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)

Sen's "The Impossibility of a Paretian Liberal" was meant to crystallize his fundamental criticism against the welfaristic basis of welfare economics in general, and social choice theory in particular. This paper vindicates Sen's criticism, arguing that its logical relevance is not lost in light of recent criticisms against his method of articulating individual rights in terms of a person's decisive power in social choice. We show that some recent proposals that Sen's articulation failed to capture a strong libertarian tradition of (...) free contract and that an appropriate formulation of this tradition wipes off the Sen impossibility cannot be sustained. We then show that the game form articulation of rights casts serious doubts on the Sen articulation of liberty, but the Sen impossibility strenuously comes back in the context of realizing conferred game form rights as well as in the context of initial conferment of game form rights. (shrink)

This book takes a unique and compreheisve look at intergenerational equity and sustainability.

Ever since Sen criticized the notion of internal consistency of choice, there exists a widespread perception that the standard rationalizability approach to the theory of choice has difficulties in coping with the existence of external norms. We introduce a concept of norm-conditional rationalizability and show that external norms can be made compatible with the methods underlying the traditional rationalizability approach. To do so, we characterize norm-conditional rationalizability by means of suitable modifications of revealed preference axioms that are well established in (...) the theory of rational choice on general domains as analysed in contributions by Richter and Hansson, for example. We compare our approach to alternative suggestions that have appeared in response to Sen's criticisms, and we discuss its links to Sen's notion of self-imposed choice constraints. (shrink)

We examine the maximal-element rationalizability of choice functions with arbitrary domains. While rationality formulated in terms of the choice of greatest elements according to a rationalizing relation has been analyzed relatively thoroughly in the earlier literature, this is not the case for maximal-element rationalizability, except when it coincides with greatest-element rationalizability because of properties imposed on the rationalizing relation. We develop necessary and sufficient conditions for maximal-element rationalizability by itself, and for maximal-element rationalizability in conjunction with additional properties of a (...) rationalizing relation such as reflexivity, completeness, P-acyclicity, quasi-transitivity, consistency and transitivity. (shrink)

Although the theory of greatest-element rationalizability and maximal-element rationalizability on general domains and without full transitivity of rationalizing relations is well-developed in the literature, these standard notions of rational choice are often considered to be too demanding. An alternative definition of rationality of choice is that of non-deteriorating choice, which requires that the chosen alternatives must be judged at least as good as a reference alternative. In game theory, this definition is well-known under the name of individual rationality when the (...) reference alternative is construed to be the status quo. This alternative form of rationality of individual and social choice is characterized inthispaperongeneraldomainsandwithout full transitivity of rationalizing relations. (shrink)

This paper extends the classical extension theorem established by Edward Szpilrajn (Fundamenta Mathematicae, 16, pp. 386–389, 1930). Szpilrajn's theorem states that every quasi‐ordering has an ordering extension. Because of its usefulness in various themes of economics, it has been applied by many researchers. Important generalizations have been presented by two authors, Kenneth Arrow and Kotaro Suzumura, among others. First, we provide concise proofs of four extension theorems by Szpilrajn, Arrow and Suzumura. We then show an extension of (...) their extension theorems. (shrink)

This title offers an illustrated overview of the evolution of two very different strains of modern Japanese photography. In the 1930s, Japanese photography evolved in two very directions: one toward a documentary style, the other favouring an experimental, or avant-garde, approach strongly influence by Western Surrealism. This book explores these two divergent paths through the work of two remarkable figures: Hiroshi Hamaya and Kansuke Yamamoto. Hiroshi Hamaya was born and raised in Tokyo and, after an initial period of creative experimentation, (...) turned his attention to recording traditional life and culture. He went on to record cultural changes in China, political protests in Japan, and landscapes around the world. Kansuke Yamamoto became fascinated by the innovative approaches in art and literature exemplified by Western artists such as Man Ray and Magritte. 0Exhibition: Getty Museum, Los Angeles, USA. --. (shrink)

