Kenneth Arrow’s “impossibility” theorem—or “general possibility” theorem, as he called it—answers a very basic question in the theory of collective decision-making. Say there are some alternatives to choose among. They could be policies, public projects, candidates in an election, distributions of income and labour requirements among the members of a society, or just about anything else. There are some people whose preferences will inform this choice, and the question is: which procedures are there for deriving, from what is known or (...) can be found out about their preferences, a collective or “social” ordering of the alternatives from better to worse? The answer is startling. Arrow’s theorem says there are no such procedures whatsoever—none, anyway, that satisfy certain apparently quite reasonable assumptions concerning the autonomy of the people and the rationality of their preferences. The technical framework in which Arrow gave the question of social orderings a precise sense and its rigorous answer is now widely used for studying problems in welfare economics. The impossibility theorem itself set much of the agenda for contemporary social choice theory. Arrow accomplished this while still a graduate student. In 1972, he received the Nobel Prize in economics for his contributions. (shrink)

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)

Pettit and List argue for realism about group agency, while at the same time try to retain a form of metaphysical and normative individualism on which human beings qualify as natural persons. This is an unstable and untenable combination of views. A corrective is offered here, on which realism about group agency leads us to the following related conclusions: in cases of group agency, the sort of rational unity that defines individual rational unity is realized at the level of a (...) whole group; rational unity is never a metaphysical given but always a product of effort and will; just as it can be realized within groups of human beings it can also be realized within parts of human beings, as well as within whole human lives; in cases of group agency, the rational unity that is achieved at the level of the group typically precludes rational unity at the level of its human constituents within their whole lives, though it can be realized within parts of those human lives. Along the way, a contrast is drawn between cases of genuine group agency and the cases of political agency envisaged by Rousseau and Rawls (and by Pettit and List) which leave individual human beings intact as separate agents in their own rights. (shrink)

This paper offers a comparison of three different kinds of collective attitudes: aggregate, common, and corporate attitudes. They differ not only in their relationship to individual attitudes—e.g., whether they are “reducible” to individual attitudes—but also in the roles they play in relation to the collectives to which they are ascribed. The failure to distinguish them can lead to confusion, in informal talk as well as in the social sciences. So, the paper’s message is an appeal for disambiguation.

The paradoxes and dilemmas of social choice theory can be taken as an argument against a certain view of democracy: For the identity theory democracy represents a collective actor standing for aggregated individual interests. According to a second model of society, democracy has its normative basis in structural traits of interaction and cooperation. Within the formal theory of politics both the Arrow-Theorem and the Liberal Paradox undermine the identity theory and give us reasons for the second, the normative theory which (...) takes democracy as being constituted by structural rules. (shrink)

Is it possible that all of the social sciences could employ a common methodology? If so, what would it be? This article adresses these questions. It takes off from James Coleman’s recent book, The Foundations of Social Theory. Coleman’s social theory is built on the postulate that individuals are rational actors, the same postulate that most of modern economics is built upon. This article critiques the use of this postulate in economics, and thus questions whether it is a useful building (...) block for the methodological foundations of social science research. It proposes an adaptive view of human behavior as an alternative in which preferences are conditioned by past experience. The work of Joseph Schumpeter is discussed as an exemplar of the methodology advocated here. (shrink)

Suppose several individuals (e.g., experts on a panel) each assign probabilities to some events. How can these individual probability assignments be aggregated into a single collective probability assignment? This article reviews several proposed solutions to this problem. We focus on three salient proposals: linear pooling (the weighted or unweighted linear averaging of probabilities), geometric pooling (the weighted or unweighted geometric averaging of probabilities), and multiplicative pooling (where probabilities are multiplied rather than averaged). We present axiomatic characterisations of each class of (...) pooling functions (most of them classic, but one new) and argue that linear pooling can be justified procedurally, but not epistemically, while the other two pooling methods can be justified epistemically. The choice between them, in turn, depends on whether the individuals' probability assignments are based on shared information or on private information. We conclude by mentioning a number of other pooling methods. (shrink)

