An Empirical Study of Statistical Properties of Variance Partition Coefficients for Multi-Level Logistic Regression Models

Partitioning the variance of a response by design levels is challenging for binomial and other discrete outcomes. Goldstein (2003 Goldstein , H. ( 2003 ). Multilevel Statistical Models. 3rd ed . London : Edward Arnold . [Google Scholar]) proposed four definitions for variance partitioning coefficients (VPC) under a two-level logistic regression model. In this study, we explicitly derived formulae for multi-level logistic regression model and subsequently studied the distributional properties of the calculated VPCs. Using simulations and a vegetation dataset, we demonstrated associations between different VPC definitions, the importance of methods for estimating VPCs (by comparing VPC obtained using Laplace and penalized quasilikehood methods), and bivariate dependence between VPCs calculated at different levels. Such an empirical study lends an immediate support to wider applications of VPC in scientific data analysis.     

Taking the longer view: Explaining Multicultural London English and Multicultural Paris French

The article explores the perplexing outcomes of comparative research projects in London and Paris on language change in multilingual areas of the cities populated by large numbers of recent immigrants with very diverse language backgrounds. In London, as in many other northern European cities, language contact on such a large scale has resulted in the emergence of a “multiethnolect”: a repertoire of innovative linguistic forms used by young people of all ethnicities, including monolingual non‐immigrant speakers. In Paris, however, there was no such repertoire. I propose four factors that are necessary for a multiethnolect to emerge and that explain why similar processes of population movement, immigration, and globalization have produced such different linguistic outcomes in London and Paris. These factors remind us that language evolution, like language use, is constrained not only by the social characteristics of individuals but also by the socio‐cultural historical contexts in which individuals live.     

On Tests for Group Variation With a Small to Moderate Number of Groups

This paper considers a family of penalized likelihood score tests for group variation. The tests can be indexed by a measure of degrees of freedom. At one extreme, with degrees of freedom one less than the number of groups, is the usual score test for a fixed effects alternative using indicator variables for the groups, while at the other extreme, in the limit as the degrees of freedom 0, is a test closely related to a score test based on a random effects alternative. Asymptotic power comparisons are made for the tests in the family. As would be expected, different members of the family are more efficient for different alternatives. Generally the tests with smaller degrees of freedom appear to have better power than the standard test for alternatives focusing on differences among the larger groups, and lower power for alternatives focusing on differences among the smaller groups. Simulations indicate the asymptotic approximation to the distribution performs better for the tests with small degrees of freedom.     

Principles for Conduct of Pest Risk Analyses: Report of an Expert Workshop

The North American Free Trade Agreement (NAFTA) and the General Agreement on Tariffs and Trade (GATT) have focused attention on risk assessment of potential insect, weed, and animal pests and diseases of livestock. These risks have traditionally been addressed through quarantine protocols ranging from limits on the geographical areas from which a product may originate, postharvest disinfestation procedures like fumigation, and inspections at points of export and import, to outright bans. To ensure that plant and animal protection measures are not used as nontariff trade barriers, GATT and NAFTA require pest risk analysis (PRA) to support quarantine decisions. The increased emphasis on PRA has spurred multiple efforts at the national and international level to design frameworks for the conduct of these analyses. As approaches to pest risk analysis proliferate, and the importance of the analyses grows, concerns have arisen about the scientific and technical conduct of pest risk analysis. In January of 1997, the Harvard Center for Risk Analysis (HCRA) held an invitation-only workshop in Washington, D.C. to bring experts in risk analysis and pest characterization together to develop general principles for pest risk analysis. Workshop participants examined current frameworks for PRA, discussed strengths and weaknesses of the approaches, and formulated principles, based on years of experience with risk analysis in other setting and knowledge of the issues specific to analysis of pests. The principles developed highlight the both the similarities of pest risk analysis to other forms of risk analysis, and its unique attributes.     

Adolescent Depression and Time Spent with Parents and Siblings

This study examines adolescent depressive symptoms and the quantity and quality of time spent by adolescents with their parents and siblings. We use measures of the quality of relationships with parents and siblings as proxy indicators for the quality of time spent with these social partners. The study emphasizes the salience of parent relationships to adolescent depression. The structural equation models suggest that time spent with parents is indirectly linked with the severity of depressive symptoms via adolescents’ perceptions of how accepting their parents are of them, and the extent to which parents avoid exerting psychological control. We discuss these findings in relation to clinical practice.     

Thirty Years of Lottery Public Health Research: Methodological Strategies and Trends

Cognitive measurement techniques, such as self-reports of behavior and reaction time measures, largely dominate the field of psychological research. It is uncommon for researchers to examine a phenomenon of interest by observing actual behavior within natural settings. To illustrate the existence of this methodological trend for gambling research, this article reviews systematically selected samples of the peer-reviewed literature related to lottery gambling in general and the literature related to pathological gambling and lottery more specifically. The results indicate that self-report surveys dominate the extant lottery literature, and experimental investigations of video lottery terminal gambling supplement those papers. This landscape encourages researchers to expand their methodological approaches to the study of lottery gambling. Currently, we know more about what research participants tell us they do with respect to lottery gambling than we do about their real-life lottery gambling behavior.