Robustness of Approaches to ROC Curve Modeling under Misspecification of the Underlying Probability Model

A variety of statistical regression models have been proposed for the comparison of ROC curves for different markers across covariate groups. Pepe developed parametric models for the ROC curve that induce a semiparametric model for the market distributions to relax the strong assumptions in fully parametric models. We investigate the analysis of the power ROC curve using these ROC-GLM models compared to the parametric exponential model and the estimating equations derived from the usual partial likelihood methods in time-to-event analyses. In exploring the robustness to violations of distributional assumptions, we find that the ROC-GLM provides an extra measure of robustness.     

Prediction Techniques for Box–Cox Regression Models

This article reviews several techniques useful for forming point and interval predictions in regression models with Box-Cox transformed variables. The techniques reviewed—plug-in, mean squared error analysis, predictive likelihood, and stochastic simulation—take account of nonnormality and parameter uncertainty in varying degrees. A Monte Carlo study examining their small-sample accuracy indicates that uncertainty about the Box–Cox transformation parameter may be relatively unimportant. For certain parameters, deterministic point predictions are biased, and plug-in prediction intervals are also biased. Stochastic simulation, as usually carried out, leads to badly biased predictions. A modification of the usual approach renders stochastic simulation predictions largely unbiased.     

Understanding perceptions of substance use education in social work: an analysis of survey responses from MSW program leaders

ABSTRACT

This article details the findings of a series of analyses regarding how the institutional leaders of Master of Social Work Programs (MSW) in the United States form their perceptions on the role and implementation of substance use concepts in social work education. Five statistical tests were performed on data collected from a 2017 substance use education (SUE) survey of MSW program leaders, and the analyses were used to explore how program leaders form their perceptions on: the importance of SUE to social work, the need for regulatory measures for SUE in social work, the SUE needs of individual MSW programs, the implementation of substance use course content, and graduating students’ substance use intervention capacities. Significant findings from the analyses showed that: the amount of foundational course emphasis on clinical SUE within individual programs is a significant predictor of program leader perceptions on students’ clinical substance use intervention capacities; different categories of substance use intervention preparedness have interconnected effects among domains of preparedness; and perceptions on the importance of SUE to social work have a significant impact on program leaders’ opinions regarding regulatory measures for SUE in social work.     

FDI,democracy and corruption in Sub-Saharan Africa

This paper investigates the relationship between FDI, democracy and corruption among 30 countries in Sub-Saharan Africa (SSA) over the period of 1985–2014 to determine whether the ‘helping hand’ or ‘grabbing hand’ hypothesis is most applicable. The results of GMM analysis show that corruption is used by FDI investors to overcome the region’s weak democratic regulatory and institutional status and thus the ‘helping hand’ is more prevalent. However, the results further show that as democratic capital accumulates, this association may outlive its usefulness and thus corruption as a ‘helping hand’ in time becomes a ‘grabbing hand’ instead. These results imply that SSA countries should focus on integrating into the international economy so as to take advantage of existing financial enforcement legislation while reconstructing and strengthening domestic constitutional anti-corruption legislation and institutions.     

The social context of Welsh-medium bilingual education in anglicised areas

Principal component analysis of indicators from the 1991 Census was used to characterise the social context of school age Welsh speakers in South East Wales. The area had been largely anglicised by the Census of 1971, but the growth of Welsh-medium education was responsible for net gains in numbers of younger Welsh/English bilinguals. Doubts as to whether young people will remain active bilinguals after leaving school have been raised. The inter-relationships between figures for Welsh speaking in the Census and other social indicators were examined. Being categorised as a young Welsh speaker was found to cut across an economic advantage/disadvantage dimension, and so was a matter of life style rather than a by-product of parental choices unrelated to language resurgence. Probing life styles by means of interviews where Welsh-medium and English-medium schools could be matched on the economic advantage/disadvantage dimension showed that deciding for Welsh-medium education was embedded in authentic local life styles. Although networks of people at more local spatial scales were involved in Welsh-medium education, they were linked to wider scale networks establishing domains for Welsh language use in the public sector and local government.     

Leadership efficacy: Review and future directions

The concept of leader efficacy has received relatively little attention in the leadership literature. This is somewhat surprising given that effective leadership requires high levels of agency (i.e., deliberately or intentionally exerting positive influence) and confidence. This review uses existing theory and research on leader efficacy as a point of departure for proposing an expanded and multi-level framework for understanding the domain of leadership efficacy that includes leader, follower, and collective efficacies. The primary goals are to provide a conceptual framework to stimulate future theory and research on building efficacious leadership and to understand how such leadership develops and has implications for effective performance.     

The Schwarzian derivative as a ranking of downside risk aversion

It is observed that the measure S _u  = u′′′/u′ − (3/2)(u′′/u′)², previously shown to be a relevant measure of the degree of downside risk aversion, is known in the mathematics literature as the Schwarzian derivative. The Schwarzian derivative has invariance properties under composition of functions that make it particularly well-behaved as a ranking of downside risk aversion. Indeed, it has the same invariance properties as the measure R _u  = −u′′/u′, familiar to economists as a ranking of utility functions by degree of Arrow-Pratt risk aversion.     

Exposure to Community Violence,Suicidality, and Psychological Distress Among African American and Latino Youths: Findings From the CDC Youth Violence Survey

The present investigation explored risk and protective factors for suicidal ideation and behavior in a sub-sample of African American and Latino adolescents (n = 2,626) who participated in the 2004 Centers for Disease Control Youth Violence Survey. Structural equation modeling was used to explore exposure to violence at the community level as a contextual factor that could potentially influence depressive symptomatology, substance abuse, parental support, social support, and suicidality among study participants. Findings indicated that exposure to violence at the community level was not directly related to suicidality among this population of urban adolescents. However, it was directly related with several other variables under study in the model, which in turn were directly related with suicidality. Tests of invariance revealed several across-group differences, particularly by race and gender, in how the identified risk and protective factors in the model related to suicidality. Implications for research and practice with urban, ethnic minority, adolescent populations are discussed.     

A Texas Peasantry? Black Smallholders in the Texas Sugar Bowl, 1865–1890

This article examines a small community of former slaves in Texas's leading sugar-producing county and argues that local conditions fostered the growth of a Caribbean-style ‘reconstituted peasantry’. Using local sources to compile a database of 79 African American landowners, it traces the postwar decline of the sugar plantations, the process of black land acquisition and the smallholders' strategies for survival. The smallholders' position, however, was precarious, and most lost their lands at the close of the nineteenth century. The piece concludes by suggesting that more intensive local research into former-slave communities may force a reconsideration of the notion that all American slaves became landless wage labourers.     

Being Known in Undergraduate Social Work Education: The Role of Instructors in Fostering Student Engagement and Motivation

Most undergraduate students pursue a social work major because of their desire to help others. Students tend to be more interested in doing than in understanding the research and knowledge of the profession and the complexities of social work practice. Instructors are often faced with the challenge of enhancing student motivation to learn challenging course material. This study explored student perceptions of instructor influences on their motivation and engagement in learning. Through online surveys, students described their experiences of being known and how those experiences affected their participation in practice, research, and human behavior in the social environment courses. Results showed that instructor caring (providing recognition, expressing relational qualities, and responding to students) positively influences student motivation and affective learning by increasing comfort, willingness to ask questions, take risks, and overall participation. Conversely, of those who reported mixed experiences or who felt unknown, most reported a negative impact on their motivation and participation. These findings suggest that social work faculty can influence student motivation and engagement with essential social work curriculum by expressing care and helping students feel known in the classroom.