This article examines the methodology of a core branch of contemporary political theory or philosophy: “analytic” political theory. After distinguishing political theory from related fields, such as political science, moral philosophy, and legal theory, the article discusses the analysis of political concepts. It then turns to the notions of principles and theories, as distinct from concepts, and reviews the methods of assessing such principles and theories, for the purpose of justifying or criticizing them. Finally, it looks at a recent debate (...) on how abstract and idealized political theory should be, and assesses the significance of disagreement in political theory. The discussion is carried out from an angle inspired by the philosophy of science. (shrink)

A platitude that took hold with Kuhn is that there can be several equally good ways of balancing theoretical virtues for theory choice. Okasha recently modelled theory choice using technical apparatus from the domain of social choice: famously, Arrow showed that no method of social choice can jointly satisfy four desiderata, and each of the desiderata in social choice has an analogue in theory choice. Okasha suggested that one can avoid the Arrow analogue for theory choice by employing a strategy (...) used by Sen in social choice, namely, to enhance the information made available to the choice algorithms. I argue here that, despite Okasha’s claims to the contrary, the information-enhancing strategy is not compelling in the domain of theory choice. (shrink)

Despite its several variations, the central position of equipoise is that subjects in clinical experiments should not be randomized to conditions when others believe that better alternatives exist. This position has been challenged over issues of which group in the medical or research community is authorized to make that determination, and it has been argued that informed consent provides sufficient ethical protection for participants independent of equipoise. In this paper I frame ethical participation in clinical research as a two-party decision (...) process involving offering and accepting participation under informed consent. Nine conditions are identified in which it is possible that potential participants and researchers or care professionals can rationally choose divergent actions based on identical understandings of the situation. Under such circumstances, researchers or care professionals cannot ethically substitute their understanding of equipoise in the situation for the patients’ choices, or vice versa. (shrink)

We investigate the family of concepts that an agent comes to know through a set of defining features, and examine the role played by these features in the process of categorization. In a qualitative framework, categorial membership is evaluated through an order relation among the objects at hand, which translates the fact that an object may fall more than another under a given concept. For concepts defined by their features, this global membership order depends on the degree with which each (...) feature applies to the objects of the universe. The passage from these individual membership degrees to a global membership order poses a problem analogous to vote aggregation in social choice theory. This similarity leads to an original solution that is particularly well-adapted to the framework of cognitive psychology. The resulting membership order extends to compound concepts, and provides a good description of the guppy paradox and the conjunction effect. (shrink)

Most approaches to iterated belief revision are accompanied by some motivation for the use of the proposed revision operator (or family of operators), and typically encode enough information in the epistemic state of an agent for uniquely determining one-step revision. But in those approaches describing a family of operators there is usually little indication of how to proceed uniquely after the first revision step. In this paper we contribute towards addressing that deficiency by providing a formal framework which goes beyond (...) the first revision step in two ways. First, the framework is obtained by enriching the epistemic state of an agent starting from the following intuitive idea: we associate to each world x two abstract objects x⁺ and x⁻, and we assume that, in addition to preferences over the set of worlds, we are given preferences over this set of objects as well. The latter can be considered as meta-information encoded in the epistemic state which enables us to go beyond the first revision step of the revision operator being applied, and to obtain a unique set of preferences over worlds. We then extend this framework to consider, not only the revision of preferences over worlds, but also the revision of this extended structure itself. We look at some desirable properties for revising the structure and prove the consistency of these properties by giving a concrete operator satisfying all of them. Perhaps more importantly, we show that this framework has strong connections with two other types of constructions in related areas. Firstly, it can be seen as a special case of preference aggregation which opens up the possibility of extending the frame-work presented here into a full-fledged framework for preference aggregation and social choice theory. Secondly, it is related to existing work on the use of interval orderings in a number of different contexts. (shrink)

This paper suggests the democratic direction in which the right of freedom of expression should be conceived and applied. In the first two sections it suggests some counter-examples to, and diagnoses of, the libertarian and liberal conceptions of freedom of expression, taking Scanlon (1972) and Scanlon (1979), respectively, to be their chief proponents. The paper suggests that these conceptions cannot take into account clear examples, like fraudulent propaganda, which should not be legal. The democratic conception takes it to heart that (...) the pillars upon which the right of freedom of expression is founded are individual and collective autonomy, the right to know facts of public interest and information necessary for effective democratic control of government. The paper suggests that in a time when private powers seriously threaten these pillars, it is correct for the government to step in to provide the framework in which genuine discussion geared toward fulfilling the objectives of these pillars can take place. (shrink)

