A Class of Convolution‐Based Models for Spatio‐Temporal Processes with Non‐Separable Covariance Structure

Abstract. In this article, we propose a new parametric family of models for real‐valued spatio‐temporal stochastic processes S ( x , t ) and show how low‐rank approximations can be used to overcome the computational problems that arise in fitting the proposed class of models to large datasets. Separable covariance models, in which the spatio‐temporal covariance function of S ( x , t ) factorizes into a product of purely spatial and purely temporal functions, are often used as a convenient working assumption but are too inflexible to cover the range of covariance structures encountered in applications. We define positive and negative non‐separability and show that in our proposed family we can capture positive, zero and negative non‐separability by varying the value of a single parameter.     

ENVIRONMENTAL REGULATION: WHOSE SELF-INTERESTS ARE BEING PROTECTED?

Special interest can explain why environmental policy limits economic activity in areas where air quality is above minumum standards. Locational competition among region helped create a policy that raised factor mobility cost from slower to faster growing regions. Analysis of votes shows greater support for this policy was received from northern urban constituencies and the greatest opposition came from the South and the West. Pollution abatement costs per unit of output are higher in areas with higher not lower air quality.     

Work,family and the care of children: issues of equality and responsibility

SUMMARY. The current growth in women's employment, particularly among women with young children, gives new prominence to an issue of major political, economic and social importance, involving men as well as women and children: the relationship between paid work and family responsibilities and how to reconcile these demands without creating inequalities or stress for children or parents, especially mothers. The paper considers the Government's response to this development, arguing that it should be taking a strategic or leadership role, working in active partnership with employers, trades unions, local authorities, voluntary organisations and parents. Examples from Sweden, Spain and New Zealand are given to illustrate this alternative approach     

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.     

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.     

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.