Group betweenness and co-betweenness: Inter-related notions of coalition centrality

Vertex betweenness centrality is a metric that seeks to quantify a sense of the importance of a vertex in a network in terms of its ‘control’ on the flow of information along geodesic paths throughout the network. Two natural ways to extend vertex betweenness centrality to sets of vertices are (i) in terms of geodesic paths that pass through at least one of the vertices in the set, and (ii) in terms of geodesic paths that pass through all vertices in the set. The former was introduced by Everett and Borgatti [Everett, M., Borgatti, S., 1999. The centrality of groups and classes. Journal of Mathematical Sociology 23 (3), 181–201], and called group betweenness centrality. The latter, which we call co-betweenness centrality here, has not been considered formally in the literature until now, to the best of our knowledge. In this paper, we show that these two notions of centrality are in fact intimately related and, furthermore, that this relationship may be exploited to obtain deeper insight into both. In particular, we provide an expansion for group betweenness in terms of increasingly higher orders of co-betweenness, in a manner analogous to the Taylor series expansion of a mathematical function in calculus. We then demonstrate the utility of this expansion by using it to construct analytic lower and upper bounds for group betweenness that involve only simple combinations of (i) the betweenness of individual vertices in the group, and (ii) the co-betweenness of pairs of these vertices. Accordingly, we argue that the latter quantity, i.e., pairwise co-betweenness, is itself a fundamental quantity of some independent interest, and we present a computationally efficient algorithm for its calculation, which extends the algorithm of Brandes [Brandes, U., 2001. A faster algorithm for betweenness centrality. Journal of Mathematical Sociology 25, 163] in a natural manner. Applications are provided throughout, using a handful of different communication networks, which serve to illustrate the way in which our mathematical contributions allow for insight to be gained into the interaction of network structure, coalitions, and information flow in social networks.     

A framework for the comparison of maximum pseudo-likelihood and maximum likelihood estimation of exponential family random graph models

The statistical modeling of social network data is difficult due to the complex dependence structure of the tie variables. Statistical exponential families of distributions provide a flexible way to model such dependence. They enable the statistical characteristics of the network to be encapsulated within an exponential family random graph (ERG) model. For a long time, however, likelihood-based estimation was only feasible for ERG models assuming dyad independence. For more realistic and complex models inference has been based on the pseudo-likelihood. Recent advances in computational methods have made likelihood-based inference practical, and comparison of the different estimators possible.     

In search of career satisfaction: African-American public relations practitioners, pigeonholing, and the workplace

The goals of the research were to explore African-American practitioners’ satisfaction with public relations as a career and to examine their perceptions of tokenism and pigeonholing in the workplace. Three key themes emerged from the research: career entry and social support in public relations; encounters with everyday racism; and pigeonholing in public relations. For the majority of 12 African-American practitioners interviewed, they have experienced discrimination in their careers and in public relations, yet the practitioners did not see themselves as pigeonholed in their roles or positions. The complete study can be requested from the author.     

The meaning of frailty according to Dutch older frail and non-frail persons

Frailty is a term often used by researchers and clinicians to describe a state in which older persons are at risk for adverse outcomes such as falls, disability, institutionalization and mortality. However, no study so far examined what frailty means to older persons. Therefore the aim of this study was to describe the meaning that older community-dwelling persons attach to frailty. Twenty-five semi-structured interviews were conducted. The interviews were analyzed using the grounded theory method. Frailty was described as being in poor health, having walking difficulties, feeling down, being anxious, having few social contacts and not being able to do the things one likes to do. Men described in more detail the physical dimension whereas women elaborated in more depth on the psychological and social component. Existing definitions of frailty should be adjusted to better reflect the meaning of frailty for older persons.     

Communication in assisted living

This study of communication in an Assisted Living Facility (ALF) focuses on staff's interpretive frameworks and situational tactics for managing elderly residents. It is based on interviews with staff and residents in an ALF together with ethnographic fieldwork. As in other quasi-total institutions, staff members engage in control as well as care, monitoring residents for compliance with rules and directives. Residents, aware of the threat of being moved to a nursing home, also monitor their own behavior and cognition in comparison to other residents. Other communication issues include the infantilization of the elderly by staff, and the race, class, and ethnic prejudices of residents.     

