Modelling the management of underground water assets

Central to the activities of any industry is the modernization of its assets. This paper describes the application of statistical methods to the asset management plan of a large water company. A model for the underground assets is given in detail, and the extensive computations required are illustrated. A Bayesian model shows the consequences of various policy options and provides realistic measures of the uncertainty connected with them.     

Reports of Conferences, Institutes, and Seminars

Reports on the 2005 North Carolina Serials Conference, the twentieth anniversary conference of the North American Serials Interest Group, the 2005 Acquisitions Institute at Timberline Lodge, and a program on electronic archiving sponsored by the New England Chapter of the Association of College and Research Libraries.     

Black Homeownership: The Role of Temporal Changes and Residential Segregation at the End of the 20th Century*

Objective. This study examines how the odds of a black renter becoming a homeowner changed during the 1990s, considering significant policy changes aimed at dismantling discriminatory barriers to nonwhite homeownership during that time period and various housing‐market characteristics, including the level of residential segregation. Methods. This study uses geocoded data from the Panel Study of Income Dynamics and from the 1990 and 2000 Censuses to estimate an event‐history model of transition into homeownership for black Americans. Results. The results of this study suggest that blacks benefited from the changing home‐lending environment and were more likely to become homeowners during the 1990s. These improvements appear to be both absolute and relative to whites. This implies that the policy changes had some success. Nevertheless, blacks were significantly less likely to become homeowners during the study period—even after controlling for a variety of factors known to be associated with homeownership—suggesting that further reforms may be necessary to eradicate disparities in access to homeownership between whites and blacks. The analysis also shows that blacks residing in metro areas with the highest levels of racial isolation were significantly more likely to become homeowners than blacks residing in metro areas with the lowest levels of isolation. Conclusion. The study results show that the policy reforms of the 1990s likely had a salutary effect on black homeownership. The results also suggest that residential segregation matters to black homeownership in complex ways.     

A scientist's viewpoint on promoting effective use of experimental design: Ten things a scientist wants to know about experimental design

This paper tackles the practical application of statistical tools. Chemical development is a rich area for collaboration between statisticians and chemists, but most statisticians encounter difficulties in promoting the tools to this client group. This paper, presented from a chemist's perspective, is intended to help bridge the gap between the two professions. The paper explores differences in uptake and attitudes towards adopting these techniques and suggests what has hindered or helped the process of effective application of experimental design. Copyright © 2003 John Wiley & Sons, Ltd.     

Body Weight and Matching With a Physically Attractive Romantic Partner

Matching and attribute trade are two perspectives used to explain mate selection. We investigated patterns of matching and trade, focusing on obesity, using Add Health Romantic Pair data (N = 1,405 couples). Obese individuals, relative to healthy weight individuals, were less likely to have physically attractive partners, with this disadvantage greater for women than men, and greater for White women than Black women. Additional education, a more attractive personality, and better grooming increased the probability of having a physically attractive partner and offset the disadvantage of obesity for some individuals. Unexpectedly, we found women, like men, trade education for their partners’ physical attractiveness. Despite evidence of attribute trade, matching with respect to physical characteristics was the dominant mate selection pattern.     

Spheres,cubes and boxes: Graph dimensionality and network structure

This is an examination of a set of dimensional conceptions of graphs that might be used to shed light on the structural complexity of social networks. Problems of characterizing various conceptions are explored and computational methods are reviewed.     

Modelling age variation in survival and reporting rates for recovery models

In this paper, we focus on models for recovery data from birds ringed as young. In some cases, it is important to be able to include in these models a degree of age variation in the reporting probability. For certain models this has been found, empirically, to result in completely flat likelihood surfaces, due to parameter redundancy. These models cannot then be fitted to the data, to produce unique parameter estimates. However, empirical evidence also exists that other models with such age variation can be fitted to data by maximum likelihood. Using the approach of Catchpole and Morgan (1996b), we can now identify which models in this area are parameter-redundant, and which are not. Models which are not parameter-redundant may still perform poorly in practice, and this is investigated through examples, involving both real and simulated data. The Akaike Information Criterion is found to select inappropriate models in a number of instances. The paper ends with guidelines for fitting models to data from birds ringed as young, when age dependence is expected in the reporting probability.     

Parents: Dilemmas for Professionals

A professional critically examines her practices towards parents whilst an educational psychologist. Aspects of the power relationship are explored, including acting as a friend, the trappings of professionalism, privacy and confidentiality, interprofessional trust, and the provision of services. A tentative conclusion reached is that these create dilemmas which are part of the workings of the system within which the educational psychologist works, and that professional survival is the underlying motive.