Can Choice in Welfare States Be Equitable?

Whether choice is fine or dire for the welfare state is a question that cannot be answered theoretically. That is the conclusion of this article, which discusses conditions that must be fulfilled if choice or increased choice are not to be reflected in increased inequality in access to welfare services. The consequences of non-decision and stress in relation to choice are touched upon. The implication of the analysis is that concrete, empirical analysis is important in order to ascertain whether the conditions for ensuring an informed choice without negative impact on equity in modern welfare states can be fulfilled.     

Taking a "Hands On" Approach to Diversity in Higher Education: A Critical-Dialogic Model for Effective Intergroup Interaction

This article reviews divergent empirical evidence on interracial contact. While research on diversity in higher education provides ample evidence for the educational benefits of engaging with diversity in informal interactions or courses, experimental and naturalistic studies in social psychology on interracial interactions reveal a complicated picture, showing what appear to be both positive and negative effects. Rather than addressing the question of whether or not to promote interracial interactions on campus, we present a critical-dialogic model of intergroup dialogue that centers on communication processes as an avenue toward intergroup relationships, understanding, and collaboration. Prior research and preliminary results from a nine-university research collaboration provide strong empirical support for the proposed model. We conclude with program and policy considerations for higher education institutions interested in promoting meaningful intergroup interaction.     

Parameter Orthogonality and Bias Adjustment for Estimating Functions

Abstract.  We consider an extended notion of parameter orthogonality for estimating functions, called nuisance parameter insensitivity, which allows a unified treatment of nuisance parameters for a wide range of methods, including Liang and Zeger's generalized estimating equations. Nuisance parameter insensitivity has several important properties in common with conventional parameter orthogonality, such as the nuisance parameter causing no loss of efficiency for estimating the interest parameter, and a simplified estimation algorithm. We also consider bias adjustment for profile estimating functions, and apply the results to restricted maximum likelihood estimation of dispersion parameters in generalized estimating equations.     

State-space models for multivariate longitudinal data of mixed types

We propose a class of state-space models for multivariate longitudinal data where the components of the response vector may have different distributions. The approach is based on the class of Tweedie exponential dispersion models, which accommodates a wide variety of discrete, continuous and mixed data. The latent process is assumed to be a Markov process, and the observations are conditionally independent given the latent process, over time as well as over the components of the response vector. This provides a fully parametric alternative to the quasilikelihood approach of Liang and Zeger. We estimate the regression parameters for time-varying covariates entering either via the observation model or via the latent process, based on an estimating equation derived from the Kalman smoother. We also consider analysis of residuals from both the observation model and the latent process.     

Expected Survival in the Cox Model

The survival in a group of patients is calculated using a Kaplan–Meier curve and the hypothesis that the survival can be predicted by a specified Cox hazard is studied. This Cox hazard is obtained from a previous study of similar patients. A simple test of the hypothesis is constructed by comparing a suitable average of the individual predicted survival curves with the observed survival. Three averaging procedures are presented; "direct adjusted survival curve", "Bonsel's survival curve" and "expected survival curve". Consistency and asymptotic distribution properties of the comparisons are discussed.     

The U.S. EPA Geographic Information System for Mapping Environmental Releases of Toxic Chemical Release Inventory (TRI) Chemicals

This study characterizes the environmental releases of toxic chemicals of the Toxic Chemical Release Inventory (TRI) in the southeastern United States by using the U.S. Environmental Protection Agency (EPA) Geographic Information System (GIS) to map them. These maps show that the largest quantities of TRI releases in the Southeast are usually near densely populated areas. This GIS mapping approach takes the first steps in defining those areas in the region which may be potential exposure zones and which could be strategic targets for future risk screening efforts in this geographic area.     

The rules of conditional inference: Is there a universal definition of nonformation?

Summary We consider the ideas of sufficiency and ancillarity for parametric models with nuisance parameters, and more generally Barndorff-Nielsen's notion of nonformation. The original four definitions of non-formation, namelyB-,S-,G- andM-nonformation, each cover different types of models. We stress the interpretation of nonformation in terms of the idea of perfect fit. This leads to a new definition of nonformation, calledI-nonformation, which is well suited for inference in exponential families. We also consider Rémon's concept ofL-sufficiency, and a recent extension toL-nonformation, due to Barndorff-Nielsen, which unifies and extendsB-,S- andG- nonformation. We study the relations between these six definitions, and show that they are all special cases ofM-nonformation. All animals are equal, but some animals are more equal than others. From ‘Animal Farm’, by G. Orwell (1945).