Assessing the performance of variational methods for mixed logistic regression models

We present a variational estimation method for the mixed logistic regression model. The method is based on a lower bound approximation of the logistic function [Jaakkola, J.S. and Jordan, M.I., 2000, Bayesian parameter estimation via variational methods. Statistics & Computing, 10, 25–37.]. Based on the approximation, an EM algorithm can be derived that results in a considerable simplification of the maximization problem in that it does not require the numerical evaluation of integrals over the random effects. We assess the performance of the variational method for the mixed logistic regression model in a simulation study and an empirical data example, and compare it to Laplace's method. The results indicate that the variational method is a viable choice for estimating the fixed effects of the mixed logistic regression model under the condition that the number of outcomes within each cluster is sufficiently high.     

Early-life mortality clustering in families: A literature review

Research on early-life mortality in contemporary and historical populations has shown that infant and child mortality tend to cluster in a limited number of high-mortality families, a phenomenon known as ‘mortality clustering’. This paper is the first to review the literature on the role of the family in early-life mortality. Contemporary results, methodological and theoretical shortfalls, recent developments, and opportunities for future research are all discussed in this review. Four methodological approaches are distinguished: those based on sibling deaths, mother heterogeneity, thresholds, and excess deaths in populations. It has become clear from research to date that the death of an older child harms the survival chances of younger children in that family, and that fertility behaviour, earlier stillbirths, remarriages, and socio-economic status all explain mortality clustering to some extent.     

Exploring narratives of education: disabled young people’s experiences of educational institutions in Ghana

Disabled young people in many low and middle-income countries experience significant levels of educational exclusion due to disabling social and physical environments and are more likely to be illiterate than their non-disabled peers. Most social sciences and development literature, however, tends to homogenise the educational trajectories of disabled young people and focuses predominantly on the perspectives of educationalists, development experts and carers in assessing educational needs and institutions. Consequently, the experiences of young people across multiple categories of social difference, and their agency in shaping their own educational trajectories, remain largely unknown. This article contributes to filling this gap by exploring the educational narratives of young people with different impairments in mainstream, special and integrated schools in Ghana. The article shows how exploring individual narratives provides new insights into the educational needs of and ‘appropriate’ education for disabled young people in the Global South.     

HPV vaccine acceptance among a sample of Southern men who have sex with men: A comparison of younger and older men

Objectives: Do short, online educational messages about the human papillomavirus (HPV) influence younger and older men who have sex with men (MSM) differently? Second, what are the HPV knowledge levels and risk perceptions of Southern MSM living outside of major metropolitan areas? Methods: This study draws on participants who completed an anonymous online survey asking about their knowledge, risk assessment, and vaccine acceptance regarding HPV. Results: Knowledge about HPV was low among the MSM in this study. After reading a one-page information intervention, vaccine acceptability increased by a statistically significant amount among both a Younger and Older cohort but risk perception only increased among the younger respondents. Single men regardless of age cohort reported sharper increases in perceived risk after the intervention, but relationship status did not produce significant differences in vaccine acceptability. Conclusion: Online, brief interventions may be effective means of increasing motivation to vaccinate among Southern MSM.     

A decade of changes: Within-group analysis of LGBTQ individuals' perceptions of their community context and the relevance for social service providers

The previous decade has seen a drastic shift in the social environment for lesbian, gay, bisexual, transgender, and queer (LGBTQ) people. It is not surprising then to find that the perceived “best” and “worst” aspects of life for nonmetropolitan LGBTQ individuals have also changed. We use data from two cohorts of the Rainbow Illinois survey to examine differences between responses in 2000 and 2011. Furthermore, we examine demographic differences in the perception of what is “best” and “worst” among the 2011 cohort. Results suggest that although the general social climate has improved for some, it remains problematic for others. Implications for social service providers are thoroughly discussed.     

Scanner Data and the Treatment of Quality Change in Nonrevisable Price Indexes

The recently developed rolling year GEKS procedure makes maximum use of all matches in the data to construct nonrevisable price indexes that are approximately free from chain drift. A potential weakness is that unmatched items are ignored. In this article we use imputation Törnqvist price indexes as inputs into the rolling year GEKS procedure. These indexes account for quality changes by imputing the “missing prices” associated with new and disappearing items. Three imputation methods are discussed. The first method makes explicit imputations using a hedonic regression model which is estimated for each time period. The other two methods make implicit imputations; they are based on time dummy hedonic and time-product dummy regression models and are estimated on bilateral pooled data. We present empirical evidence for New Zealand from scanner data on eight consumer electronics products and find that accounting for quality change can make a substantial difference.     

Estimating the population proportion in modified ranked set sampling methods

In this paper, proportion estimators and associated variance estimators are proposed for a binary variable with a concomitant variable based on modified ranked set sampling methods, which are extreme ranked set sampling (ERSS), median ranked set sampling (MRSS), percentile ranked set sampling (Per-RSS) and L ranked set sampling (LRSS) methods. The Monte Carlo simulation study is performed to compare the performance of the estimators based on bias, mean squared error, and relative efficiency for different levels of correlation coefficient, set and cycle sizes under normal and log-normal distributions. Moreover, the study is supported with real data application.     

Observational sketching as method

This paper explores the potential of observational sketching as a social science research tool, informed by our own recent experiments with observational sketching techniques and approaches. We first outline the historical roots of academic sketching and note a recent resurgence of interest in sketching in certain disciplines. We then introduce our own explorations in sketching as method, based on a year-long collaboration between an observational artist and a group of qualitative researchers with interests in creative methods. The paper outlines some of the lessons we learnt from our partnership, focusing on three themes: (i) ‘sketchiness’; (ii) ‘concentrated seeing’ and (iii) sketching as interaction. We conclude that observational sketching generates a refreshingly different form of visual data which has considerable potential to be used as a complement to other methods, including as a participatory method and as a useful tool for thinking.     

Population aging and long-term care policies in the Gulf region: a case study of Oman

Population aging is a phenomenon occurring across the globe including in countries traditionally exhibiting population dividends and “youth bulges.” The Gulf Corporation Council countries are no exception as they currently experience a process of population aging, albeit at a different stage from many developed countries. However, due to historically high fertility rates and fast-paced epidemiological transition, some of these countries will experience population aging at a higher pace than what has been observed in Europe and the United States. This article reviews recent developments in long-term care policies in the Gulf region with a focus on Oman as an example of a high-income Arab country that is experiencing population aging while still being governed by traditional family aged-care norms. Utilizing existing data and published research complemented by policy analysis and field visits, we analyze the process of population aging in Oman and neighboring countries and its policy implications.