Semicontinuous Representability of Homothetic Interval Orders by Means of Two Homogeneous Functionals

It is well known that interval orders are particularly interesting in decision theory, since they are reflexive, complete and nontransitive binary relations which may be fully represented by means of two real-valued functions. In this paper, we discuss the existence of a pair of nonnegative, positively homogeneous and semicontinuous real-valued functionals representing an interval order on a real cone in a topological vector space. We recover as a particular case a result concerning the existence of a nonnegative, positively homogeneous and continuous utility functional for a complete preorder on a real cone in a topological vector space.     

Continuous Utility Functions Through Scales

We present here a direct elementary construction of continuous utility functions on perfectly separable totally preordered sets that does not make use of the well-known Debreu’s open gap lemma. This new construction leans on the concept of a separating countable decreasing scale. Starting from a perfectly separable totally ordered structure, we give an explicit construction of a separating countable decreasing scale, from which we show how to get a continuous utility map.      

Micro-mobilization into Armed Groups: Ideological, Instrumental and Solidaristic Paths

Based on biographical materials of armed militants of the Provisional Irish Republican Army and Red Brigades, this article analyses variation within the micromobilization that leads to armed groups. Three general paths are singled out: the ideological path, the instrumental path and the solidaristic path. Each of these is characterized by complex interactions between the individual motivations for involvement (micro-level), the networks that facilitate the recruitment process (meso-level), and the effects of repression on individuals (macro-level). We discuss the discoveries we have made and conclude by describing the advantages of our approach.     

Existence of homogeneous representations of interval orders on a cone in a topological vector space

Necessary and sufficient conditions are presented for the existence of a pair <u,v> of positively homogeneous of degree one real functions representing an interval order on a real cone K in a topological vector space E (in the sense that, for every x,yK, xy if and only if u(x)v(y)), with u lower semicontinuous, v upper semicontinuous, and u and v utility functions for two complete preorders intimately connected with . We conclude presenting a new approach to get such kind of representations, based on the concept of a biorder.This research has been supported by the Integrated Action of Research HI2000-0116 (Spain-Italy). Also, the work of coauthors Candeal and Induráin has been partially supported by the research project PB98-551 Estructuras ordenadas y aplicaciones (M.E.C. Spain, December 1999).     

Armed activism as the enactment of a collective identity: the case of the Provisional IRA between 1969 and 1972

This paper argues that micro-mobilization into armed activism is strongly motivated by the enactment of an identity that people already have prior to their mobilization as a way to strongly assert and emphasize individual agency in the face of major changes in the political context. Empirically, it advocates that those who joined the Provisional IRA between 1969 and 1972 did so in order to respond to a need for action by a northern nationalist community that stemmed from a perceived, alleged or actual, sense of second-class citizenship. We suggest that the importance of identity rather than ideology can also help us to explain why IRA members and former members overwhelmingly accepted the compromise peace settlement of the 1990s despite the fact that core ideological goals had not been realized. We conclude by suggesting avenues for future research outside the Irish context.     

Topologies for semicontinuous Richter–Peleg multi-utilities

Theory and Decision - The present paper gives a topological solution to representability problems related to multi-utility, in the field of Decision Theory. Necessary and sufficient topologies for...