Good randomized sequential probability forecasting is always possible

Summary.  Building on the game theoretic framework for probability, we show that it is possible, using randomization, to make sequential probability forecasts that will pass any given battery of statistical tests. This result, an easy consequence of von Neumann's minimax theorem, simplifies and generalizes work by earlier researchers.     

An asymptotic approach to progressive censoring

Progressive Type-II censoring was introduced by Cohen (Technometrics 5(1963) 327) and has been the topic of much research. The question stands whether it is sensible to use this sampling plan by design, instead of regular Type-II right censoring. We introduce an asymptotic progressive censoring model, and find optimal censoring schemes for location-scale families. Our optimality criterion is the determinant of the 2×2 covariance matrix of the asymptotic best linear unbiased estimators. We present an explicit expression for this criterion, and conditions for its boundedness. By means of numerical optimization, we determine optimal censoring schemes for the extreme value, the Weibull and the normal distributions. In many situations, it is shown that these progressive schemes significantly improve upon regular Type-II right censoring.     

Ecological Risk Assessment Framework for Low-Altitude Aircraft Overflights: II. Estimating Effects on Wildlife

An ecological risk assessment framework for aircraft overflights has been developed, with special emphasis on military applications. This article presents the analysis of effects and risk characterization phases; the problem formulation and exposure analysis phases are presented in a companion article. The framework addresses the effects of sound, visual stressors, and collision on the abundance and production of wildlife populations. Profiles of effects, including thresholds, are highlighted for two groups of endpoint species: ungulates (hoofed mammals) and pinnipeds (seals, sea lions, walruses). Several factors complicate the analysis of effects for aircraft overflights. Studies of the effects of aircraft overflights previously have not been associated with a quantitative assessment framework; therefore no consistent relations between exposure and population-level response have been developed. Information on behavioral effects of overflights by military aircraft (or component stressors) on most wildlife species is sparse. Moreover, models that relate behavioral changes to abundance or reproduction, and those that relate behavioral or hearing effects thresholds from one population to another are generally not available. The aggregation of sound frequencies, durations, and the view of the aircraft into the single exposure metric of slant distance is not always the best predictor of effects, but effects associated with more specific exposure metrics (e.g., narrow sound spectra) may not be easily determined or added. The weight of evidence and uncertainty analyses of the risk characterization for overflights are also discussed in this article.     

Self-Affirmation through Death: A Contribution to the Sociology of Suicide through Literature

This study contributes to the sociological study of suicide via an exploration of the implications and application of literary texts in sociological analysis. The examination of two pairs of literary texts suggests that some cases of suicide can be self-affirming. When the characters find themselves in circumstances that threaten their perception of who they are in their social contexts, they may choose the possibility of death over life with a change in self-concept. The interpretation of the four selected narrative cases of self-affirmative suicide is nestled in complexities of self-identity: two from The Iliad by Homer, and one each from Andorra and I'm Not Stiller by Max Frisch. Relating the findings to Turner's theory of impulsive versus institutional loci of real self, the article argues that institutionally constituted characters are more likely than impulsive-selves to find self-killing an acceptable resolution to their crises of identity. The findings are discussed in relation to classic theory in the sociology of suicide, concepts of the real self, and the use of literature in social science research.     

Understanding Racial and Ethnic Disparities in Arrest: The Role of Individual,Home, School,and Community Characteristics

Contact with the justice system can lead to a range of poor health and social outcomes. While persons of color are disproportionately represented in both the juvenile and criminal justice systems, reasons for these patters remain unclear. This study sought to examine the extent and sources of differences in arrests during adolescence and young adulthood among blacks, whites, and Hispanics in the USA. Multilevel cross-sectional logistic regression analyses were conducted using data from waves I and IV of the National Longitudinal Study of Adolescent to Adult Health (n = 12,752 respondents). Results showed significantly higher likelihood of having ever been arrested among blacks, when compared to whites, even after controlling for a range of delinquent behaviors (odds ratio = 1.58, 95 % confidence interval = 1.27, 1.95). These black–white disparities were no longer present after accounting for racial composition of the neighborhood, supporting the growing body of research demonstrating the importance of contextual variables in driving disproportionate minority contact with the justice system.     

