Modeling large electorates with Fourier series, with applications to Nash equilibria in proximity and directional models of spatial competition

 In this paper we introduce harmonic analysis (Fourier series) as a tool for characterizing the existence of Nash equilibria in two-dimensional spatial majority rule voting games with large electorates. We apply our methods both to traditional proximity models and to directional models. In the latter voters exhibit preferences over directions rather than over alternatives, per se. A directional equilibrium can be characterized as a Condorcet direction, in analogy to the Condorcet (majority) winner in the usual voting models, i.e., a direction which is preferred by a majority to (or at least is not beaten by) any other direction. We provide a parallel treatment of the total median condition for equilibrium under proximity voting and equilibrium conditions for directional voting that shows that the former result is in terms of a strict equality (a knife-edge result very unlikely to hold) while the latter is in terms of an inequality which is relatively easy to satisfy. For the Matthews [3] directional model and a variant of the Rabinowitz and Macdonald [7] directional model, we present a sufficiency condition for the existence of a Condorcet directional vector in terms of the odd-numbered components of the Fourier series representing the density distribution of the voter points. We interpret our theoretical results by looking at real-world voter distributions and direction fields among voter points derived from U.S. and Norwegian survey data. Received: 7 July 1995 / Accepted: 14 May 1996     

Workshop to Orient Students to Career Planning Services

This article describes a 1-hour workshop designed to orient students to a career resource center and assist them with career decision making.     

A sociology of hackers

Illicit computer intruders, or hackers, are often thought of as pathological individuals rather than as members of a community. However, hackers exist within social groups that provide expertise, support, training, journals and conferences. This article outlines this community to establish the nature of hacking within ‘information societies’. To delineate a ‘sociology of hackers’, an introduction is provided to the nature of computer–mediated communication and the act of computer intrusion, the hack. Following this the hacking community is explored in three sections. First, a profile of the number of hackers and hacks is provided by exploring available demographics. Second, an outline of its culture is provided through a discussion of six different aspects of the hacking community. The six aspects are technology, secrecy, anonymity, membership fluidity, male dominance and motivations. Third, an exploration of the community's construction of a boundary, albeit fluid, between itself and its other, the computer security industry, is provided. This boundary is constructed through metaphors whose central role is to establish the ethical nature of hacking. Finally, a conclusion that rejects any pathologisation of hackers is offered.     

An Evaluation of a Child Guidance Clinic

An attempt is made to evaluate the effectiveness of a child guidance clinic. The outcome of the clinic's intervention was found to vary according to the nature of the presenting problem and the social class of the client. The categories of problems where treatment was ineffective are discussed in detail.     

Random regression models for human immunodeficiency virus ribonucleic acid data subject to left censoring and informative drop-outs

Objectives in many longitudinal studies of individuals infected with the human immunodeficiency virus (HIV) include the estimation of population average trajectories of HIV ribonucleic acid (RNA) over time and tests for differences in trajectory across subgroups. Special features that are often inherent in the underlying data include a tendency for some HIV RNA levels to be below an assay detection limit, and for individuals with high initial levels or high ranges of change to drop out of the study early because of illness or death. We develop a likelihood for the observed data that incorporates both of these features. Informative drop-outs are handled by means of an approach previously published by Schluchter. Using data from the HIV Epidemiology Research Study, we implement a maximum likelihood procedure to estimate initial HIV RNA levels and slopes within a population, compare these parameters across subgroups of HIV-infected women and illustrate the importance of appropriate treatment of left censoring and informative drop-outs. We also assess model assumptions and consider the prediction of random intercepts and slopes in this setting. The results suggest that marked bias in estimates of fixed effects, variance components and standard errors in the analysis of HIV RNA data might be avoided by the use of methods like those illustrated.     

Production mondialisée et progrès social: le cas du textile et de l'habillement

La fragmentation de la production au sein de réseaux mondiaux n'obéit pas seulement à l'avantage comparatif, mais aussi aux décisions de localisation des entreprises dominantes en fonction de la capacité de négociation des producteurs locaux et du rôle qu'elles leur assignent dans la chaîne de production. Les auteurs examinent les conséquences de cette spécialisation dans le textile et l'habillement, pour vingt‐six pays où l'offre de main‐d'?uvre est abondante, sur la période 1990–2007. L'étude économétrique montre que le secteur ne tire pas toujours bénéfice de l'intégration commerciale: on observe plutôt une association négative entre spécialisation verticale et salaires réels.     

‘I’m not really sure but I hope it’s better’: early thoughts of parents and carers in a regional trial site for the Australian National Disability Insurance Scheme

The National Disability Insurance Scheme (NDIS) is one of the most significant initiatives in Australian social policy history. Its complexity has been compounded by a fast-paced introduction and ongoing refinement throughout the initial trial phase. Parents and carers of very young disabled children face particular challenges accessing and navigating NDIS systems. This article presents findings from a mixed-method pilot study examining the perspectives of parents and carers of disabled children in one NDIS trial site – the Hunter Region of New South Wales. The research highlights a number of policy assumptions potentially impacting on NDIS take up for young disabled children and their families in regional contexts. Based on research findings a number of policy suggestions and improvements for disabled children and their families entering the NDIS and other individualised funding schemes are outlined.     

Grading Gems: Appraising the Quality of Research for Social Work and Social Care

The impetus towards basing practice and policy decisions moreexplicitly on sound research requires tools to facilitate thesystematic appraisal of the quality of research encompassinga diverse range of methods and designs. Five exemplar toolswere developed and assessed in terms of their usefulness inselecting studies for inclusion in a systematic review. Thewidely used ‘hierarchy of evidence’ was adaptedand used to appraise internal validity. Four tools were thendeveloped to appraise the external validity dimensions of generalizability(two scales) and methods of data collection (two scales). Methodsof combining the scores generated by each tool were explored.Qualitative and quantitative studies were appraised, not separatedinto two spheres but by using complementary tools developedto appraise different aspects of rigour. There was a high levelof agreement between researchers in applying the tools to twenty-twostudies on decision making by professionals about the long-termcare of older people. The scales for internal validity and generalizabilitydiscriminated between the qualities of studies appropriately.The two tools to appraise data collection gave diverse results.Excluding studies that scored in the lowest category on anyscale appeared to be the scoring system that was most justifiable.This approach is presented to stimulate debate about the practicalapplication of the evidence-based initiative to social workand social care. This study may assist in developing clearerdefinitions and common language about appraising rigour thatshould further the process of selecting robust research forsynthesis to inform practice and policy decisions.