Stochastically optimal bootstrap sample size for shrinkage-type statistics

In nonregular problems where the conventional \(n\) out of \(n\) bootstrap is inconsistent, the \(m\) out of \(n\) bootstrap provides a useful remedy to restore consistency. Conventionally, optimal choice of the bootstrap sample size \(m\) is taken to be the minimiser of a frequentist error measure, estimation of which has posed a major difficulty hindering practical application of the \(m\) out of \(n\) bootstrap method. Relatively little attention has been paid to a stronger, stochastic, version of the optimal bootstrap sample size, defined as the minimiser of an error measure calculated directly from the observed sample. Motivated by this stronger notion of optimality, we develop procedures for calculating the stochastically optimal value of \(m\). Our procedures are shown to work under special forms of Edgeworth-type expansions which are typically satisfied by statistics of the shrinkage type. Theoretical and empirical properties of our methods are illustrated with three examples, namely the James–Stein estimator, the ridge regression estimator and the post-model-selection regression estimator.     

Variable selection for survival data with a class of adaptive elastic net techniques

The accelerated failure time (AFT) models have proved useful in many contexts, though heavy censoring (as for example in cancer survival) and high dimensionality (as for example in microarray data) cause difficulties for model fitting and model selection. We propose new approaches to variable selection for censored data, based on AFT models optimized using regularized weighted least squares. The regularized technique uses a mixture of \(\ell _1\) and \(\ell _2\) norm penalties under two proposed elastic net type approaches. One is the adaptive elastic net and the other is weighted elastic net. The approaches extend the original approaches proposed by Ghosh (Adaptive elastic net: an improvement of elastic net to achieve oracle properties, Technical Reports 2007) and Hong and Zhang (Math Model Nat Phenom 5(3):115–133 2010), respectively. We also extend the two proposed approaches by adding censoring observations as constraints into their model optimization frameworks. The approaches are evaluated on microarray and by simulation. We compare the performance of these approaches with six other variable selection techniques-three are generally used for censored data and the other three are correlation-based greedy methods used for high-dimensional data.     

Investigating impacts of complex sampling on latent growth curve modelling

We investigate the impacts of complex sampling on point and standard error estimates in latent growth curve modelling of survey data. Methodological issues are illustrated with empirical evidence from the analysis of longitudinal data on life satisfaction trajectories using data from the British Household Panel Survey, a national representative survey in Great Britain. A multi-process second-order latent growth curve model with conditional linear growth is used to study variation in the two perceived life satisfaction latent factors considered. The benefits of accounting for the complex survey design are considered, including obtaining unbiased both point and standard error estimates, and therefore correctly specified confidence intervals and statistical tests. We conclude that, even for the rather elaborated longitudinal data models that were considered, estimation procedures are affected by variance-inflating impacts of complex sampling.     

Methods to assess measurement error in questionnaires of sedentary behavior

Sedentary behavior has already been associated with mortality, cardiovascular disease, and cancer. Questionnaires are an affordable tool for measuring sedentary behavior in large epidemiological studies. Here, we introduce and evaluate two statistical methods for quantifying measurement error in questionnaires. Accurate estimates are needed for assessing questionnaire quality. The two methods would be applied to validation studies that measure a sedentary behavior by both questionnaire and accelerometer on multiple days. The first method fits a reduced model by assuming the accelerometer is without error, while the second method fits a more complete model that allows both measures to have error. Because accelerometers tend to be highly accurate, we show that ignoring the accelerometer's measurement error, can result in more accurate estimates of measurement error in some scenarios. In this article, we derive asymptotic approximations for the mean-squared error of the estimated parameters from both methods, evaluate their dependence on study design and behavior characteristics, and offer an R package so investigators can make an informed choice between the two methods. We demonstrate the difference between the two methods in a recent validation study comparing previous day recalls to an accelerometer-based ActivPal.     

“It has given me life.” Latinas and the U-Visa: A Qualitative Study

Women, particularly undocumented women, are at an increased risk for gender-based violence including intimate partner violence (IPV). Women’s lack of legal immigration status is often used as a tool of dominance and control of undocumented women. The Victim of Trafficking and Violence Prevention Act 2000 created the U-Visa that provides undocumented IPV victims with lawful immigration status if they are willing to assist authorities in investigating crimes. The objective of this study is to better understand the benefits of obtaining the U-Visa from the perspectives of Latina U-Visa recipients who are survivors of IPV. In this community-based qualitative research study involving IPV survivors, community leaders, service providers and academics, we collected qualitative data through interviews with 20 participants including 15 survivors of IPV who were U-Visa recipients. Interviews were digitally-recorded, transcribed and translated, and analyzed using a qualitative software to develop key themes. Women received a $20 gift card as a token of appreciation for their participation in this study. Findings highlight key benefits such as improved mental health, renewed confidence and self-esteem, self-confidence, less perceived exploitation, access to better jobs and housing, freedom to travel, and improved economic and social well-being for visa recipients and their families. Obtaining the U-Visa was a transformative and life-changing experience for Latina survivors of IPV. Social policies such as TVPA help support vulnerable women who are victims of IPV.     

Eminent Social Scientists’ Views on Immigration Issues: 1985 and 2006

Following up on a research note by Stephen Moore published in 1985, this article compares the results of the survey conducted in 1985 against one carried out in 2006 on the views of eminent social scientists (economists, political scientists, psychologists, sociologists, historians and anthropologists) on immigration issues. Specifically, the surveys report on whether the respondents are likely to favor an increase in the number of immigrants who are allowed into the United States and other issues such as whether immigrants improve the economy.

---

“Grace Is Deceitful and Beauty Is Vain”: How Hassidic Women Cope with the Requirement of Shaving One’s Head and Wearing a Black Kerchief

Women’s modesty norms are often perceived as governing women’s bodies and as patriarchal oppression. This study challenges these perspectives, offering a deeper, multi-dimensional picture showing that the reality of the women’s life is much more complicated. The article chose to discuss aspects of modesty among women of one of the most extreme Jewish ultra-Orthodox groups, and in particular, to investigate how they experience an extremely demanding requirement—shaving off the hair on their head upon marriage and covering their head with a black kerchief. The findings show that there are a variety of voices among the women, ranging from the view that these practices are desirable, through the view that they empower the women, to the view that they damage one’s attractiveness and are quite painful.

Domestic violence screening and service acceptance among adult victims in a dependency court setting

Many child welfare systems are unable to effectively identify and address co-occurring domestic violence and child maltreatment. In response, the Dependency Court Intervention Program for Family Violence implemented a protocol to identify indicators of domestic violence in families involved with child protection proceedings. This article highlights data that demonstrate the ability of an outreach and screening process to identify adult victims of domestic violence in dependency court and to offer them appropriate intervention services.