Choice of the ridge factor from the correlation matrix determinant

Ridge regression is the alternative method to ordinary least squares, which is mostly applied when a multiple linear regression model presents a worrying degree of collinearity. A relevant topic in ridge regression is the selection of the ridge parameter, and different proposals have been presented in the scientific literature. Since the ridge estimator is biased, its estimation is normally based on the calculation of the mean square error (MSE) without considering (to the best of our knowledge) whether the proposed value for the ridge parameter really mitigates the collinearity. With this goal and different simulations, this paper proposes to estimate the ridge parameter from the determinant of the matrix of correlation of the data, which verifies that the variance inflation factor (VIF) is lower than the traditionally established threshold. The possible relation between the VIF and the determinant of the matrix of correlation is also analysed. Finally, the contribution is illustrated with three real examples.     

Posterior consistency for the spectral density of non-Gaussian stationary time series

Various nonparametric approaches for Bayesian spectral density estimation of stationary time series have been suggested in the literature, mostly based on the Whittle likelihood approximation. A generalization of this approximation involving a nonparametric correction of a parametric likelihood has been proposed in the literature with a proof of posterior consistency for spectral density estimation in combination with the Bernstein–Dirichlet process prior for Gaussian time series. In this article, we will extend the posterior consistency result to non-Gaussian time series by employing a general consistency theorem for dependent data and misspecified models. As a special case, posterior consistency for the spectral density under the Whittle likelihood is also extended to non-Gaussian time series. Small sample properties of this approach are illustrated with several examples of non-Gaussian time series.     

Working and caring for a disabled adopted child during a pandemic

Integrating work and family demands can be challenging for families caring for a child with one or more disabilities. The pandemic and its changes to work, schooling and service delivery potentially added to these challenges. This exploratory mixed methods study sought to understand how the pandemic affected adoptive parents' work–life fit and service use. A total of 200 participants responded to survey questions about parenting an adopted child with a disability prior to, and after, the onset of Covid-19. More than half of the parents (59.2%) reported that it was somewhat to very difficult to integrate both work and family demands. Parents with greater access to workplace flexibility and supportive supervisors had significantly less difficulties combining work and family. Families who reported more problems with accessing mental health services, special education and respite care reported significantly more challenges with work–family fit. Parents reported increased stress due to the pandemic changes, but many also shared positive changes such as more time for family. Online services were experienced as effective for some children and reduced time spent driving to appointments. Recommendations for workplace and social service practice and policy supporting adoptive parents of children with disabilities are discussed.     

Serious case reviews: The lived experience of Black children

Despite the many high‐profile Black child deaths in England, race as a factor remains a largely underexplored factor of serious case reviews (SCRs). Evidence from analysis of SCRs indicates that race receives limited attention, or is virtually absent. Given that the main function of SCRs is to provide opportunities for learning lessons to improve practice, the way in which issues of race and culture may influence child protection processes for Black children is therefore of critical importance. In this article, we employ content analysis to examine the extent that race and cultural factors are considered in SCRs involving Black children. It is argued that race is often an important factor influencing Black children's experiences of abuse and neglect, as well as their encounters in the child protection system. This article therefore poses two key questions: (a) What questions are asked about race, ethnicity, and culture in SCRs concerning Black children? (b) How did the SCRs extract lessons to be learnt for improving practice to safeguard Black children? By extending the analysis of race and ethnicity in SCRs, this article furthers our understandings of the needs of Black children in the child protection system.     

Kulturwandel im Geldgeschäft? Potenziale einer ethischen Selbsterneuerung im Banken- und Finanzwesen

Following the financial crisis in 2008 a debate about the social benefit of the financial industry, which operates without considering its real-economic consequences, was initiated. The financial industry responded by offering strategies of cultural change (“Kulturwandel”) which foster a more socially responsible financial practice. At the same time the expansion of “ethical” banks aims to establish a banking business avoiding negative externalities of the banking sector. Following the conceptual assumptions of the sociology of critique we study the collectively shared interpretation of a “good” and legitimate financial practice beyond publicly communicated standards of practice. Against this backdrop we evaluate the potentials of normative self-regulation in banking and finance. Our results show that cultural or ethical change is only partly feasible if it exclusively focuses the motives, values and personalities of the individual subjects but neglects the structural as well as institutional conditions of a “good” financial practice.     

Evaluation of two school‐based HIV prevention interventions in the border city of Tijuana,Mexico

This research project examined the individual and combined effectiveness of an HIV prevention workshop and a free condom distribution program in four high schools in Tijuana, Mexico. Adolescents (N = 320) completed baseline measures on sexual practices and theoretical correlates and participated in a two‐part study. In Study I, students were randomly assigned to an HIV prevention workshop or a control condition, with a 3‐month follow‐up assessment. Results indicate three significant workshop benefits regarding HIV transmission by altering sexual initiation, access to condoms, and traditional beliefs regarding condoms. In Study 2, we set up a condom distribution program at two of the participating schools, and students completed a 6‐month follow‐up assessment. Results indicate that exposure to the workshop followed by access to the condom distribution program yielded two beneficial results for reducing HIV transmission: moderating sexual initiation and increasing condom acquisition. Access to the condom distribution program alone had no effects on behavioral and psy‐chosocial correlates of HFV transmission. We discuss implications of these results.