Nonparametric empirical Bayes for the Dirichlet process mixture model

The Dirichlet process prior allows flexible nonparametric mixture modeling. The number of mixture components is not specified in advance and can grow as new data arrive. However, analyses based on the Dirichlet process prior are sensitive to the choice of the parameters, including an infinite-dimensional distributional parameter G ₀. Most previous applications have either fixed G ₀ as a member of a parametric family or treated G ₀ in a Bayesian fashion, using parametric prior specifications. In contrast, we have developed an adaptive nonparametric method for constructing smooth estimates of G ₀. We combine this method with a technique for estimating α, the other Dirichlet process parameter, that is inspired by an existing characterization of its maximum-likelihood estimator. Together, these estimation procedures yield a flexible empirical Bayes treatment of Dirichlet process mixtures. Such a treatment is useful in situations where smooth point estimates of G ₀ are of intrinsic interest, or where the structure of G ₀ cannot be conveniently modeled with the usual parametric prior families. Analysis of simulated and real-world datasets illustrates the robustness of this approach.     

Nature and social work pedagogy: How U.S. social work educators are integrating issues of the natural environment into their teaching

ABSTRACT

The article presents a study of how U.S. social work educators are including discussion, exercises, readings, and other pedagogical approaches to the natural environment into their classrooms. The findings are part of a larger, naturalistic study that gathered data using a semi-structured interview format. The three major themes that emerged were human behavior theory, ecological and environmental justice, and environmental sustainability. The participants are introducing issues of the natural environment using varied pedagogical techniques including readings, in-class discussions and exercises, service learning, assignments, including written and practical work, research, self-awareness exercises, and class facilitation. Questions for further investigation of social work and the natural environment are included.     

Probabilistic linear solvers: a unifying view

Statistics and Computing - Several recent works have developed a new, probabilistic interpretation for numerical algorithms solving linear systems in which the solution is inferred in a Bayesian...     

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.     

THE USE OF CHILD-CENTERED PLAY THERAPY AND FILIAL THERAPY WITH HEAD START FAMILIES: A BRIEF REPORT

Play therapy and filial therapy show promise as effective ways to provide direct services to Head Start, addressing the needs of the children, the families, and the Head Start teachers and staff. This paper examines the utility of play and filial therapies for the Head Start population, presents a systemic explanation for the benefit of filial therapy, and provides a case example for illustration.     

The Association of Knowledge with Concern About Global Warming: Trusted Information Sources Shape Public Thinking

During the last decade, a great deal of news media attention has focused on informing the American public about scientific findings on global warming (GW). Has learning this sort of information led the American public to become more concerned about GW? Using data from two surveys of nationally representative samples of American adults, this article shows that the relation between self‐reported knowledge and concern about GW is more complex than what previous research has suggested. Among people who trust scientists to provide reliable information about the environment and among Democrats and Independents, increased knowledge has been associated with increased concern. But among people who are skeptical about scientists and among Republicans more knowledge was generally not associated with greater concern. The association of knowledge with concern among Democrats and Independents who trust scientists was mediated by perceptions of consensus among scientists about GW's existence and by perceptions that humans are a principal cause of GW. Moreover, additional analyses of panel survey data produced findings consistent with the notion that more knowledge yields more concern among Democrats and Independents, but not among Republicans. Thus, when studying the relation of knowledge and concern, it is important to take into account the content of the information that different types of people acquire and choose to rely upon.     

Has the Nordic Welfare Model Been Transformed?

The Nordic welfare model is undergoing a fundamental transformation. Using Denmark we show how a universal welfare state model is gradually being transformed into an emergent multi‐tiered welfare state. Whereas the Danish pension system's having become multi‐tiered in the 1990s, with private schemes – collective and individual – supplementing public schemes is well documented, scant attention has focused on more recent developments in other areas of the welfare state. This article shows how the multi‐tiered welfare state spread in the 2000s to policies for families, the unemployed and the sick. Although Denmark still offers universal coverage in core welfare state areas, the increased use of occupational and fiscal welfare as well as changes in public schemes has gradually transformed the nation into a multi‐tiered welfare state that is more dualistic and individualistic, with participation in the labour market becoming still more important for entitlement to benefits. These profound changes have taken place in such a way that although core characteristics are still in place, new structures and understandings of the welfare state are also developing. Thus classical typologies need revision, so that they include more focus on this combination of universality and institutional attachment to the labour market. Moreover, measures of what welfare comprises should include not only public but also private elements.     

Blind‐sided by Basics: three perspectives on income management in an Aboriginal community in the Northern Territory

Income management was introduced into the Northern Territory in 2007. Despite much rhetoric around evidence based policy making and constant reviewing of income management, there has been little grounded research about Aboriginal responses at the community level to this new institution. In this article I report on the operations of income management from a longer term perspective, working with Kuninjku people and retail outlets in the Maningrida region in Arnhem Land. My argument is that from a local perspective income management is just one of a suite of new measures that have been introduced to alter the norms and values of people to correlate more closely with Australian mainstream norms. This view is based on participant observation rather than direct questioning. Income management is a low priority issue for the Kuninjku people in the current policy maelstrom that seeks to shift policy from ‘self determination’ back to a form of assimilation now heavily influenced by a neoliberal ideological agenda. Local responses vary from indifferent acceptance to resistance. I ponder the crucial policy question, how can we allow substantial financial resources to be squandered in unhelpful income management when they could be deployed productively to enhance wellbeing for Indigenous Australians?