Sampling distributions of kruskal's measure of stress for an asymmetric matrix

In the past ten years multidimensional scaling of nonmetric data has been widely applied in behavioral and business research. This paper investigates the asymmetric data matrix and develops stress distributions based upon a null hypothesis of equal like­lihood in the ranking of a set of proximities.     

Risk-Management and Risk-Analysis-Based Decision Tools for Attacks on Electric Power

Incident data about disruptions to the electric power grid provide useful information that can be used as inputs into risk management policies in the energy sector for disruptions from a variety of origins, including terrorist attacks. This article uses data from the Disturbance Analysis Working Group (DAWG) database, which is maintained by the North American Electric Reliability Council (NERC), to look at incidents over time in the United States and Canada for the period 1990-2004. Negative binomial regression, logistic regression, and weighted least squares regression are used to gain a better understanding of how these disturbances varied over time and by season during this period, and to analyze how characteristics such as number of customers lost and outage duration are related to different characteristics of the outages. The results of the models can be used as inputs to construct various scenarios to estimate potential outcomes of electric power outages, encompassing the risks, consequences, and costs of such outages.     

The welfare economics of immigration control

This paper develops a Harris-Todaro (HT) type model of East-West migration in which labour market imperfections prevent market clearing in both blocs. The model encompasses two extremes of perfectly flexible wages with full employment on the one hand, and the HT scenario where the real wage in the host country is fixed, on the other. Welfare analysis compares the laissez-faire migration equilibrium based on explicit calculations of potential migrants without immigration controls in the West, with the socially optimal level of migration. The paper examines the issue of immigration control by developing a model of illegal immigration in which the incentives facing the potentially illegal immigrant are explicitly modelled. Received: 3 April 1997/Accepted 16 March 1998     

More present than absent: Men who use domestic violence and their fathering

An earlier article referred to the “absent presence” of the perpetrator in the lives of children and their mothers who have lived with domestic violence. It identified the ways in which the shadow of the perpetrator continued and was evidenced in the “symptoms of abuse” that both women and children experienced in spite of his absence. The current article argues that fathers who use violence are actually more present than absent in the lives of children (and women), even following separation. A mixed method approach surveyed men in Men's Behaviour Change Programs (N = 101), and interviewed women who had experienced violence (N = 50). The studies reported that the majority of men in both the quantitative men's study (80%) and the qualitative women's study (77%) had substantial contact with children. The women's interviews highlight the problematic fathering that many of their children experienced, both before and after separation. They reported very high levels of child abuse and poor attitudes to both women and children. The article concludes that the family violence and child welfare systems are poorly configured to address fathers who use violence and continue to hold substantial parenting roles, including following separation.     

Adapting the jury trial for program evaluation: A report of an experience

A portion of the graduate program in clinical community psychology at SUNY Buffalo was subjected to a jury trial as a form of program evaluation. The theory of the trial as evaluation, the problems of implementation, and a posttrial evaluation are discussed. The trial, while time-consuming, especially in its pretrial phases, has the potential for presenting a dramatic picture of a program through the medium of human testimony. The jury was able to arrive at clear decisions on questions put to it, with a high degree of confidence. Decision makers accepted some of the jury's conclusions, and subjective evidence suggests that many of the controversial issues which generated the trial were resolved for the group by the procedure. The posttrial evaluation revealed limitations, such as evidence which was not presented at the trial. The experience proved useful for purposes of interdisciplinary education, providing another lens through which the evaluation problem could be viewed.     

Modeling Longitudinal Obesity Data with Intermittent Missingness Using a New Latent Variable Model

We propose a latent variable model for informative missingness in longitudinal studies which is an extension of latent dropout class model. In our model, the value of the latent variable is affected by the missingness pattern and it is also used as a covariate in modeling the longitudinal response. So the latent variable links the longitudinal response and the missingness process. In our model, the latent variable is continuous instead of categorical and we assume that it is from a normal distribution. The EM algorithm is used to obtain the estimates of the parameter we are interested in and Gauss–Hermite quadrature is used to approximate the integration of the latent variable. The standard errors of the parameter estimates can be obtained from the bootstrap method or from the inverse of the Fisher information matrix of the final marginal likelihood. Comparisons are made to the mixed model and complete-case analysis in terms of a clinical trial dataset, which is Weight Gain Prevention among Women (WGPW) study. We use the generalized Pearson residuals to assess the fit of the proposed latent variable model.