Mental imagery of movement is a potentially valuable rehabilitation task, but its therapeutic efficacy may depend on the specific cognitive strategy employed. Individuals use two main strategies to perform the hand mental rotation task, which involves determining whether a visual image depicts a left or right hand. One is the motor imagery strategy, which involves mentally simulating one’s own hand movements. In this case, task performance as measured by response time is subject to a medial–lateral effect wherein the RT is (...) reduced when the fingertips are directed medially, presumably as the actual motion would be easier. The other strategy is to employ visual imagery, which involves mentally rotating the picture and is not subject to this medial–lateral effect. The rehabilitative benefits of the HMRT are thought to depend on the MI strategy, so it is essential to examine the effects of individual factors such as age, image perspective, and innate ability on the strategy adopted. When presented with pictures of the palm, all subjects in the current study used the MI strategy, regardless of age and ability. In contrast, when subjects were presented with pictures of the back of the hand, the VI strategy predominated among the young age group regardless of performance, while the strategy used by middle-age and elderly groups depended on performance ability. In the middle-age and elderly groups, the VI approach predominated in those with high performance skill, whereas the MI strategy predominated among those with low performance skill. Thus, higher-skill middle-aged and elderly individuals may not necessarily form a motion image during the HMRT, potentially limiting rehabilitation efficacy. (shrink)

Objectives: This study aimed to conduct a systematic review and meta-analysis of randomized controlled trials (RCTs) to improve subjective well-being (SWB), including evaluative, hedonic, and eudemonic well-being, and the mental component of quality of life (QOL) of working population. Methods: A literature search was conducted, using PubMed, Embase, PsycINFO, and PsycARTICLES. Eligible studies included those that were RCTs of any intervention, conducted among healthy workers, measured SWB as a primary outcome, and original articles in English. Study characteristics, intervention, outcomes, and (...) results on SWB outcomes were extracted by the investigators independently. After a brief narrative summarizing and classifying the contents of the interventions, the included outcomes were categorized into each aspect of SWB (evaluative, hedonic, and eudemonic well-being, and the mental component of QOL). Finally, the characteristics of the effective interventions for increasing each aspect were summarized, and the pooled effect of interventions on SWB was investigated by a meta-analysis. Publication bias was investigated by drawing a funnel plot and conducting Egger's test. Results: From the 5,450 articles found, 39 met the inclusion criteria for the systematic review. The interventions included in this review were classified into six categories (physical activity, ergonomics, psychological, environmental, multicomponent intervention, and others). The meta-analysis from 31 studies showed that the pooled effect of included interventions on SWB was significantly positive (standardized mean difference (SMD) = 0.51; standard error (SE) = 0.10). A funnel plot showed there were extremely large or small SMDs, and Egger's test was significant. Thus, we conducted sensitivity analysis, excluding these extreme SMDs, and confirmed that the estimated pooled effect was also significantly positive. Subgroup analyses for separate types of interventions showed the effects of psychological interventions (e.g., mindfulness, cognitive behavioral based approach, and other psychological interventions) were also significantly positive. Conclusion: The current study revealed the effectiveness of interventions for increasing SWB. Specifically, psychological interventions (e.g., mindfulness, cognitive behavioral based approach, and other psychological interventions) may be useful for improving SWB. (shrink)