The Pareto principle states that if the members of society express the same preference judgment between two options, this judgment is compelling for society. A building block of normative economics and social choice theory, and often borrowed by contemporary political philosophy, the principle has rarely been subjected to philosophical criticism. The paper objects to it on the ground that it indifferently applies to those cases in which the individuals agree on both their expressed preferences and their reasons for entertaining them, (...) and those cases in which they agree on their expressed preferences, while differing on their reasons. The latter are cases of "spurious unanimity", and it is normatively inappropriate, or so the paper argues, to defend unanimity preservation at the social level for them, so the Pareto principle is formulated much too broadly. The objection seems especially powerful when the principle is applied in an ex ante context of uncertainty, in which individuals can disagree on both their probabilities and utilities, and nonetheless agree on their preferences over prospects. (shrink)

Judgment aggregation theory, or rather, as we conceive of it here, logical aggregation theory generalizes social choice theory by having the aggregation rule bear on judgments of all kinds instead of merely preference judgments. It derives from Kornhauser and Sager’s doctrinal paradox and List and Pettit’s discursive dilemma, two problems that we distinguish emphatically here. The current theory has developed from the discursive dilemma, rather than the doctrinal paradox, and the final objective of the paper is to give the latter (...) its own theoretical development along the line of recent work by Dietrich and Mongin. However, the paper also aims at reviewing logical aggregation theory as such, and it covers impossibility theorems by Dietrich, Dietrich and List, Dokow and Holzman, List and Pettit, Mongin, Nehring and Puppe, Pauly and van Hees, providing a uniform logical framework in which they can be compared with each other. The review goes through three historical stages: the initial paradox and dilemma, the scattered early results on the independence axiom, and the so-called canonical theorem, a collective achievement that provided the theory with its specific method of analysis. The paper goes some way towards philosophical logic, first by briefly connecting the aggregative framework of judgment with the modern philosophy of judgment, and second by thoroughly discussing and axiomatizing the ‘general logic’ built in this framework. (shrink)

The paper analyses economic evaluations by distinguishing evaluative statements from actual value judgments. From this basis, it compares four solutions to the value neutrality problem in economics. After rebutting the strong theses about neutrality (normative economics is illegitimate) and non-neutrality (the social sciences are value-impregnated), the paper settles the case between the weak neutrality thesis (common in welfare economics) and a novel, weak non-neutrality thesis that extends the realm of normative economics more widely than the other weak thesis does.

Public deliberation has been defended as a rational and noncoercive way to overcome paradoxical results from democratic voting, by promoting consensus on the available alternatives on the political agenda. Some critics have argued that full consensus is too demanding and inimical to pluralism and have pointed out that single-peakedness, a much less stringent condition, is sufficient to overcome voting paradoxes. According to these accounts, deliberation can induce single-peakedness through the creation of a ‘meta-agreement’, that is, agreement on the dimension according (...) to which the issues at stake are ‘conceptualized’. We argue here that once all the conditions needed for deliberation to bring about single-peakedness through meta-agreement are unpacked and made explicit, meta-agreement turns out to be a highly demanding condition, and one that is very inhospitable to pluralism. (shrink)

