Survival trees with time-dependent covariates: Application to estimating changes in the incubation period of AIDS

Tree-structured methods for exploratory data analysis have previously been extended to right-censored survival data. We further extend these methods to allow for truncation and time-dependent covariates. We apply the new methods to a data set on incubation times of acquired immunodeficiency syndrome (AIDS), using calendar time as a time-dependent covariate. Contrary to expectation, we find that rates of progression to AIDS appear to be faster after August 1989 than before.     

Household finance management and the labour market: a case study in Hartlepool

This paper reports on the results of a survey carried out in Hartlepool towards the end of 1989. It considers the problems posed by data collection through survey methods to enquire into the management of household finances, and adopts a procedure which first examines treatment of the man's wage, and follows with additional questions about use of the woman's wage, access to personal spending money, and the location of final authority over spending. The data are based on a comparsion between four different groupings with reference to the man's employment status: Group A: couples in which the man has been unemployed for at least the last 12 months. Group B: couples in which the man is currently employed and has held the same job for at least the last twelve months. Group C: couples in which the man has been recently recruited to employment. Group D: a residual group covering any other status, notably early retirement, sickness, disability or student status. An age range of 20–55 was imposed. Marked contrasts were found between these groupings though further variation was introduced by employment for the woman. Broadly speaking there are two instances of heightened financial influence for women: low income prompts female management, whilst women's employment (and therefore higher income) increases joint management. It is in the traditional and declining situation of a sole male earner in which female authority or influence is at its lowest.     

The social construction of peacekeeping in America

Although other nations have participated extensively in international peacekeeping operations, the use of American soldiers as peacekeepers is a recent change in their military role, and is not well understood by American society, the U.S. Army, the soldiers, or their wives. We use a social constructionist perspective, which has rarely been applied to the study of the American military, to analyze the definition of peacekeeping missions and of the nature of the military, by soldiers assigned to peacekeeping duty, their families, and other social institutions such as communications media and churches. We suggest that, because peacekeeping is an inherently ambiguous process, this theoretical perspective may prove useful in understanding the social definition of the emerging military role of peacekeeper.     

The Becker-DeGroot-Marschak mechanism and nonexpected utility: A testable approach

The Becker-DeGroot-Marschak mechanism is widely used to elicit decision makers' selling prices of lotteries. This mechanism leads, however, to the preference reversal phenomenon, which seemed to indicate nontransitive preferences. To solve this puzzle, Karni and Safra (1987) introduced a new interpretation of this mechanism based on two-stage lotteries without the independence axiom. In this article, we suggest a set of empirically testable hypotheses based on their interpretation of the mechanism. One of these tests can be used to find the utility and the probability transformation functions of an anticipated utility maximizer.This article consists of an earlier paper with a similar title (University of Toronto WP #8809) and the paper Elicitation of Certainty Equivalents and the Becker-DeGroot-Marschak Mechanism.     

Robust optimization in distribution-based demand planning: a model for negotiation support

In this paper a model for negotiation support in tactical procurement planning is designed, which is based on a real planning problem from the liquid gas trade sector. The problem is modeled as an assignment problem and transformed into a robust form. Computational experiments using data from a practice partner are presented to demonstrate the effective decision support of our approach.     

How Watershed Immigration Policies Affect American Public Opinion Over a Lifetime

Important political events are known to influence political socialization and development (Green, Palmquist, and Schickler 2002 ). It is also possible that such events impact political socialization within particular age cohorts, and also across important social groups who may be impacted differently by landmark events. This paper examines whether landmark immigration events can leave a permanent mark on an individual's views toward immigrants and immigration, and whether that impact varies across different ethnic/racial groups in the United States Specifically, we examine the cohort of individuals who were in their formative years during the passage of major US immigration bills that were proposed or enacted from 1965 to 2010. Altogether, we focus on four pieces of landmark immigration legislation. The findings reveal variations on the effect of these events depending on the group in question; a relationship also emerges between these landmark legislative events and attitudes on immigration policies. The analysis contributes to an ongoing debate regarding the ways in which political elites influence attitudes, and we discuss how the findings may apply to other contexts outside the US.     

Therapeutic Process as a Means to Navigate Impasse? Reflections on a Complex Case of Crosscultural Adolescent Family Therapy

This article explores the process of family therapy with a Turkish‐speaking single‐parent family with four children in which suicidal behaviour and family violence have become the norm. The following example describes a pivotal experience early within my career as a family therapist. The universality of first, being a beginner family therapist, and second, receiving a referral of a daunting, difficult case has led me to share my experience here. Central to this article is the focus on therapeutic process as a means to navigate beyond impasse. It is my hope that those who read this article will consider taking the risk to prioritise the therapeutic relationship, even when anxiety about ‘doing something’ to fix the problems is high.