AimTo examine the association of body mass index (BMI) [kg/m2] and its classifications (underweight [BMI < 18.5], normal [18.5 ≤ BMI < 25], overweight [25 ≤ BMI < 30], and obese [BMI ≥ 30]) with brain structure in individuals with a wide range of BMI group.Materials and methodsThe participants included 382 right-handed individuals (mean age: 46.9 ± 14.3 years, 142 men and 240 women). The intelligence quotient was assessed using the Japanese Adult Reading Test. Voxel-based morphometry (VBM) and diffusion tensor (...) imaging (DTI) were performed to analyze the association of BMI and its classifications with gray and white matter structures, respectively.ResultsAccording to VBM, BMI was significantly and negatively correlated with the bilateral cerebellum exterior volumes. In group comparisons, the right cerebellum exterior volume was significantly lower in the overweight or obese group than in the underweight or normal group, while the bilateral cuneus and calcarine cortex, left cuneus, and left precuneus volume was significantly lower in the underweight group than in the non-underweight group. Sex-related stratification analyses for VBM revealed that BMI was significantly and negatively correlated with the bilateral cerebellum exterior volumes only in women. In group comparisons, the left cerebellum exterior volume was significantly lower in obese women than in non-obese women. The left thalamus proper and the right cerebellum exterior volumes were significantly lower in overweight or obese group than in underweight or normal group in men and women, respectively. The bilateral cuneus and calcarine cortex, left cuneus and carcarine cortex, and bilateral cuneus volume was significantly lower in underweight men than in non-underweight men. In contrast, there were no notable findings on DTI.ConclusionOur results suggest association of continuous BMI, being overweight or obese, and being underweight with decreased gray matter volume in individuals with a wide range of BMI group. Furthermore, sex-related differences are seen in the association of BMI and its classifications with regional gray matter volume reductions. Abnormally high or low BMIs may have a negative influence on regional gray matter volumes. (shrink)

This article elaborates on foundational issues in the social sciences and their impact on the contemporary theory of belief revision. Recent work in the foundations of economics has focused on the role external social norms play in choice. Amartya Sen has argued in [Sen93] that the traditional rationalizability approach used in the theory of rational choice has serious problems accommodating the role of social norms. Sen's more recent work [Sen96, Sen97] proposes how one might represent social norms in the theory (...) of choice, and in a very recent article [BS07] Walter Bossert and Kotaro Suzumura develop Sen's proposal, offering an extension of the classical theory of choice that is capable of dealing with social norms. The first part of this article offers an alternative functional characterization of the extended notion of rationality employed by Bossert and Suzumura in [BS07]. This characterization, unlike the one offered in [BS07], represents a norm-sensitive notion of rationality in terms of a pure functional constraint unmediated by a notion of revealed preference (something that is crucial for the application developed in the second part of this article). This functional characterization is formulated for general domains (as is Bossert and Suzumura's characterization) and is therefore empirically more applicable than usual characterizations of rationality. Interestingly, the functional constraint we propose is a variant of a condition first entertained in [AGM85] by Carlos Alchourrón, Peter Gärdenfors and David Makinson in the area of belief change. The second part of this article applies the theory developed in the first part to the realm of belief change. We first point out that social norms can be invoked to concoct counterexamples against some postulates of belief change (like postulate (*7)) that are necessary for belief change to be relational. These examples constitute the epistemological counterpart of Sen's counterexamples against condition α in rational choice (as a matter of fact, Rott has showed in [Rot01] that condition and postulate (*7) are mutually mappable). These examples are variants of examples Rott has recently presented in [Rot04]. One of our main goals in this article consists in applying the theory developed in the first part to develop a theory of norm-inclusive belief change that circumvents the counterexamples. We offer a new axiomatization for belief change and we furnish correspondence results relating constraints of rational choice to postulates of belief change. (shrink)

in Intergenerational Equity and Sustainability, edited by John Roemer and Kotaro Suzumura, (Palgrave Publishers Ltd., forthcoming 2007), ch.11.

Public-policy choices frequently have to be carried out in the presence of incommensurabilities. These incommensurabilities may manifest themselves in the form of incompleteness—that is, some of the options under consideration are not comparable by a decision maker. As a consequence, it may be impossible to select policies that are at least as good as all competing proposals. When faced with incommensurabilities of this nature, transitivity can be considered too demanding a requirement. An attractive weakening of transitivity consists of a property (...) that Kotaro Suzumura (Economica, 43:381–390, 1976) introduced under the label of consistency. Suzumura consistency postulates that goodness cycles with at least one instance of betterness are to be avoided thus strengthening the well-known acyclicity condition that precludes the existence of betterness cycles. The property is compared to alternative weakenings of transitivity, and it is shown that it has numerous advantages over other contenders. For instance, Suzumura consistency is precisely what is needed to avoid a money pump. The issue of rational choice in the context of public decision-making is discussed in order to provide an illustration of the usefulness of Suzumura consistency. (shrink)