John Harsanyi and John Rawls both used the veil of ignorance thought experiment to study the problem of choosing between alternative social arrangements. With his ‘impartial observer theorem’, Harsanyi tried to show that the veil of ignorance argument leads inevitably to utilitarianism, an argument criticized by Sen, Weymark and others. A quite different use of the veil-of-ignorance concept is found in evolutionary biology. In the cell-division process called meiosis, in which sexually reproducing organisms produce gametes, the chromosome number is halved; (...) when meiosis is fair, each gene has only a fifty percent chance of making it into any gamete. This creates a Mendelian veil of ignorance, which has the effect of aligning the interests of all the genes in an organism. This paper shows how Harsanyi's version of the veil-of-ignorance argument can shed light on Mendelian genetics. There turns out to be an intriguing biological analogue of the impartial observer theorem that is immune from the Sen/Weymark objections to Harsanyi's original. View HTML Send article to KindleTo send this article to your Kindle, first ensure [email protected] is added to your Approved Personal Document E-mail List under your Personal Document Settings on the Manage Your Content and Devices page of your Amazon account. Then enter the ‘name’ part of your Kindle email address below. Find out more about sending to your Kindle. Find out more about sending to your Kindle. Note you can select to send to either the @free.kindle.com or @kindle.com variations. ‘@free.kindle.com’ emails are free but can only be sent to your device when it is connected to wi-fi. ‘@kindle.com’ emails can be delivered even when you are not connected to wi-fi, but note that service fees apply. Find out more about the Kindle Personal Document Service.SOCIAL JUSTICE, GENOMIC JUSTICE AND THE VEIL OF IGNORANCE: HARSANYI MEETS MENDELVolume 28, Issue 1Samir Okasha DOI: https://doi.org/10.1017/S0266267112000119Your Kindle email address Please provide your Kindle [email protected]@kindle.com Available formats PDF Please select a format to send. By using this service, you agree that you will only keep articles for personal use, and will not openly distribute them via Dropbox, Google Drive or other file sharing services. Please confirm that you accept the terms of use. Cancel Send ×Send article to Dropbox To send this article to your Dropbox account, please select one or more formats and confirm that you agree to abide by our usage policies. If this is the first time you use this feature, you will be asked to authorise Cambridge Core to connect with your account. Find out more about sending content to Dropbox. SOCIAL JUSTICE, GENOMIC JUSTICE AND THE VEIL OF IGNORANCE: HARSANYI MEETS MENDELVolume 28, Issue 1Samir Okasha DOI: https://doi.org/10.1017/S0266267112000119Available formats PDF Please select a format to send. By using this service, you agree that you will only keep articles for personal use, and will not openly distribute them via Dropbox, Google Drive or other file sharing services. Please confirm that you accept the terms of use. Cancel Send ×Send article to Google Drive To send this article to your Google Drive account, please select one or more formats and confirm that you agree to abide by our usage policies. If this is the first time you use this feature, you will be asked to authorise Cambridge Core to connect with your account. Find out more about sending content to Google Drive. SOCIAL JUSTICE, GENOMIC JUSTICE AND THE VEIL OF IGNORANCE: HARSANYI MEETS MENDELVolume 28, Issue 1Samir Okasha DOI: https://doi.org/10.1017/S0266267112000119Available formats PDF Please select a format to send. By using this service, you agree that you will only keep articles for personal use, and will not openly distribute them via Dropbox, Google Drive or other file sharing services. Please confirm that you accept the terms of use. Cancel Send ×Export citation Request permission. (shrink)

We argue that a semantics for counterfactual conditionals in terms of comparative overall similarity faces a formal limitation due to Arrow’s impossibility theorem from social choice theory. According to Lewis’s account, the truth-conditions for counterfactual conditionals are given in terms of the comparative overall similarity between possible worlds, which is in turn determined by various aspects of similarity between possible worlds. We argue that a function from aspects of similarity to overall similarity should satisfy certain plausible constraints while Arrow’s impossibility (...) theorem rules out that such a function satisfies all the constraints simultaneously. We argue that a way out of this impasse is to represent aspectual similarity in terms of ranking functions instead of representing it in a purely ordinal fashion. Further, we argue against the claim that the determination of overall similarity by aspects of similarity faces a difficulty in addition to the Arrovian limitation, namely the incommensurability of different aspects of similarity. The phenomena that have been cited as evidence for such incommensurability are best explained by ordinary vagueness. (shrink)

Amartya Sen argues that for the advancement of justice identification of ‘perfect’ justice is neither necessary nor sufficient. He replaces ‘perfect’ justice with comparative justice. Comparative justice limits itself to comparing social states with respect to degrees of justice. Sen’s central thesis is that identifying ‘perfect’ justice and comparing imperfect social states are ‘analytically disjoined’. This essay refutes Sen’s thesis by demonstrating that to be able to make adequate comparisons we need to identify and integrate criteria of comparison. This is (...) precisely the aim of a theory of justice (such as John Rawls’s theory): identifying, integrating and ordering relevant principles of justice. The same integrated criteria that determine ‘perfect’ justice are needed to be able to adequately compare imperfect social states. Sen’s alternative approach, which is based on social choice theory, is incapable of avoiding contrary, indeterminate or incoherent directives where plural principles of justice conflict. (shrink)

