: they are not manipulative and do not violate any obvious moral rules. The moral problem, I argue, (...) is not with nudging in principle but is instead with the fact that users are being nudged towards something bad for them. In practice, this often involves being nudged to spend an unhealthy amount of time using a social-media app or being nudged towards content that is bad for us, such as by promoting eating-disorder content to young girls. Since nudging is morally permissible, it is open to these companies to use the same technologies to nudge us towards the good. (shrink)

This paper offers an account of the important role which an obligation to provide reasons can play in avoiding some of the systematic difficulties encountered in the theory of rational social choice. The paper builds on some of the insights offered by theories of structure-induced equilibrium. It argues that the obligation to provide reasons for certain choices, reasons which must be articulated and structured around a set of generally shared and publicly comprehensible categories of thought, can serve to (...) make the space of possible choices "concept-sensitive" in a very useful way. Concept-sensitivity has the effect of restricting certain movements within the choice space so that some of the difficulties for achieving an equilibrium in social choice, difficulties which arise out of an excess of rational doing, are avoided. The resulting equilibrium is path dependent, of course, but because it is dependent on a choice path which "makes sense" (or is ordered by thought precisely because it is concept-sensitive), it is not the sort of arbitrary path dependent social choice which was of such concern to Kenneth Arrow in his original Nobel prize winning work. The paper illustrates its points with examples taken from the law. The law is a method of making social choices which emphasizes (in a very self-conscious way, and one which has no parallel either in politics or the market) the justificatory significance of the obligation to give publicly accountable reasons which attend to those issues arising in an ordered way out of a highly structured adjudicative process. Thus, the paper has as one of its ambitions the bringing together of two accounts of rational decision-making which, to this point at least, have not had much contact, namely, the theory of rational social choice and the theory of legal reasoning. (shrink)

We characterize seniority rules, also known as lexical dictatorships, under weak consistency constraints on the group’s choice function. These constraints are base triple-acyclicity in the case of binary choices and rationalizability (although not rationality) in the case of choices between an arbitrary number of alternatives. Existing results on these weakened constraints remain silent on the treatment of the group’s most junior individuals and therefore do not yield a complete characterization of seniority rules. We also impose a universal domain, binary (...) strict Pareto optimality, binary Pareto indifference, binary independence of irrelevant alternatives, and the newly introduced condition of conflict resolution. The latter condition requires a social choice rules not to remain indecisive between alternatives for which individuals have conflicting preferences. (shrink)

Sparked by a remarkable result due to Hemaspaandra et al. [9], the voting rule attributed to Charles Dodgson has become one of the most studied voting rules in computational social choice. However, the computer science literature often neglects that Dodgson's rule has some serious shortcomings as a choice procedure. This short note contains four examples revealing Dodgson's deficiencies.

My dissertation focuses on problems that arise when a group makes decisions that are in reasonable ways connected to the beliefs and values of the group members. These situations are represented by models of decision-theoretic aggregation: Suppose a model of individual rationality in decision-making applies to each of a group of agents. Suppose this model also applies to the group as a whole, and that this group model is aggregated from the individual models. Two questions arise. First, what sets of (...) reasonable conditions can we consistently impose on the aggregation? Second, what can we learn from insights gained in such models, in particular for ethics and political philosophy? The dissertation has three parts, each using a different model of individual rationality. Each part contains essays addressing questions of either the first or the second kind with regard to its underlying model. Part I uses a social-choice-theoretic model, in which agents are only assumed to rank alternatives. Arrow's "Impossibility Theorem" shows that certain conditions that it would be natural to impose on all aggregation cannot be so imposed, on pain of contradiction. I discuss the impact of this result on the evaluation of majority rule and on democratic theory. I also discuss Sen's "Liberal Paradox", which addresses the possibility of incorporating rights into a social-choice theoretic model. Part II uses the von Neumann/Morgenstern theory of expected utility. A result under this model has been regarded as providing an argument for utilitarianism. I locate a place within utilitarianism where the theorem can do some work. To prepare the ground, I interpret the von Neumann/Morgenstern theory as part of a theory of deliberation. Thereby, this version of expected utility theory can be embedded into the philosophy of practical reasoning. The underlying model in Part III is Bayesian decision theory. Whereas the other two inquiries focus on the philosophical assessment of formal results, the third makes a formal contribution. One essay surveys the area, and a second explores a curious phenomenon that occurs in determining outcomes under one type of Bayesian aggregation. (shrink)

