Model determination for categorical data with factor level merging

Summary.  We deal with contingency table data that are used to examine the relationships between a set of categorical variables or factors. We assume that such relationships can be adequately described by the cond`itional independence structure that is imposed by an undirected graphical model. If the contingency table is large, a desirable simplified interpretation can be achieved by combining some categories, or levels, of the factors. We introduce conditions under which such an operation does not alter the Markov properties of the graph. Implementation of these conditions leads to Bayesian model uncertainty procedures based on reversible jump Markov chain Monte Carlo methods. The methodology is illustrated on a 2×3×4 and up to a 4×5×5×2×2 contingency table.     

Taking the Lab to the Field: Monitoring Reproductive Hormones in Population Research

The incorporation of biological measures in social science research allows for the development of robust models, with greater explanatory power. By analyzing the underlying proximate causes of fertility and mortality, biodemographers have been able to model demographic patterns more accurately. Recent technological advances are making possible the analysis of biological samples collected using minimally invasive methods. Methods and techniques are discussed that can be used for estimating hormonal, particularly reproductive hormone, levels in large‐scale population studies in which thousands of samples could be collected. Sample collection methods and techniques reviewed include blood spots, urine samples, and saliva samples. The collection of biological samples is associated with serious ethical concerns. The article discusses the issue of asymmetries in technology between developing and developed countries, emphasizing the need for capacity building and information transfer. Illustrative contributions of biological data are presented.     

Risk‐Taking and the Media

In recent years, media formats with risk‐glorifying content, such as video games that simulate illegal street racing (“bang and crash” games), films about extreme sports, and risky stunts have emerged as top sellers of the media industry. A variety of recent studies conducted by several researchers revealed that exposure to risk‐glorifying media content (e.g., video games that simulate reckless driving, smoking and drinking in movies, or depictions that glorify extreme sports) increases the likelihood that recipients will show increased levels of risk‐taking inclinations and behaviors. The present article (1) reviews the latest research on the detrimental impact of risk‐glorifying media on risk‐taking inclinations (cognitions, emotions, behaviors), (2) puts these findings in the theoretical context of recent sociocognitive models on media effects, and (3) makes suggestions to science and policymakers on how to deal with these effects in the future.     

Religion und Bildungserfolg im Migrationskontext – Theoretische Argumente,empirische Befunde und offene Fragen

Religion has received extensive attention as a factor influencing immigrants’ integration. This paper examines the role of religion in explaining ethnic educational inequalities in Germany. Due to a general lack of research in this field, the paper provides an overview of existing empirical findings, specifies theoretical arguments on how religious affiliation, belief and participation possibly affect educational achievement among children of immigrants. Using data from the first wave of the “Children of Immigrants Longitudinal Survey in four European Countries” collected in 2010/11 the paper tests key arguments on the influence of religion on the educational attainment among 14-year-old immigrant and non-immigrant students at German schools. Compared to other religious groups, Muslims display lower rates of educational achievement. However, this can be largely explained by their social background and is independent from their levels of individual religiosity. Interestingly, individual religiosity has a positive effect on the educational achievement among Protestant students, whether with or without a migration background.     

A Multifactorial Risk Prioritization Framework for Foodborne Pathogens

We develop a prioritization framework for foodborne risks that considers public health impact as well as three other factors (market impact, consumer risk acceptance and perception, and social sensitivity). Canadian case studies are presented for six pathogen‐food combinations: Campylobacter spp. in chicken; Salmonella spp. in chicken and spinach; Escherichia coli O157 in spinach and beef; and Listeria monocytogenes in ready‐to‐eat meats. Public health impact is measured by disability‐adjusted life years and the cost of illness. Market impact is quantified by the economic importance of the domestic market. Likert‐type scales are used to capture consumer perception and acceptance of risk and social sensitivity to impacts on vulnerable consumer groups and industries. Risk ranking is facilitated through the development of a knowledge database presented in the format of info cards and the use of multicriteria decision analysis (MCDA) to aggregate the four factors. Three scenarios representing different stakeholders illustrate the use of MCDA to arrive at rankings of pathogen‐food combinations that reflect different criteria weights. The framework provides a flexible instrument to support policymakers in complex risk prioritization decision making when different stakeholder groups are involved and when multiple pathogen‐food combinations are compared.     

Nothing Matters

This essay reads Miller reading literature and zero, zero in literature, tracing how a doubling at the heart of zero is echoed in Miller's work. Miller's fascination and engagement with literature as otherness invokes the ambiguity of the sign O, sharing its figure with a figure that isn't a figure, impossibly at once letter and numeral, now converging in Miller's text on zero in literature. Literature, like zero, like the lover, like the Other, incessantly invites analysis only to elude understanding. Nothing matters because it is a place of slippage, playfully unsettling our most deeply ingrained beliefs.     

Eco-efficient supply chain networks: development of a design framework and application to a real case study

This paper presents a supply chain network design framework that is based on multi-objective mathematical programming and that can identify ‘eco-efficient’ configuration alternatives that are both efficient and ecologically sound. This work is original in that it encompasses the environmental impact of both transportation and warehousing activities. We apply the proposed framework to a real-life case study (i.e. Lindt & Sprüngli) for the distribution of chocolate products. The results show that cost-driven network optimisation may lead to beneficial effects for the environment and that a minor increase in distribution costs can be offset by a major improvement in environmental performance. This paper contributes to the body of knowledge on eco-efficient supply chain design and closes the missing link between model-based methods and empirical applied research. It also generates insights into the growing debate on the trade-off between the economic and environmental performance of supply chains, supporting organisations in the eco-efficient configuration of their supply chains.     

Effects of receipt of Social Security retirement benefits on older women’s employment

Labor force participation of women has declined since 1999; however, labor force participation of women 62+ has increased. The 2000–2006 waves of Health and Retirement Study (HRS) data, the initial years of the continuing upward trajectory, were used to test the effects of receipt of Social Security retirement benefits on older women’s employment. The models tested: (a) the effect of receipt of Social Security retirement benefits on whether employed; and (b) for women receiving Social Security retirement benefits, the effect of age elected receipt of benefits on whether employed. Both models included the effects of human capital characteristics and income sources. Receipt of Social Security benefits, pension income, and current age reduced the likelihood of employment; while educational level, good to excellent health, and nonmarried marital status increased the likelihood of employment. The older the woman was when she elected Social Security benefits, the more likely she was to be employed.