The revelatory paper, “Dilemmas in the General Theory of Planning,” by Rittel and Webber (Policy Sci 4:155–169, 1973 ) has had great impact because it provides one example of an emergent consensus across many disciplines. Many “problems,” as addressed in real-world situations, involve elements that exceed the complexity of any known or hoped-for model, or are “wicked.” Many who encounter this work for the first time find that their concept of wicked problems aptly describes many environmental disputes. For those frustrated (...) with the lack of progress in many areas of environmental protection, Rittel and Webber’s work suggested a powerful explanatory hypothesis: Complex environmental problems cannot be comprehended within any of the accepted disciplinary models available in the academy or in discourses on public interest and policy. What should we conclude about the future of social improvements, and about the possibilities for rational discourse leading to cooperative action, with respect to this huge number of pressing public, environmental problems? Can we find ways to address environmental problems that improves the ability of communities to respond creatively and rationally to them? I will argue that, while the Rittel-Webber critique requires us to abandon many of the assumptions associated with a positivistic view of science and its applications to policy analysis, it also points to a more productive direction for the future of policy analysis. I will introduce “boundary critique,” developed within Critical Systems Theory (CST), an approach that offers some reason for optimism in dealing with some aspects of wickedness. (shrink)

Kuhn’s famous thesis that there is ‘no unique algorithm’ for choosing between rival scientific theories is analysed using the machinery of social choice theory. It is shown that the problem of theory choice as posed by Kuhn is formally identical to a standard social choice problem. This suggests that analogues of well-known results from the social choice literature, such as Arrow’s impossibility theorem, may apply to theory choice. If an analogue of Arrow’s theorem does hold for theory choice this would (...) refute Kuhn’s thesis, but it would also pose a threat to the rationality of science, a threat that is if anything more worrying than that posed by Kuhn. Various possible ‘escape routes’ from Arrow’s impossibility result are examined, in particular Amartya Sen’s idea of ‘enriching the informational basis’. It is shown that Sen’s idea can be applied to the problem of theory choice in science. This in turn sheds light on two well-known approaches to inductive inference in philosophy of science: Bayesianism and statistical model selection. (shrink)

This paper critically engages Philip Mirowki's essay, "The scientific dimensions of social knowledge and their distant echoes in 20th-century American philosophy of science." It argues that although the cold war context of anti-democratic elitism best suited for making decisions about engaging in nuclear war may seem to be politically and ideologically motivated, in fact we need to carefully consider the arguments underlying the new rational choice based political philosophies of the post-WWII era typified by Arrow's impossibility theorem. A distrust of (...) democratic decision-making principles may be developed by social scientists whose leanings may be toward the left or right side of the spectrum of political practices. (shrink)

This paper proposes an exploration of the methodology of utility functions that distinguishes interpretation from representation. While representation univocally assigns numbers to the entities of the domain of utility functions, interpretation relates these entities with empirically observable objects of choice. This allows us to make explicit the standard interpretation of utility functions which assumes that two objects have the same utility if and only if the individual is indifferent among them. We explore the underlying assumptions of such an hypothesis and (...) propose a non-standard interpretation according to which objects of choice have a well-defined utility although individuals may vary in the way they treat these objects in a specific context. We provide examples of such a methodological approach that may explain some reversal of preferences and suggest possible mathematical formulations for further research. (shrink)

A new Arrovian impossibility is obtained without invoking independence of irrelevant alternatives type assumptions. The new conditions leading to the impossibility are based on the concept of power of enforcement, and specify how this power can (see A3) or cannot be expanded (see A1, A2 and A4).

