Psycho-Drama as a Medium for Intermediate Treatment

Summary This paper is an account of an Intermediate Treatment Groupset up in February 1975. It uses spontaneous drama as its onlyactivity. It is argued that this provides general personal growthin a supportive atmosphere as well as allowing experimentationwith specific problem situations. The methods used are describedand an attempt is made to discuss the dynamics involved in theseprocesses.     

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     

PRODUCT DIFFERENTIATION UNDER CONGESTION: HOTELLING WAS RIGHT

We introduce negative network externalities—“congestion costs”—into H. Hotelling's (1929) model of spatial competition with linear transportation costs. For any firm locations on opposite sides of the midpoint, a pure strategy price equilibrium exists and is unique if congestion costs are strong enough relative to transportation costs. We analyze product differentiation and find that Hotelling's Principle of Minimum Differentiation comes closer to holding in the presence of congestion costs. The greater are congestion costs, the less differentiated products can be in (locationally symmetric) equilibrium. In fact, minimum differentiation comes arbitrarily close to holding depending on the magnitude of these costs relative to transportation costs. Intuitively, greater congestion effects stabilize competition at closer quarters, eliminating aggressive pricing equilibria. Thus, negative network externalities can play a significant role in product differentiation. (JEL D21, L15, R12)     

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.