Second-order variance estimation in poststratified two-stage sampling

The linearization or Taylor series variance estimator and jackknife linearization variance estimator are popular for poststratified point estimators. In this note we propose a simple second-order linearization variance estimator for the poststratified estimator of the population total in two-stage sampling, using the second-order Taylor series expansion. We investigate the properties of the proposed variance estimator and its modified version and their empirical performance through some simulation studies in comparison to the standard and jackknife linearization variance estimators. Simulation studies are carried out on both artificially generated data and real data.     

Using bootstrap method to evaluate the estimates of nicotine equivalents from linear mixed model and generalized estimating equation

Twenty-four-hour urinary excretion of nicotine equivalents, a biomarker for exposure to cigarette smoke, has been widely used in biomedical studies in recent years. Its accurate estimate is important for examining human exposure to tobacco smoke. The objective of this article is to compare the bootstrap confidence intervals of nicotine equivalents with the standard confidence intervals derived from linear mixed model (LMM) and generalized estimation equation. We use percentile bootstrap method because it has practical value for real-life application and it works well with nicotine data. To preserve the within-subject correlation of nicotine equivalents between repeated measures, we bootstrap the repeated measures of each subject as a vector. The results indicate that the bootstrapped estimates in most cases give better estimates than the LMM and generalized estimation equation without bootstrap.     

Semiparametric Stein estimators

Stein [Stein, C. (1956). Inadmissibility of the usual estimator for the mean of a multivariate normal distribution. In Proc. 3rd Berkeley symp. math. statist. and pro. (pp. 197–206). University of California Press], in his seminal paper, came up with the surprising discovery that the sample mean is an inadmissible estimator of the population mean in three or higher dimensions under squared error loss. The past five decades have witnessed multiple extensions and variations of Stein’s results. In this paper we develop Stein-type estimators in a semiparametric framework and prove their coordinatewise asymptotic dominance over the sample mean in terms of Bayes risks.     

The Socioeconomic Attainments of Non-immigrant Cambodian, Filipino, Hmong, Laotian, Thai, and Vietnamese Americans

Using recent American Community Survey data, this study investigates socioeconomic attainments of six ethnic groups of Southeast Asian Americans. Findings show that the educational attainment of Filipinos, Vietnamese, and Thai is higher than that of whites, while the educational attainment of Cambodians, Hmong, and Laotians is lower than that of whites. Regarding earnings, Southeast Asian American women are generally not disadvantaged relative to white women, but Southeast Asian American men tend to have lower earnings than white men after controlling for education and other demographic factors such as age, metropolitan residence, and region. We conclude that Cambodians, Hmong, and Laotians are the most disadvantaged groups among Southeast Asian Americans and that most Southeast Asian American male groups tend to be at least slightly disadvantaged in the labor market at least after controlling for metropolitan residence and region.     

Bayesian analysis of generalized odds-rate hazards models for survival data

In the analysis of censored survival data Cox proportional hazards model (1972) is extremely popular among the practitioners. However, in many real-life situations the proportionality of the hazard ratios does not seem to be an appropriate assumption. To overcome such a problem, we consider a class of nonproportional hazards models known as generalized odds-rate class of regression models. The class is general enough to include several commonly used models, such as proportional hazards model, proportional odds model, and accelerated life time model. The theoretical and computational properties of these models have been re-examined. The propriety of the posterior has been established under some mild conditions. A simulation study is conducted and a detailed analysis of the data from a prostate cancer study is presented to further illustrate the proposed methodology.     

Life after loss: Comparing student service member/veteran and civilian mental health characteristics among individuals exposed to death by suicide

Objective: This study evaluated the mental health characteristics and beliefs of student service members/veterans (SSM/Vs) who have been exposed to another’s death by suicide.

Participants: A total of 39 SSM/Vs exposed to suicide and 32 SSM/Vs not exposed to suicide were sampled from a larger, epidemiological survey. An age- and gender-matched group of 39 civilian (C) students was drawn from a larger sample of individuals exposed to suicide.

Methods: Data were collected as part of an Internet-based, campus needs survey that occurred in Fall 2014. Participants were asked to complete measures about suicide-related behaviors, suicide prevention, help-seeking, and demographics.

Results: SSM/Vs exposed to suicide had more positive mental health/suicide prevention beliefs than SSM/Vs not exposed to suicide. Cs exposed to suicide were not significantly different from either group. Unique help-seeking patterns were also identified.

Conclusions: The current study identifies unique characteristics of SSM/Vs exposed to suicide that may inform prevention programming.     

Inside the movie roadshow: a critical approach to media events in China

Although face-to-face events starring film professionals have become increasingly popular, they have rarely been studied, especially from the perspective of production. Focusing on the phenomenon of Chinese movie roadshows, this study explores the motivations and techniques used to produce popular media events in the Chinese film industry. Based on expert interviews with 15 media practitioners, the results showed that roadshows are staged as ritualized events that are centered on the performance of a symbolic boundary between “inside” and “outside” the media. Film industry professionals embrace face-to-face communication with audiences and use such events to display sincerity, producing them as a seemingly “unmediated” peek behind the veil of an otherwise hidden world. Moreover, communication on social media is another form of ritualized practice. We conclude that, by thus mediating the “unmediated,” movie roadshows offer an insightful perspective on the machinery of media power in China.