Instructions for Authors

Instructions for Authors

Instructions for Authors     

Smooth Estimation of the Reliability Function

Problems with censored data arise quite frequently in reliability applications. Estimation of the reliability function is usually of concern. Reliability function estimators proposed by Kaplan and Meier (1958), Breslow (1972), are generally used when dealing with censored data. These estimators have the known properties of being asymptotically unbiased, uniformly strongly consistent, and weakly convergent to the same Gaussian process, when properly normalized. We study the properties of the smoothed Kaplan-Meier estimator with a suitable kernel function in this paper. The smooth estimator is compared with the Kaplan-Meier and Breslow estimators for large sample sizes giving an exact expression for an appropriately normalized difference of the mean square error (MSE) of the two estimators. This quantifies the deficiency of the Kaplan-Meier estimator in comparison to the smoothed version. We also obtain a non-asymptotic bound on an expected ₁-type error under weak conditions. Some simulations are carried out to examine the performance of the suggested method.     

Navigating human rights across the life course

Issues related to human rights have increasingly moved to the forefront of professional concern in recent years. Despite this, there has been minimal attention paid to exploring how changing human needs across the lifespan impact upon human rights. This paper takes a broad look at human rights issues that occur across the life course, and uses examples of life course transitions to illuminate issues related to moral rights and human rights. The examples include family formation, raising children, adolescent maturation in the context of youth offending and grandparents parenting their grandchildren. Each example explores the contestable rights and responsibilities of children, young people and adults and the ways in which these are negotiated within the context of the family.     

Into adulthood: a follow-up study of 718 young people who were placed in out-of-home care during their teens

In this study, national register data were used to analyse long‐term outcomes at age 25 for around 700 Swedish young people placed in out‐of‐home care during their teens. The sample consisted of 70% of all 13‐ to 16‐year olds who entered out‐of‐home care in 1991. Results revealed a dividing line between young people placed in care for behavioural problems and those placed for other reasons. Young woman and men from the first group had – in comparison with peers who did not enter care – very high rates of premature death, serious involvement in crime, hospitalizations for mental‐health problems, teenage parenthood, self‐support problems and low educational attainment. Young people who were placed for other reasons had better outcomes, but still considerably worse than non‐care peers. Young women tended to do better than young men, regardless of reasons for placement. Very high rates of hospitalizations for mental health problems were found among young people placed for behavioural problems. Breakdown of placement was found to be a robust indicator of poor long‐term prognosis.     

Religiosity and preferences for life-prolonging medical treatments in African-American and white elders: a mediation study

Research on end-of-life treatment preferences has documented robust racial differences, with African-Americans preferring more life-prolonging treatment than Whites. Although little research has attempted to explain these racial differences systematically, speculation has centered on religiosity. We examined a dimension of religiosity frequently invoked in end-of-life research-guidance by God's will-as a potential mediator of racial differences in such treatment preferences. Three hundred African-American and White men and women aged 60 or older participated in a 35-minute telephone interview that elicited preferences for four common life-prolonging treatments in each of nine health scenarios. The questionnaire included the five-item God's will (GW) scale, a health conditions checklist, a depression measure, and sociodemographic questions. GW mediated racial differences at least partially for most treatments and in most health scenarios. Implications are discussed for understanding end-of-life treatment preferences and why races tend to differ.     

Efficient designs for Bayesian networks with sub-tree bounds

We present upper and lower bounds for information measures, and use these to find the optimal design of experiments for Bayesian networks. The bounds are inspired by properties of the junction tree algorithm, which is commonly used for calculating conditional probabilities in graphical models like Bayesian networks. We demonstrate methods for iteratively improving the upper and lower bounds until they are sufficiently tight. We illustrate properties of the algorithm by tutorial examples in the case where we want to ensure optimality and for the case where the goal is an approximate solution with a guarantee. We further use the bounds to accelerate established algorithms for constructing useful designs. An example with petroleum fields in the North Sea is studied, where the design problem is related to exploration drilling campaigns. All of our examples consider binary random variables, but the theory can also be applied to other discrete or continuous distributions.     

Does It Pay to Be Moral? How Indicators of Morality and Competence Enhance Organizational and Work Team Attractiveness

Based on a social identity analysis, the authors argue that people are attracted to teams and organizations with positive features. Such features can refer to the competence and achievements of the organization, or to its moral values and ethical conduct. However, in work contexts, ethics and achievements do not necessarily go together. The paper reports three studies that examine the relative and combined impact of perceived competence vs morality of a team or organization on its attractiveness to individuals. Study 1 (n = 44) reveals that students prefer to seek employment in a moral rather than a competent organization, when forced to choose between these organizational features on a bipolar scale. Study 2 (n = 100) replicates these findings in a design where the competence and morality of a fictitious organization were manipulated orthogonally. Study 3 (n = 89) examines responses to experimental task teams that systematically differed from each other in their competence and morality. Results of all three studies converge to demonstrate that the perceived morality of the team or organization has a greater impact on its attractiveness to individuals than its perceived competence. The authors discuss the theoretical and practical implications of these findings.     

Placement breakdowns in long‐term foster care – a regional Swedish study

We used a regional sample of children in long‐term foster care to investigate the prevalence of placement breakdown in adolescence, and to assess risk factors/risk markers for placement disruption. The sample consisted of all 136 foster children in the region, born 1980–1992, who on their 12th birthday had been in the same foster family for at least 4 years. They were followed in case files until date of disruption or their 18th birthday. Data on conditions before and during placement were retrieved from case files, and analysed in bi‐ and multivariate models. Results showed that one in four placements broke down in adolescence. The median child who experienced a breakdown was 14 years old, and had been in the same foster home for more than 10 years. Prominent risk factors were (i) being placed after age 2 and (ii) having a birth sibling in the same foster home. We also uncovered strong risk markers that can be viewed as precursors of placement disruption. When the child or the foster parents repeatedly over time expressed dissatisfaction with the placement, this ended with a placement breakdown in 60% of cases. Implications for practice are discussed.