We use a simple graphical approach to represent Social Welfare Functions that satisfy Independence of Irrelevant Alternatives
and Anonymity. This approach allows us to provide simple and illustrative proofs of May's Theorem, of variants of classic
impossibility results, and of a recent result on the robustness of Majority Rule due to Maskin (1995). In each case, geometry
provides new insights on the working and interplay of the axioms, and suggests new results including a new characterization
of the entire class of Majority Rule SWFs, a strengthening of May's Theorem, and a new version of Maskin's Theorem.
Received: 31 July 1999/Accepted: 27 March 2001 相似文献
We study the problem of ranking sets of options in terms of freedom of choice. We propose a framework in which both the diversity of the options and the preferences of the agent over the options do play a role. We formulate some axioms that reflect these two aspects of freedom and we study their logical implications. Two different criteria for ranking sets are characterized, which generalize some of the rankings proposed so far in the literature. 相似文献
An analysis of 120 corporate websites from Denmark, France, Germany, Norway, Singapore, Spain, the United Kingdom and the United States reveals, for the first time, international results about the implementation and use of virtual press rooms. This article shows the importance that large international companies attribute to Web-based media centers to achieve organizational objectives and to meet journalists’ demands for information and audiovisual resources. The study also shows, however, that most press rooms are far from being complete, efficient, easy-to-use, reliable and updated on a daily basis. In fact, there is not a single country from those analyzed that consistently stands out from the rest. In most of them, good results in certain areas coexist with significant shortcomings in others, resulting in some cases in poor press rooms that may not achieve the desired public relations objectives. 相似文献
Oja (1983) examined various ways of measuring location, scatter, skewness, and kurtosis for multivariate distributions. Among other measures of location, he introduced a generalised median known in this paper under the name of the Oja median. In our study of the existence of that median, we show that Oja's definition can only be applied to distributions having a mean. In dimension d θ 2, we establish that the usual method of extension breaks down, which raises the question of the validity of the concept as a notion of median. Two fundamental theoretical properties of that median are also considered: uniqueness and consistency. 相似文献
Puerto Rican migration to the US has been a more or less continuous process since 1917. The perspective of viewing return migration as a circulation process suggests that there are entries, exits, and reintergration into the metropolitan labor market. This study explores the circulatory movements of Puerto Rican families, events that influence the adaptation process when returning to Puerto Rico, and cultural identity aspects. Data collected by means of 2 research instruments that were administered to the respondents simultaneously were used: 1) a life history matrix and 2) an open-ended questionnaire. These interviews outlined the principal problems of adaptation as mentioned by the circulating migrants. The most difficult problems to adjust to were economic and employment (58%), followed by social acceptance (23%), education (17%), and language (15%). Transportation, medical services, and recreational facilities were also problems mentioned as being significant. It is expected that a great majority of migrant laborers will go to live in immigrant residential locations in large US cities. It is also expected that these migrants will meet with certain value conflicts by living in urban ghettos. These families will have serious difficulties finding economic stability and will possibly consider migrating once again as an alternative to their social reality. This study illustrates that: 1) the migrants return in family groups; 2) they face discriminatory problems in employment agencies and schools; 3) they look forward to a formal education as a means of social mobility; 4) they identify themselves with values, habits, and Puerto Rican traditions; and 5) they value the quality of life in Puerto Rico. 相似文献
This article describes organizational symbolismfrom a sociology of knowledge perspective and considersboth the theoretical and extra-theoretical bases of thesymbolic approach. It illustrates the distinctive principles of the symbolic approach withrespect to other methods used in the study oforganizations, the concepts on which it is based, andthe organizational issues on which it has shedsignificant light. Symbolist studies of organizations haverefocused scholarly attention on the multidisciplinaryunderstanding of the logos, ethos, and pathos oforganizational life. They have done so by stressing the production of knowledge tout court, rather thanconcerning themselves with the applicability of theorganizational knowledge acquired by this approach formanagerial purposes. Organizational symbolism is described in the article as a fluctuatingand emerging social construction whose growth and spreadhas been fostered by support within academia. 相似文献
Skinner (1957) differentiated the roles of the speaker and the listener in a verbal encounter. Although not extensively emphasized, Skinner suggested an individual often behaves verbally even when responding as a listener. Children diagnosed with autism spectrum disorders (ASD) often display the absence of important, and basic verbal repertoires that limit their ability to engage in a variety of social skills or problem-solving skills. Joint control suggests that multiply controlled verbal responding involves functional control of two 2 or more stimuli or verbal operants. This systematic literature review provides a summary of publications specifying the relation and implications of the analysis of joint control and joint control training in the acquisition of multiply controlled, non-speaker behaviors (e.g., selection-based behavior; , sequencing behavior). The synthesis suggests that joint control training presents as a promising analytic tool in guiding interventions to teach complex, multiply controlled verbal and non-verbal repertoires to children diagnosed with autism ASD and/or other developmental disabilities. Recommendations for future research in joint control, as well as the implementation of joint control training, are provided.
Portmanteau tests are typically used to test serial independence even if, by construction, they are generally powerful only in presence of pairwise dependence between lagged variables. In this article, we present a simple statistic defining a new serial independence test, which is able to detect more general forms of dependence. In particular, differently from the Portmanteau tests, the resulting test is powerful also under a dependent process characterized by pairwise independence. A diagram, based on p-values from the proposed test, is introduced to investigate serial dependence. Finally, the effectiveness of the proposal is evaluated in a simulation study and with an application on financial data. Both show that the new test, used in synergy with the existing ones, helps in the identification of the true data-generating process. Supplementary materials for this article are available online. 相似文献
The literature on preferences for redistribution has paid little attention to the effect of social mobility on the demand for redistribution and no systematic test of the hypotheses connecting social mobility and preferences for redistribution has yet been done to date. We use the diagonal reference model to estimate the effect of origin and destination classes on preferences for redistribution in a large sample of European countries using data from the European Social Survey. Our findings are consistent with the logic of acculturation in the sense that newcomers tend to adapt their views to those of the destination class at early stages and that upward and downward mobility do not have distinctive effects on the formation of political preferences. However, even though social origins seem to have a limited impact on preferences for redistribution, the evidence does not support the hypothesis that mobile and non‐mobile individuals are alike. We also find that the effect of social origin on preferences varies largely across countries. The empirical evidence leads to the conclusion that the effect of social origin on preferences for redistribution increases in contexts of strong familism. 相似文献