A Theory of Time Preference

This article proposes that people generally prefer present consumption to future consumption because their expected utility from consumption (eventually) falls as their mental and physical abilities (eventually) decline with age. Moreover, contrary to the ubiquitous intertemporal formulation with a constant rate of time preference and contrary to three recent theories of time preference that predict decreasing discounting as people age, this article asserts that discounting increases over the life cycle. This hypothesis is supported by data from the Panel Study of Income Dynamics as well as evidence from numerous previous studies.     

‘Dirty Work?’ Gender,Race and the Union in Industrial Cleaning

The study uses an eclectic framework and through an intersectional analysis and use of narratives explores the meaning of janitorial work, the gender division of labour (GDL), the unions and organizing for janitors engaged in industrial cleaning for a big cleaning company, Pluto, in Toronto. Pluto was organized by the Service Employees International Union (SEIU) in 2006. The study is based on the organizing drive for Pluto and uses participant observation and interview methods. Intersectional analysis is useful in understanding the worker's perceptions of the racialized, gendered and classed constitution of cleaning work as ‘dirty’ and their resistance to these constructs. We explore GDL in industrial cleaning and the construction of women's work as ‘light duty’ and men's work as ‘heavy duty’. We conclude that union membership is important not only for material benefits of the janitors but also for their alternative identity construction. However, there is a persistence of GDL and gender pay equity is not addressed seriously in the organizing drive or upon organizing.     

‘Business under new management’ — lessons from Canada on regulation of the social work profession

Abstract

In December 1998 the Social Work and Social Service Work Act (hereafter the Ontario Act) was passed in Ontario, Canada marking the effective completion of social work regulatory legislation across provincial Canada. This article outlines the principal features of the Ontario regulations, and summarises the strengths and limitations of the various arrangements which have been implemented across Canada. As moves toward control of the Australian social work profession are contemplated, the implications for such a move are discussed in the light of the Canadian experience.     

Exact and approximate distributions for linear contrasts of means and variances

A Bayesian analysis is presented for the K-group Behrens-Fisher problem. Both exact posterior distributions and approximations were developed for both a general linear contrast of the K means and the K variances, given either proper diffuse or informative conjugate priors. The contrast of variances is a unique feature of the heterogeneous variance model that enables investigators to test specific effects of experimental manipulations on variance. Finally, important-differences were observed between the heterogeneous variance model and the homogeneous model.     

The cost of children. Parts II and III

In this paper the author estimates the compensating variation of income which will be necessary to keep the standard of living of a family constant when a child is born to the family. Various methods of estimation are tried, and an attempt is made to calculate the cost of a child in 1948, after allowances have been made for services provided by the government.     

On the α-risks for shewhart control charts

The performance of the usual Shewhart control charts for monitoring process means and variation can be greatly affected by nonnormal data or subgroups that are correlated. Define the α_k-risk for a Shewhart chart to be the probability that at least one “out-of-control” subgroup occurs in k subgroups when the control limits are calculated from the k subgroups. Simulation results show that the α_k-risks can be quite large even for a process with normally distributed, independent subgroups. When the data are nonnormal, it is shown that the α_k-risk increases dramatically. A method is also developed for simulating an “in-control” process with correlated subgroups from an autoregressive model. Simulations with this model indicate marked changes in the α_k-risks for the Shewhart charts utilizing this type of correlated process data. Therefore, in practice a process should be investigated thoroughly regarding whether or not it is generating normal, independent data before out-of-control points on the control charts are interpreted to be due to some real assignable cause.     

Graphical and Numerical Methods for Detecting Influential Observations in Complex Bingham Data

We describe methods to detect influential observations in a sample of pre-shapes when the underlying distribution is assumed to be complex Bingham. One of these methods is based on Cook's distance, which is derived from the likelihood of the complex Bingham distribution. Other method is related to the tangent space, which is based on the local influence for the multivariate normal distribution. A method to detect outliers is also explained. The application of the methods is illustrated in both a real dataset and a simulated sample.