We provide the first necessary and sufficient conditions in the literature for the existence of maximal elements in a non-binary choice framework. As an application, the characterization of the existence of maximal elements for acyclic binary relations obtained in Rodŕıguez-Palmero and Garćıa-Lapresta, 2002, Mathematical Social Sciences 43, 55-60, is deduced as a Corollary. Further characteriza...

Social choice theory argues mathematical models and their logical consequences for group decision making based on individuals’ preference orderings axiomatically. The most basic results have been proved in this field are two impossibility results for group decision making. Arrow’s general (im)possibility theorem for preference aggregation procedures, i.e., there is no nondictatorial social welf...

This paper provides a brief introduction to the use and usefulness of Suzumura consistency, a coherence requirement for binary relations that weakens transitivity. The property is introduced by Suzumura (1976b) in the context of collective choice but, as demonstrated in some recent contributions, its applicability reaches beyond the boundaries of social-choice theory. In addition to a summary o...

Research on conjoint analysis/preference aggregation/social choice aggregation is performed by more than forty years by various communities. However, many proposed mathematical models understand preferences as irreflexive, transitive and statical relations while there is human psychology research work questioning these properties as being not enough motivated. This works propose to position the...

A doctorate in one—albeit particularly prestigious—of the institutes of the USSR Academy of Sciences is an unlikely background for a democratic theorist. Yet, it is with this background that Andranik Tangian, now a resident of Germany, has taken up the task of writing a comprehensive treatise on the development of democratic thinking from its early beginnings ca. 500 BC to the modern days. Tang...

Throughout this paper, our  main idea is to analyze the Arrovian approach in a fuzzy context, paying attention to different extensions of the classical Arrow's model arising in mathematical Social Choice to aggregate preferences that the agents define on a set of alternatives. There is a wide set of extensions. Some of them give rise to an impossibility theorem as in the Arrovian classical  mod...

Exposure to news, opinion, and civic information increasingly occurs through social media. How do these online networks influence exposure to perspectives that cut across ideological lines? Using deidentified data, we examined how 10.1 million U.S. Facebook users interact with socially shared news. We directly measured ideological homophily in friend networks and examined the extent to which he...