The Impact of Flexible Working Arrangements on Work–life Conflict and Work Pressure in Ireland

Recent rapid economic growth in Ireland has been accompanied by a strong surge in the number of women in employment, and this has led to a significant increase in the proportion of dual‐earner families. These changes have brought the issue of reconciliation between work and care commitments to the fore. Flexible working arrangements in firms have been identified as one important means of balancing work and other commitments. In this article we investigate the relationship between four flexible working arrangements; flexitime, part‐time hours, working from home and job sharing, and two key employee outcomes; work pressure and work–life conflict, using data from the first national survey of employees in Ireland in 2003. Our results show that while part‐time work and flexitime tend to reduce work pressure and work–life conflict, working from home is associated with greater levels of both work pressure and work–life conflict. We conclude that it is important to distinguish between flexible working arrangements to discover their potential for reducing work pressure and work–life conflict.     

Living on the margin: disabled Iranians in Belgian society

This paper explores the antecedents, experiences and consequences of marginalization as reported and dealt with by disabled Iranian immigrants in Belgium. This work extends the work of Gallie and colleagues and Siegrist demonstrating that the forces of marginalization applicable to all immigrants are particularly pertinent to disabled immigrants. The research is based on 26 in‐depth, face‐to‐face interviews, focus groups, interviews with government officials and immigration experts, ethnographic work and official government statistics. The findings detail how the combined forces of history, context and reasons for immigration; isolation, vulnerability and perceived loss of control; religion and rejection; lack of reciprocity in social exchanges; problems in obtaining jobs; and difficulties in negotiating an entry into Belgian society combine to sustain marginizalation. As a consequence, disabled immigrants in this group are generally excluded from society and discriminated against in terms of citizenship, education, jobs and general acceptance.     

Prevalence,people and processes: a consideration of the implications of Lord Laming's progress report on the protection of children in England

Media coverage of the death of Baby P revived national concerns about the standard of child safeguarding practice in England following the implementation of widespread structural changes in response to the Victoria Climbié Inquiry chaired by Lord Laming in 2003. This paper discusses the recommendations of Lord Laming's recent Progress Report. It questions whether the scale of the challenge in improving child protection is fully recognised and considers briefly the culture of social care in the UK and the barriers to effective reform. Copyright © 2009 John Wiley & Sons, Ltd.     

Digital Inequality and Place: The Effects of Technological Diffusion on Internet Proficiency and Usage across Rural,Suburban, and Urban Counties*

Recently researchers have made efforts to reconceptualize digital inequality into discrete levels. These levels reflect access to and diffusion of technologies, proficiency in Internet usage, and propensity to take advantage of the opportunities afforded by information and communication technologies for assistance in daily life. We assess the utility of this approach for studying digital inequality across rural, suburban, and urban counties. Based on data from a 2005 nationally representative random sample telephone survey of 2,185 adults, the results provide mixed support for using this approach to studying digital inequality. In particular, we find that rural residents use Internet technologies less for assistance in helping with economics and other daily activities when compared with individuals from suburban and urban areas; however, our results suggest that this relationship is the product of the slow diffusion of advanced technologies to rural areas. The implications of these findings for understanding this under‐theorized form of inequality are discussed, and we make contributions to this literature through empirically addressing issues of digital capital.     

DISCRIMINATION, WOMEN, AND WORK: Processes and Variations by Race and Class

Research on gender and workplace stratification has made clear that persistent employment, wage, and mobility gaps exist, and that discrimination at organizational and interactional levels is playing a role. Few studies, however, have been able to directly capture processes involved. In this article, we draw on unique qualitative and quantitative data pertaining to verified cases of workplace sex and race discrimination (1988 to 2003), and analyze the discriminatory experiences of African-American and white women across various occupational statuses. Notable are high levels of discriminatory firing for both groups, but higher instances of race-based promotional discrimination for black women—a pattern partially linked to their disparate concentration in sex-segregated workplaces and in positions of lower occupational prestige. Our qualitative immersion into case materials reveals influential mechanisms and employer justifications, unique manifestations of differential treatment on the job, and the use of "soft skill" criteria in gatekeeper decision making. We conclude by discussing important dimensions of workplace discrimination for women, variations by social class and race status, and how complexities of status matter for what women experience and gatekeeper behavior.