Assessing the treatment effect in a randomized controlled trial with extensive non‐adherence: the EVOLVE trial

Intention‐to‐treat (ITT) analysis is widely used to establish efficacy in randomized clinical trials. However, in a long‐term outcomes study where non‐adherence to study drug is substantial, the on‐treatment effect of the study drug may be underestimated using the ITT analysis. The analyses presented herein are from the EVOLVE trial, a double‐blind, placebo‐controlled, event‐driven cardiovascular outcomes study conducted to assess whether a treatment regimen including cinacalcet compared with placebo in addition to other conventional therapies reduces the risk of mortality and major cardiovascular events in patients receiving hemodialysis with secondary hyperparathyroidism. Pre‐specified sensitivity analyses were performed to assess the impact of non‐adherence on the estimated effect of cinacalcet. These analyses included lag‐censoring, inverse probability of censoring weights (IPCW), rank preserving structural failure time model (RPSFTM) and iterative parameter estimation (IPE). The relative hazard (cinacalcet versus placebo) of mortality and major cardiovascular events was 0.93 (95% confidence interval 0.85, 1.02) using the ITT analysis; 0.85 (0.76, 0.95) using lag‐censoring analysis; 0.81 (0.70, 0.92) using IPCW; 0.85 (0.66, 1.04) using RPSFTM and 0.85 (0.75, 0.96) using IPE. These analyses, while not providing definitive evidence, suggest that the intervention may have an effect while subjects are receiving treatment. The ITT method remains the established method to evaluate efficacy of a new treatment; however, additional analyses should be considered to assess the on‐treatment effect when substantial non‐adherence to study drug is expected or observed. Copyright © 2015 John Wiley & Sons, Ltd.     

Leader-Member Exchange across two hierarchical levels of leadership: concurrent influences on work characteristics and employee psychological health

Leader-Member Exchange (LMX) theory suggests that the quality of the leader–employee relationship is linked to employee psychological health. Leaders who reside at different hierarchical levels have unique roles and spheres of influence and potentially affect employees' work experiences in different ways. Nevertheless, research on the impact of leadership on employee psychological health has largely viewed leaders as a homogeneous group. Expanding on LMX theory, we argue that (1) LMX sourced at the levels of the line manager (LM) and senior management (SM) team will be differentially linked to employee psychological health (assessed as worn-out) and that (2) these relationships will be mediated by perceived work characteristics (reward and recognition, workload management, quality of relationships with colleagues and physical environment). Structural equation modelling on data from 337 manual workers partially supported the hypotheses. Perceptions of the physical environment mediated the relationship between LMX at the LM level and employee psychological health, whereas perceptions of workload management mediated the relationship between LMX at the SM level and psychological health. These findings corroborate arguments that leaders are not a uniform group and as such the effects of LMX on employees will depend on leadership hierarchy. Implications for expanding leadership theory are discussed.     

Dimensions et effets des activités informelles dans une très petite économie

Les auteurs évaluent l'emploi informel – et les revenus non déclarés qu'il engendre – dans une très petite économie à gouvernance médiocre. Les données d'une enquěte auprès des ménages et d'un recensement leur servent à estimer le nombre de travailleurs en emploi informel à Chypre‐Nord, ainsi que les caractéristiques de cet emploi, entre 2004 et 2011. Les travailleurs concernés sont essentiellement des citoyens non affiliés à la sécurité sociale, des immigrés employés illégalement ou des personnes ayant deux emplois dont un non déclaré. L'économie informelle aurait représenté 9,1 pour cent du PNB en 2006, et 12,2 en 2011.     

Using a 'domains' approach to build community empowerment

This paper provides two case study examples of how communityempowerment can be better conceptualized, planned and appliedwithin a programme context by using a ‘domains’approach. What is new about this approach is that it does notstart with a blank slate onto which participants inscribe theirown problems or needs but provides a predetermined focus througheach of nine ‘empowerment domains’: Improves participation;Develops local leadership; Increases problem assessment capacities;Enhances the ability to ‘ask why’; Builds empoweringorganizational structures; Improves resource mobilization; Strengthenslinks to other organizations and people; Creates an equitablerelationship with outside agents; and Increases control overprogramme management. The importance to community developmentpractice is that the approach provides a more systematic meansfor community empowerment in a programme context.     

Is What’s Good for the Business,Good for the Family: A Financial Assessment

Small business prosperity doesn’t necessarily translate into family prosperity. This study utilizes the first and second waves of the National Family Business Survey to explore the influence of changes in key business financial measures on objective and subjective measures of family success. Increases in the available cash in the business from higher gross sales or net profits brings more cash into the household, while increases in the market value of the business increases the amount of money spent on other household assets. A more subjective assessment suggests that positive changes in the business financial measures create a more positive perception of the business’ success; however, these positive changes have no influence on a more positive perception of the family’s success.