This article combines Social Choice Theory with Discrete Optimization. We assume that individuals have preferences over edges of a graph that need to be aggregated. The goal is to find a socially “best” spanning tree in the graph. As ranking all spanning trees is becoming infeasible even for small numbers of vertices and/or edges of a graph, our interest lies in finding algorithms that determine a socially “best” spanning tree in a simple manner. This problem is closely related (...) to the minimum (or maximum) spanning tree problem in Discrete Optimization. Our main result shows that for the various underlying ranking rules on the set of spanning trees discussed in this article, the sets of “best” spanning trees coincide. Moreover, a greedy algorithm based on a transitive group ranking on the set of edges will always provide such a “best” spanning tree. (shrink)

The surprise minimization principle has been applied to explain various cognitive processes in humans. Originally describing perceptual and active inference, the framework has been applied to different types of decision making including long-term policies, utility maximization and exploration. This analysis extends the application of surprise minimization to a multi-agent setup and shows how it can explain the emergence of social rules and cooperation. We further show that in social decision-making and political policy design, surprise minimization is superior in (...) many aspects to the classical approach of maximizing utility. Surprise minimization shows directly what value freedom of choice can have for social agents and why, depending on the context, they enter into cooperation, agree on social rules, or do nothing of the kind. (shrink)

Philip Pettit has drawn together here a series of interconnected essays on three subjects to which he has made notable contributions. The first part of the book discusses the rule-following character of thought. The second considers how choice can be responsive to different sorts of factors, while still being under the control of thought and the reasons that thought marshals. The third examines the implications of this view of choice and rationality for the normative regulation of (...) class='Hi'>social behaviour. Rules, Reasons, and Norms makes original and illuminating connections across a large swathe of territory, from metaphysics to philosophical psychology to the theory of rational regulation. (shrink)

This book represents a considerable revision and expansion of Public Choice II. Six new chapters have been added, and several chapters from the previous edition have been extensively revised. The discussion of empirical work in public choice has been greatly expanded. As in the previous editions, all of the major topics of public choice are covered. These include: why the state exists, voting rules, federalism, the theory of clubs, two-party and multiparty electoral systems, rent seeking, bureaucracy, interest (...) groups, dictatorship, the size of government, voter participation, and political business cycles. Normative issues in public choice are also examined including a normative analysis of the simple majority rule, Bergson–Samuelson social welfare functions, the Arrow and Sen impossibility theorems, Rawls's social contract theory and the constitutional political economy of Buchanan and Tullock. (shrink)

Is it rational to be moral? How do rationality and morality fit together with being human? These questions are at the heart of David Schmidtz's exploration of the connections between rationality and morality. This inquiry leads into both metaethics and rational choice theory, as Schmidtz develops conceptions of what it is to be moral and what it is to be rational. He defends a fairly expansive conception of rational choice, considering how ends as well as means can be (...) rationally chosen and explaining the role of self-imposed constraints in a rational life plan. His moral theory is dualistic, ranging over social structure as well as personal conduct and building both individual and collective rationality into its rules of recognition for morals. To the "why be moral" question, Schmidtz responds that being moral is rational, but he does not assume we have reasons to be rational. Instead, Schmidtz argues that being moral is rational in a particular way and that beings like us in situations like ours have reasons to be rational in just that way. This approach allows him to identify decisive reasons to be moral; at the same time, it explains why immorality is as prevalent as it is. This book thus offers a set of interesting and realistic conclusions about how morality fits into the lives of humanly rational agents operating in an institutional context like our own. (shrink)

Pettit presents a selection of essays touching upon metaphysics, philosophical psychology, and the theory of rational regulation. The first part of the book discusses the rule-following character of thought. The second considers how choice can be responsive to different sorts of factors, while still being under the control of thought. The third examines the implications of this view of choice and rationality for the normative regulation of social behavior.

The paper pores over the recent conceptions of normative judgement developed against the background of advances in psychology and neuroscience. It begins by analyzing what normative claim of morality and law consists of before presenting and criticizing the Social Intuitionist Model of normative judgement developed by Jonathan Haidt. The model poses serious challenges for well-established normative concepts, and the concept of normativity as objective reason for action in particular. A question is asked of what the relationship between philosophical conceptions (...) and the findings of neuroscience should be. The conclusion is that, in the face of new scientific facts, philosophers have no choice but to carefully revise their conceptual schemes. (shrink)