Characterization of social choice sets in terms of individuals' maximal sets: The fixed agenda framework

In this paper we analyze the explicit representation of fixed agenda social choice correspondences under different rationality assumptions (independence, Pareto optimality, etc.). It is well known that, under some of these assumptions, the existence of dictators, oligarchies or individuals with veto power can be proven ([6] and [10]); but only a partial characterization of the social choice set is obtained. We establish a relationship between the social choice set and the individuals' maximal sets, which explicitly describes a fixed agenda social choice correspondence that satisfies these rationality assumptions. Received: 30 December 1997/Accepted: 20 December 1999     

Choice Functions: Rationality re-Examined

On analyzing the problem that arises whenever the set of maximal elements is large, and a selection is then required (see Peris & Subiza 1998), we realize that logical ways of selecting among maximals violate the classical notion and axioms of rationality. We arrive at the same conclusion if we analyze solutions to the problem of choosing from a tournament (where maximal elements do not necessarily exist). So, in our opinion the notion of rationality must be discussed, not only in the traditional sense of external conditions (Sen 1993), but in terms of the internal information provided by the binary relation.     

What Is Different about the Profile of the Social Entrepreneur?

In recent years, the term social entrepreneur has become increasingly common in academic and business circles. Social entrepreneurs engage in a variety of activities, but always with the intention of solving social problems. Social entrepreneurs are not merely people who perform acts of charity; they have an evident desire to improve social well‐being and develop projects with long‐term vision. The creation of sustainable social value is a key characteristic that differentiates them from well‐meaning individuals who simply engage in charitable works. There are, however, significant gaps in our understanding of social entrepreneurs and few empirical studies on the subject. This present study attempts to identify the characteristics of more socially oriented entrepreneurs, using sociodemographic variables and the theory of universal values toward work. Analysis of a sample of approximately 400 people shows that more than half of entrepreneurial orientation can be explained through the possession of the values of self‐enhancement (with an inverse relationship in this case), self‐transcendence, and conservation. The theory of universal values has proved extraordinarily useful for studying the characteristics of social entrepreneurs.     

Veto in fixed agenda social choice correspondences

In this paper we analyze the relationship between social decision functions (SDF) and fixed agenda social choice correspondences (fixed agenda SCC), satisfying some rationality conditions (such as Pareto, Independence, Monotonicity, Neutrality or Anonimity), with the aim of translating known results on the existence of individuals with veto power into the fixed agenda framework (e.g., Blair and Pollak [2], Blau and Deb [3], …). In order to do this, a new independence condition (which we call Pseudo-Independence), as well as a notion of veto power, are introduced in the context of fixed agenda SCC. The conclusion is that, by fixing the agenda, under Independence and Pareto assumptions, the existence of individuals with veto power cannot be avoided. Received: 6 November 1995 / Accepted: 9 September 1997     

Condorcet choice functions and maximal elements

Choice functions on tournaments always select the maximal element (Condorcet winner), provided they exist, but this property does not hold in the more general case of weak tournaments. In this paper we analyze the relationship between the usual choice functions and the set of maximal elements in weak tournaments. We introduce choice functions selecting maximal elements, whenever they exist. Moreover, we compare these choice functions with those that already exist in the literature.Thanks are due to José Alcalde, J.V. Llinares and M.C. Sánchez, for helpful comments. The comments and suggestions of a referee’s report have improved the work; we are most grateful to her/him. Financial support from the Spanish DGICYT, under project BEC2001-0781, Fundación Séneca (PI74/00826/FS/01) and from the IVIE is acknowledged.     

Condorcet choice correspondences for weak tournaments

Tournaments are complete and asymmetric binary relations. This type of binary relation rules out the possibility of ties or indifferences which are quite common in other contexts. In this work we generalize, from a normative point of view, some important tournament solutions to the context in which ties are possible. Received: 12 November 1996/Accepted: 4 November 1997