It is always possible to construct a real function f, given random quantities X and Y with continuous distribution functions F and G, respectively, in such a way that f(X) and f(Y), also random quantities, have both the same distribution function, say H. This result of De Finetti introduces an alternative way to somehow describe the `opinion' of a group of experts about a continuous random quantity by the construction of Fields of coincidence of opinions (FCO). A Field of coincidence (...) of opinions is a finite union of intervals where the opinions of the experts coincide with respect to that quantity of interest. We speculate on (dis)advantages of Fields of Opinion compared to usual `probability' measures of a group and on their relation with a continuous version of the well-known Allais' paradox. (shrink)

Sen's Liberal Paradox has received a good deal of attention in the literature. However, it is worth re-opening the discussion since the solutions offered so far have serious problems and since there is more to say about the nature of the problem displayed by the Liberal Paradox. I propose a new solution to the paradox in the following sense: First, I argue that its range of applicability is not very broad. Second, there is nothing paradoxical about a conflict of the (...) principles involved in the Liberal Paradox. (Nagel's thesis of the ``fragmentation of value'' is important to make this point.) Third, I make a recommendation about how to remove conflicts when they occur in a restricted class of cases. For the other cases, no recommendation of similar appeal is available. But in the light of the first point, the availability of a generally applicable recommendation was not to be expected. (shrink)

After reviewing the compelling case for separability (`social welfare is a separable function of individual utilities'), an argument is advanced for utilitarianism (defined as `social welfare is the unweighted sum of individual utilities'). Basically, a compelling individualism-type axiom leads us to (social welfare as an) unweighted sum (of individual utilities), given separability.

The integration of learning cognitive agents in the research agenda is an important step in the evolution of economics. However, relying on a retrospective analysis of the treatment of decision making in economics, this article argues that the cognitive programme aims to justify rational behaviour in an equilibrium framework rather than to integration an interpretative conception of agents' behaviour. As a consequence, the level of generality of analytical results remains limited and economists miss the opportunity to establish a discussion with (...) other social sciences. In particular, it fails to analyse a class of situations related to the problem of knowledge creation and the subsequent learning paradox. Building on recent advances in heterodox cognitive science, we suggest a behavioural approach that discriminates different learning situations. If applied, this approach would permit a better understanding of human behaviour and a richer analysis of coordination mechanisms in unfamiliar environment with no loss of rigour. (shrink)

I model sequential decisions over multiple interconnected propositions and investigate path-dependence in such decisions. The propositions and their interconnections are represented in propositional logic. A sequential decision process is path-dependent if its outcome depends on the order in which the propositions are considered. Assuming that earlier decisions constrain later ones, I prove three main results: First, certain rationality violations by the decision-making agent—individual or group—are necessary and sufficient for path-dependence. Second, under some conditions, path-dependence is unavoidable in decisions made by (...) groups. Third, path-dependence makes decisions vulnerable to strategic agenda setting and strategic voting. I also discuss escape routes from path-dependence. My results are relevant to discussions on collective consistency and reason-based decision-making, focusing not only on outcomes, but also on underlying reasons, beliefs, and constraints. (shrink)

Majority cycling and related social choice paradoxes are often thought to threaten the meaningfulness of democracy. But deliberation can prevent majority cycles – not by inducing unanimity, which is unrealistic, but by bringing preferences closer to single-peakedness. We present the first empirical test of this hypothesis, using data from Deliberative Polls. Comparing preferences before and after deliberation, we find increases in proximity to single-peakedness. The increases are greater for lower versus higher salience issues and for individuals who seem to have (...) deliberated more versus less effectively. They are not merely a byproduct of increased substantive agreement. Our results both refine and support the idea that deliberation, by increasing proximity to single-peakedness, provides an escape from the problem of majority cycling. (shrink)

Decision-making typically requires judgments about causal relations: we need to know the causal effects of our actions and the causal relevance of various environmental factors. We investigate how several individuals' causal judgments can be aggregated into collective causal judgments. First, we consider the aggregation of causal judgments via the aggregation of probabilistic judgments, and identify the limitations of this approach. We then explore the possibility of aggregating causal judgments independently of probabilistic ones. Formally, we introduce the problem of causal-network aggregation. (...) Finally, we revisit the aggregation of probabilistic judgments when this is constrained by prior aggregation of qualitative causal judgments. (shrink)

