Simplex Mixed‐Effects Models for Longitudinal Proportional Data

Abstract. Continuous proportional outcomes are collected from many practical studies, where responses are confined within the unit interval (0,1). Utilizing Barndorff‐Nielsen and Jørgensen's simplex distribution, we propose a new type of generalized linear mixed‐effects model for longitudinal proportional data, where the expected value of proportion is directly modelled through a logit function of fixed and random effects. We establish statistical inference along the lines of Breslow and Clayton's penalized quasi‐likelihood (PQL) and restricted maximum likelihood (REML) in the proposed model. We derive the PQL/REML using the high‐order multivariate Laplace approximation, which gives satisfactory estimation of the model parameters. The proposed model and inference are illustrated by simulation studies and a data example. The simulation studies conclude that the fourth order approximate PQL/REML performs satisfactorily. The data example shows that Aitchison's technique of the normal linear mixed model for logit‐transformed proportional outcomes is not robust against outliers.     

POM TEACHING AND RESEARCH IN THE 21st CENTURY

We offer a view of operations management in the future based on a mapping of the field's history. We discuss issues raised by this view of the future that we expect will affect those who will teach and conduct research in operations management.     

MANUFACTURING PROCESS TECHNOLOGY and SUPPORT STAFF COMPOSITION: AN EMPIRICAL VIEW OF INDUSTRY EVIDENCE

Despite the attention given to restructuring and trimming down manufacturing firms during the 198Os, little attention has been paid to the mix of skills they needed under different circumstances. We examined the patterns of employment by occupation in manufacturing industries utilizing different production technologies and the effect of establishment size on nonproduction employment. We found that a relationship exists between production technology and nonproduction employment per 100 production workers. Establishment size is found to be a moderator between nonproduction employment and production technology. Our findings imply two clear messages for managers. First, when considering major changes in production technology, managers should be aware that the supporting skills they will need from their nonproduction work force are likely to change greatly. Further, these changes involve technical and managerial workers as well as clerical and production support people. Second, they should restructure the functional or occupational mix of an organization in the context of the process technologies in place. Different process technologies require different structures.     

Southern African social movements at the 2007 Nairobi World Social Forum

How relevant is the anti‐globalization movement to the ideas and activities of social movements seeking to achieve economic justice and greater democratic accountability in southern Africa? Case study research in four southern African countries (Zimbabwe, Zambia, Malawi and Swaziland) indicates that, while aspects of the anti‐globalization approach resonate with civil society and social movement actors (for example, an emphasis on mass participation and the internationalization of campaigning), the global social justice movement frequently displays the characteristics of globalization. These include: unaccountable decision‐making; profound (yet largely unacknowledged) inequality of access to resources; and an imposed and uniform organizational form that fails to consider local conditions. The World Social Forum (WSF) held in Nairobi in January 2007 provided many southern African social movement actors with their first opportunity to participate in the global manifestation of the anti‐globalization movement. The authors interviewed social movement activists across southern Africa before and during the Nairobi WSF about their experiences of the anti‐globalization movement and the Social Forum. An assessment of the effectiveness of this participation leads to the conclusion that the WSF is severely limited in its capacity to provide an effective forum for these actors to express their grievances and aspirations. However, hosting national social forums, their precise form adapted to reflect widely varied conditions in southern African states that are affected by globalization in diverse ways, appears to provide an important new form of mobilization that draws on particular elements of anti‐globalization praxis.     

Parental access to children in care—the research messages

SUMMARY. The basic facts about access of parents to their children in care are simply stated: a significant number of children in care have parental access limited either deliberately or inadvertently, without professional or legal justification, and the result of this is that contact between parents and children withers, and may reduce to nothing. How much does this matter? How common is it? Why does it happen? These questions will be examined below. We shall see that access in care merits serious attention and highlights important issues concerning the role of the social services in the spectrum of professional support available to families with children. The article is based on a paper given in 1986 to a Family Rights Group study course on access to children in care     

The Social standing of ethnic and racial groupings*

L'article établi l'existence d'une échelle des groupes ethniques et raciales, selon leur position sociale, au Canada anglophone et francophone. Les données de l'étude étaient recueillies pendant une étude sur le prestige professionnel, utilisant une forme de question identique pour obtenir l'échelle ethnique et l'échelle professionnelle. On peut, donc, examiner si les évaluations des groupes ethniques et raciales démontrent moins de consensus que les évaluations des professions.
This paper establishes the existence of a ranking of ethnic and racial groups, according to social standing, within English and French Canada. Since the data used in the study were collected as part of a national study of occupational prestige, and used an identical question format, it is possible to test whether the degree of consensus in this ranking is as great as that for the ranking of occupations.