Umvu estimators for the population mean and variance based on random effects models for lognormal data

Cross-classified data are often obtained in controlled experimental situations and in epidemiologic studies. As an example of the latter, occupational health studies sometimes require personal exposure measurements on a random sample of workers from one or more job groups, in one or more plant locations, on several different sampling dates. Because the marginal distributions of exposure data from such studies are generally right-skewed and well-approximated as lognormal, researchers in this area often consider the use of ANOVA models after a logarithmic transformation. While it is then of interest to estimate original-scale population parameters (e.g., the overall mean and variance), standard candidates such as maximum likelihood estimators (MLEs) can be unstable and highly biased. Uniformly minimum variance unbiased (UMVU) cstiniators offer a viable alternative, and are adaptable to sampling schemes that are typiral of experimental or epidemiologic studies. In this paper, we provide UMVU estimators for the mean and variance under two random effects ANOVA models for logtransformed data. We illustrate substantial mean squared error gains relative to the MLE when estimating the mean under a one-way classification. We illustrate that the results can readily be extended to encompass a useful class of purely random effects models, provided that the study data are balanced.     

The robustness of the likelihood ratio test,the nonparametric sum rank test,and f-ratio tests when the populations are from the negative binomial family

In this study, the robustness of power and significance level of several statistical testing methods was evaluated under the assumption that the test populations were from Poisson, negative binomial, or geometric distributions. The F-ratio test, with or without appropriate transformations, was shown to be both safe and robust for all distributions examined.     

Issues in blinded sample size re-estimation

The utility of blinded sample size re-estimation for clinical trials depends on the ability to estimate variability without providing information about the true treatment difference, and on some reasonable assurance that the method is not likely to cause the sample size to be increased when the treatment effect is better than anticipated. We show that violations of these properties are unlikely to occur in practice.     

360 Video: A prototyping process for developing virtual reality interventions

Abstract

Virtual reality (VR) has emerged as a promising technological intervention for anxiety disorders. However, there are no existing standards and best practices to evaluate the effectiveness of environments to achieve their intervention goals. The purpose of this study was to develop a VR intervention for student veterans with social anxiety disorder and test feasibility utilizing a three-stage development model. The development of a therapeutic VR environment may benefit from an interdisciplinary collaboration of researchers from various fields of study. Utilizing three stages of prototyping with two virtual reality platforms, fully immersive video (n?=?6) and three-dimensional (3-D) immersive virtual reality (n?=?8), the research team designed an intervention for student veterans with social anxiety disorder, testing bio-reactivity of participants. Results of prototyping include user feedback validating increased stress levels and increased bio-reactivity specifically in galvanic skin response and heart rate elevation. Implications include the use of 360° video for prototyping 3-D virtual reality interventions.     

Experimental Coastal Land Reclamation: Qianhai as a Case Interpreted

ABSTRACT

Informed by a Coasian transaction cost paradigm enriched by the concept of Schumpeterian innovations, this paper discusses the advantages of using experimental coastal reclamation of the sea to build new cities with a policy for fostering innovations. A new development area at the margin of Shenzhen in China, Qianhai, is used to demonstrate how urban expansion by urban sprawling in a megacity can be avoided by reclamation of marginal land as analytically less costly than along intra-marginal land and more suitable for experimentation for the type of megacity concept that Qianhai aims to achieve.     

Family Policy and Complex Contemporary Families: A Decade in Review and Implications for the Next Decade of Research and Policy Practice

Prior Journal of Marriage and Family decade-in-review articles have grappled with the definition and role of family policy for research and policy practice while emphasizing its value to both. In this article, we begin with a broad conceptualization of family policy that encompasses actions intended to achieve explicitly stated goals for families (explicit policies) and those that affect families without an explicitly stated goal for doing so (implicit policies), which we believe provides a solid framework for guiding and understanding both research and practice in the field. Second, we review major U.S. policy initiatives in the past decade and their documented and potential effects on families. Third, we describe several key aspects by which contemporary families have become more diverse and complex. Fourth, we discuss the implications of ongoing family complexity for public policies. We conclude with a discussion about future research and policy development in the context of contemporary family complexity.     

ANTITRUST ECONOMICS AND CONSUMER PROTECTION ECONOMICS IN POLICY AND LITIGATION: WHY THE DISPARITY?

The lag in the use of microeconomics in consumer protection policy and litigation—as compared with the use of microeconomics in antitrust/competition policy and litigation—has at least three causes: a considerably shorter period of intellectual development; the specific historical origins and culture of the U.S. Federal Trade Commission (FTC), where this disparity is especially noticeable; and the splintering of consumer protection responsibilities across a very large number of federal and state agencies. This paper will expand on these themes and discuss their implications—including the opportunities for expanded research in the area of consumer protection economics. (JEL B12, B13, B21, D18, L41)     

Parenting and child-caretaking among black men who have sex with men and associated sexual and reproductive health factors: a brief report

Abstract

The purpose of this exploratory study was to examine the prevalence of parenting and child-caretaking among a sample of black men who have sex with men (MSM), as well as associations between parenting roles and sexual and reproductive health (SRH) factors. Parenting and SRH data were derived from a survey of 199 black MSM. Nearly half of the sample reported being a father or father-figure (44.4%), almost a third indicated serving as caretaker of a child (29.1%), and one in five have a biological child (20.1%). Over half of the sample reported at least one of these three parenting/child-caretaking roles (52.5%). Two significant differences were observed for sexual health variables: men with biological children were significantly more likely to report using condoms inconsistently (55.0% vs. 35.7%, p = .026) and engaging in transactional sex work (36.8% vs. 21.0%, p = .041). Given the observed prevalence, parenting and child-caretaking among black MSM warrant further inquiry as factors that may influence SRH outcomes and care utilization. Services and interventions tailored to black MSM should consider these men’s potential roles and responsibilities as parents and caretakers of children.