On a Dualization of Graphical Gaussian Models: A Correction Note

Abstract.  We correct two proofs concerning Markov properties for graphs representing marginal independence relations.     

Risk Compensation or Risk Reduction? Seatbelts,State Laws,and Traffic Fatalities*

Objective. The risk compensation hypothesis suggests that drivers enjoying greater safety will drive more recklessly and thereby impose greater risks on nonoccupants. We provide a test of the risk compensation hypothesis in the context of state seatbelt laws and belt use rates. Methods. Fixed‐effects models with policy and demographic variables are estimated using annual state data from 1985 to 2002 to test the effect of seatbelt laws and seatbelt use rates on logged fatality rates for occupants, pedestrians, motorcyclists, and all nonoccupants in separate models. Results. Contrary to the risk compensation hypothesis, the results indicate that both occupants and nonoccupants enjoy greater safety due to state mandatory use laws and increased safety belt use rates. Conclusion. Overall, seatbelt laws and the higher belt use these laws induce do not increase nonoccupant risk exposure. If anything, these laws and the accompanying increase in belt use result in safer driving behavior.     

Mandatory seat belt laws in the states. A study of fatal and severe occupant injuries

This study examines the impact of mandatory seat belt laws on fatal and incapacitating injury rates in the states. Annual data for all 50 states for the period 1975-1991 are used. Pooled time series analysis is employed. The general conclusion that emerges from this analysis is that seat belt laws significantly impact state fatal injury rates. Primary enforcement and all-seat coverage provisions appear to be particularly effective in reducing fatality rates.     

Job Search: A Multidisciplinary Review and Research Agenda

Scholarly interest in job search has grown significantly over the years and can be located in diverse research streams: namely, economics, sociology and industrial/organizational psychology. This paper reviews these bodies of literature and makes a case for integration by proposing a multidisciplinary approach to understanding job‐seeking behaviors. To this end, the paper categorizes the respective literatures on the basis of common themes located in a conceptual multidisciplinary model of job search behaviors and outcomes. This model provides a more focused understanding of the job search literature and how it has developed in the related disciplines. Based on the review and conceptual model presented, the paper draws attention to several key areas for future research to advance the field further.     

Introductory Statistics Textbooks and the GAISE Recommendations

The six recommendations made by the Guidelines for Assessment and Instruction in Statistics Education (GAISE) committee were first communicated in 2005 and more formally in 2010. In this article, 25 introductory statistics textbooks are examined to assess how well these textbooks have incorporated the three GAISE recommendations most relevant to implementation in textbooks (statistical literacy and thinking; use of real data; stress concepts over procedures). The implementation of another recommendation (using technology) is described but not assessed. In general, most textbooks appear to be adopting the GAISE recommendations reasonably well in both exposition and exercises. The textbooks are particularly adept at using real data, using real data well, and promoting statistical literacy. Textbooks are less adept—but still rated reasonably well, in general—at explaining concepts over procedures and promoting statistical thinking. In contrast, few textbooks have easy-usable glossaries of statistical terms to assist with understanding of statistical language and literacy development. Supplementary materials for this article are available online.     

Experiences of homelessness by people seeking asylum in Australia: A review of published and “grey” literature

This review examines the current published and “grey” literature relating to the experiences of homelessness by people seeking asylum within Australia. While many people seeking asylum have experienced homelessness during their flight, inadequate and unaffordable housing are a feature of the settlement experience for a large number of new arrivals to Australia, putting at risk their successful settlement. This study aims to explore the factors influencing access to stable housing. A systematic review of the academic literature and a search of the grey literature identified 11 articles and 20 documents related to homelessness and people seeking asylum in Australia. The academic literature included a variety of methods and approaches to the investigation of the experience of homelessness in Australia. The grey literature was more practice based, including evaluation and research reports, submissions, and newsletters. Findings suggest that experiences of homelessness are multifaceted and have a range of influences, including policy, financial stress, lack of access to education and employment, and a lack of affordable and suitable housing. Any solutions to address homelessness need to be similarly diverse. Discrimination from real estate agents and employers was also identified as a barrier to housing for many people seeking asylum, an issue that will need to be addressed at a systematic level. The lack of research published in the academic literature means that although there may be some programmes or solutions operating in the community, as demonstrated in the grey literature, this information is not being shared beyond organisation websites or subscriber lists, resulting in a lack of coherency or sharing of solutions. This review highlights the need for further attention to the factors influencing homelessness in asylum seekers, the experience of homelessness, and how these can be addressed by government and non-government led strategies and policy development.     

The Importance of Racial Socialization: School‐Based Racial Discrimination and Racial Identity Among African American Adolescent Boys and Girls

This study examined various parental racial socialization messages as mediators between school‐based racial discrimination and racial identity formation over 4 years for African American boys (N = 639) and African American girls (N = 711). Findings indicated that school‐based racial discrimination was associated with racial identity beliefs. For African American boys, behavioral racial socialization messages mediated the relation between school‐based racial discrimination and racial centrality over time. Mediation also resulted for African American girls, but for a different set of race‐related messages (negative messages and racial barriers) and racial identity beliefs. The developmental significance of the findings and implications for future research are discussed.     

Using Bayesian graphical models to model biases in observational studies and to combine multiple sources of data: application to low birth weight and water disinfection by-products

Summary.  Data in the social, behavioural and health sciences frequently come from observational studies instead of controlled experiments. In addition to random errors, observational data typically contain additional sources of uncertainty such as missing values, unmeasured confounders and selection biases. Also, the research question is often different from that which a particular source of data was designed to answer, and so not all relevant variables are measured. As a result, multiple sources of data are often necessary to identify the biases and to inform about different aspects of the research question. Bayesian graphical models provide a coherent way to connect a series of local submodels, based on different data sets, into a global unified analysis. We present a unified modelling framework that will account for multiple biases simultaneously and give more accurate parameter estimates than standard approaches. We illustrate our approach by analysing data from a study of water disinfection by-products and adverse birth outcomes in the UK.     

Long‐Term Contribution of Immigration to Population Renewal in Canada: A Simulation

We analyze the direct and indirect demographic contribution of immigration to the foreign‐origin composition of the Canadian population according to various projection scenarios over a century, from 2006 to 2106. More specifically, we use Statistics Canada's Demosim microsimulation model to assess the long‐term sensitivity to immigration levels and the frequency of mixed unions of the share of immigrants in Canada and of persons who have at least one ancestor who arrived after 2006. The results of the simulations show that the population renewal process through immigration happens at a fast pace in a high immigration and low fertility country such as Canada. Under the scenarios developed, immigrants who entered after 2006 and their descendants could form the majority of the population by 2058 at the earliest and by 2079 at the latest and could represent between 62 percent and 88 percent in 2106. They also show that mixed unions are a key element of the speed at which the changes are likely to occur in the long run.