It is a platitude among decision theorists that agents should choose their actions so as to maximize expected value. But exactly how to define expected value is contentious. Evidential decision theory (henceforth EDT), causal decision theory (henceforth CDT), and a theory proposed by Ralph Wedgwood that this essay will call benchmark theory (BT) all advise agents to maximize different types of expected value. Consequently, their verdicts sometimes conflict. In certain famous cases of conflict—medical Newcomb problems—CDT and BT seem to get (...) things right, while EDT seems to get things wrong. In other cases of conflict, including some recent examples suggested by Andy Egan, EDT and BT seem to get things right, while CDT seems to get things wrong. In still other cases, EDT and CDT seems to get things right, while BT gets things wrong. It's no accident, this essay claims, that all three decision theories are subject to counterexamples. Decision rules can be reinterpreted as voting rules, where the voters are the agent's possible future selves. The problematic examples have the structure of voting paradoxes. Just as voting paradoxes show that no voting rule can do everything we want, decision-theoretic paradoxes show that no decision rule can do everything we want. Luckily, the so-called “tickle defense” establishes that EDT, CDT, and BT will do everything we want in a wide range of situations. Most decision situations, this essay argues, are analogues of voting situations in which the voters unanimously adopt the same set of preferences. In such situations, all plausible voting rules and all plausible decision rules agree. (shrink)

This is the introduction of the special issue,.

In this paper, I argue for a new normative theory of rational choice under risk, namely expected comparative utility (ECU) theory. I first show that for any choice option, a, and for any state of the world, G, the measure of the choiceworthiness of a in G is the comparative utility (CU) of a in G—that is, the difference in utility, in G, between a and whichever alternative to a carries the greatest utility in G. On the basis of this (...) principle, I then argue that for any agent, S, faced with any decision under risk, S should rank his or her decision options (in terms of how choiceworthy they are) according to their comparative expected comparative utility (CECU) and should choose whichever option carries the greatest CECU. For any option, a, a’s CECU is the difference between its ECU and that of whichever alternative to a carries the greatest ECU, where a’s ECU is a probability‐weighted sum of a’s CUs across the various possible states of the world. I lastly demonstrate that in some ordinary decisions under risk, ECU theory delivers different verdicts from those of standard decision theory. (shrink)

A conception of legitimacy is at the core of normative theories of democracy. Many different conceptions of legitimacy have been put forward, either explicitly or implicitly. In this article, I shall first provide a taxonomy of conceptions of legitimacy that can be identified in contemporary democratic theory. The taxonomy covers both aggregative and deliberative democracy. I then argue for a conception of democratic legitimacy that takes the epistemic dimension of public deliberation seriously. In contrast to standard interpretations of epistemic democracy, (...) however, the conception I put forward avoids procedure-independent standards of correctness. Instead, it relies on a procedural social epistemology and defines legitimacy entirely in terms of the fairness of procedures. I call this conception of democratic legitimacy `Pure Epistemic Proceduralism'. I shall argue that it should be preferred over `Rational Epistemic Proceduralism', the conception of legitimacy that underlies the standard interpretation of epistemic democracy. Key Words: legitimacy • deliberative democracy • epistemic democracy • social epistemology. (shrink)

How can the propositional attitudes of several individuals be aggregated into overall collective propositional attitudes? Although there are large bodies of work on the aggregation of various special kinds of propositional attitudes, such as preferences, judgments, probabilities and utilities, the aggregation of propositional attitudes is seldom studied in full generality. In this paper, we seek to contribute to filling this gap in the literature. We sketch the ingredients of a general theory of propositional attitude aggregation and prove two new theorems. (...) Our first theorem simultaneously characterizes some prominent aggregation rules in the cases of probability, judgment and preference aggregation, including linear opinion pooling and Arrovian dictatorships. Our second theorem abstracts even further from the specific kinds of attitudes in question and describes the properties of a large class of aggregation rules applicable to a variety of belief-like attitudes. Our approach integrates some previously disconnected areas of investigation. (shrink)

While a large social-choice-theoretic literature discusses the aggregation of individual judgments into collective ones, there is much less formal work on the transformation of judgments in group communication. I develop a model of judgment transformation and prove a baseline impossibility theorem: Any judgment transformation function satisfying some initially plausible conditions is the identity function, under which no opinion change occurs. I identify escape routes from this impossibility and argue that the kind of group communication envisaged by deliberative democats must be (...) "holistic": It must focus on webs of connected propositions, not on one proposition at a time, which echoes the Duhem-Quine "holism thesis" on scientific theory testing. My approach provides a map of the logical space in which different possible group communication processes are located. (shrink)