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)

We examine the impact of Suzumura’s (Economica 43:381–390, 1976) consistency property when applied in the context of collective choice rules that are independent of irrelevant alternatives, neutral, and monotonic. An earlier contribution by Blau and Deb (Econometrica 45:871–879, 1977) establishes the existence of a vetoer if the collective relation is required to be complete and acyclical. The purpose of this paper is to explore the possibilities that result if completeness and acyclicity are dropped and Suzumura consistency is imposed (...) instead. A conceptually similar but logically independent version of the combined axiom that requires the collective decision mechanism to be independent, neutral, and monotonic is employed. In the case of a finite population, we obtain an alternative impossibility theorem if a collective choice rule is assumed to be non-degenerate and a modified no veto requirement is imposed instead of Blau and Deb’s (1977) condition. If the population is countably infinite, the impossibility can be avoided but it resurfaces if our new no veto property is extended to a coalitional variant. (shrink)

This study investigates Suzumura consistency as a condition for the rationality of social preferences. A preference is said to be Suzumura-consistent when all preference cycles include only indifference relations. This condition is equivalent to transitivity in the presence of completeness, but, in general, it is substantially weaker than transitivity when preference is incomplete. Notably, Suzumura consistency is especially significant for a preference because it is necessary and sufficient for the existence of an ordering (transitive and complete preference) (...) that is compatible with the original preference. This coherency property can be regarded as a requirement for potential rationality. In this study, we examine the implications of shifting from actual rationality to potential rationality in collective decision-making. We introduce the concept of an alternative-dependent coherent collection in order to obtain a representation of a class of Suzumura-consistent collective choice rules that satisfy the axioms imposed in Arrow’s impossibility theorem. This demonstrates that the power structure to determine social choice can be alternative-dependent. (shrink)

We examine the range of anonymity that is compatible with a Paretian social welfare relation (SWR) on infinite utility streams. Three alternative coherence properties of an SWR are considered, namely, acyclicity, quasi-transitivity, and Suzumura consistency. For each case, we show that a necessary and sufficient condition for a set of permutations to be the set of permissible permutations of some Paretian SWR is given by the cyclicity of permutations and a weakening of group structure. Further, for each case of (...) coherence property, we show that the extended Pareto rule is the least element of the class of anonymous Paretian SWRs. (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'.

Jeanne Fichtner-Egloff analysiert die Epoche um 1900 in Japan und zeigt, dass sie als Übergang in ein neues Selbstverständnis in der Kunst zu verstehen ist. Mit den um 1910 herausgegebenen Schriften des Bildhauers und Schriftstellers Takamura Kōtarōs wurde zum ersten Mal die uneingeschränkte Ausdrucksfreiheit der subjektiven Empfindung eines Künstlers propagiert. Mit diesem Verständnis schien plötzlich ein allgemein gültiges Konzept von Kunst als autonome Schöpfung zu existieren, das sich an die Ideen der fauvistischen Künstler in Frankreich anlehnte. Gleichzeitig entstanden in den (...) Städten erste private Galerien und Messen und es bildeten sich eigenständige Künstlergruppen, die selbst Ausstellungen organisierten, ohne sich offiziellen Begutachtern zu unterwerfen. Diese Entwicklung erzeugte ein interessantes Spannungsfeld zwischen traditionellen Kunstauffassungen und neu rezipiertem westlichen Gedankenguts. (shrink)

We characterize the existence of semicontinuous weak utilities in a general framework, where the axioms of transitivity and acyclicity are relaxed to that of consistency in the sense of Suzumura (Economica 43:381–390, 1976). This kind of representations allow us to transfer the problem of the existence of the ${{\mathcal{G}}{\mathcal{O}}{\mathcal{C}}{\mathcal{H}}{\mathcal{A}}}$ set of a binary relation to the easier problem of getting maxima of a real function. Finally, we show that the maxima of these representations correspond to the different levels of (...) satiation that each of individual has (an individual reaches his or her level of satiation when an increase of consuming an alternative product/service brings no increase in utility). (shrink)

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)

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)