Slice sampling mixture models

We propose a more efficient version of the slice sampler for Dirichlet process mixture models described by Walker (Commun. Stat., Simul. Comput. 36:45–54, 2007). This new sampler allows for the fitting of infinite mixture models with a wide-range of prior specifications. To illustrate this flexibility we consider priors defined through infinite sequences of independent positive random variables. Two applications are considered: density estimation using mixture models and hazard function estimation. In each case we show how the slice efficient sampler can be applied to make inference in the models. In the mixture case, two submodels are studied in detail. The first one assumes that the positive random variables are Gamma distributed and the second assumes that they are inverse-Gaussian distributed. Both priors have two hyperparameters and we consider their effect on the prior distribution of the number of occupied clusters in a sample. Extensive computational comparisons with alternative “conditional” simulation techniques for mixture models using the standard Dirichlet process prior and our new priors are made. The properties of the new priors are illustrated on a density estimation problem.     

Addressing common forms of child maltreatment: evidence‐informed interventions and gaps in current knowledge

This paper reviews interventions for preventing the occurrence and recurrence of major types of child maltreatment. We begin with an overview of the challenges of establishing evidence‐based interventions to prevent child abuse and neglect in many countries, and underscore the importance of this need with child maltreatment incidence rates in the USA, and how much each type and subtype contribute to child out‐of‐home placement. Next, we identify the well‐supported, supported and promising interventions for each child maltreatment type and subtype, according to their level of research evidence using an evidence‐based clearing house. The paper closes with a discussion of the implications for practice, evaluation, policy and agency management, including intervention knowledge gaps that showcase areas that need additional practice research.     

文化、自我建构与中国人的休闲

Markus和Kitayama提出了独立型自我建构与互依型自我建构概念:独立型自我个体崇尚彰显自我价值和与众不同,愿意把自己从环境和他人中脱离出来;而互依型自我建构个体重视人与人之间的关系,密切关注他人的需求与感受,愿意把自己融入环境和他人关系中。自我建构概念对理解中国人的休闲非常有益。第一,互依型自我建构特征影响着中国人的休闲认知,大部分中国人认为参加休闲活动可以增进家人感情和促进人际和谐,该认知进一步影响了休闲活动选择和休闲制约。第二,互依型自我建构特征还影响着中国人的休闲情绪。中国人喜欢温和情绪体验,与西方人相比更喜欢静态的休闲活动。第三,互依型自我建构特征也影响着中国人的休闲动机。西方学者认为休闲的核心特征是自由选择和自主性。但大量研究表明,它们最适于西方独立型自我建构个体,对处于东方文化中的互依型自我建构个体来说,人际关系和归属感比自由选择更重要。     

The Effect of Expected Income on Individual Migration Decisions

This paper develops a tractable econometric model of optimal migration, focusing on expected income as the main economic influence on migration. The model improves on previous work in two respects: it covers optimal sequences of location decisions (rather than a single once‐for‐all choice) and it allows for many alternative location choices. The model is estimated using panel data from the National Longitudinal Survey of Youth on white males with a high‐school education. Our main conclusion is that interstate migration decisions are influenced to a substantial extent by income prospects. The results suggest that the link between income and migration decisions is driven both by geographic differences in mean wages and by a tendency to move in search of a better locational match when the income realization in the current location is unfavorable.     

A decision-theoretical view of default priors

In this article, we outline a simple and intuitively appealing procedure to derive default priors. The main idea is to regard the choice of such a prior as a formal Bayesian decision problem. We also discuss Jeffreys prior and more generally the reference prior of Bernardo (J R Stat Soc B 41:113–147, 1979) from this standpoint.     

Positive Changes in Perceptions and Selections of Healthful Foods by College Students After a Short-Term Point-of-Selection Intervention at a Dining Hall

Abstract

Objective: Determine the effects of a short-term, multi-faceted, point-of-selection intervention on college students’ perceptions and selection of 10 targeted healthful foods in a university dining hall and changes in their self-reported overall eating behaviors. Participants: 104 college students, (age 18–23) completed pre-I and post-I surveys. Methods: Pre-survey collected at dining hall in April 2007, followed by 3-week intervention then post-survey collected via email. Healthy choice indicators, large signs, table tents, flyers and colorful photographs with “benefit-based messages” promoted targeted foods. Response rate to both surveys was 38%. Results: Significantly more participants reported that healthful choices were clearly identified in the dining hall after the intervention. Over 20% of participants reported becoming more aware of healthful food choices in the dining hall after the intervention. Significant increases in self-reported intake were reported for cottage cheese and low-fat salad dressing, with a trend toward increased consumption of fresh fruit. Seven of the 14 assessed eating behaviors had significant changes in the desired direction. Increased awareness of healthful foods was the top reason for self-reported changes in overall eating behaviors. Conclusion: Short-term, multi-faceted, point-of-selection marketing of healthful foods in university dining halls may be beneficial for improving college students’ perceptions and selections of targeted healthful foods in the dining hall and may improve overall eating behaviors of college students.     

Is professional gambling a directly unproductive profit‐seeking (dup) activity?

Abstract

Research on the economic effects of gambling is still in its infancy and there have been numerous misconceptions propagated in the literature. For example, recently in the Journal of Economic Perspectives (and elsewhere in previous years) it was argued that gambling might, in some cases, constitute a directly unproductive profit‐seeking activity. This paper explains why gambling (even by professional gamblers) cannot legitimately be considered a DUP activity.     

Military Invasion and Women's Political Representation

The bodies produced by the violent practice of suicide bombing are a source of horror and disgust. They are, in feminist psychoanalyst Julia Kristeva's concept, abject: that which defies borders and is expelled to create the self. As ‘abject bodies’, suicide bombers' bodies frustrate attempts at calculation and rational control of security risks, and, in their mutilated flesh, expose as unstable the idea of the body as a whole with clearly defined boundaries between inside and outside. Female suicide bombers, whose bodies are already considered ‘abject’, produce a politics of the body that exceeds narratives of victimhood, and whose very monstrosity symbolically threatens the foundations of the nation-state. Attempts at constructing subjects out of the mutilated bodily remains of victims and perpetrators of suicide bombings are key practices in the production of the state and gendered subjects. The practice of suicide bombing and efforts to recover and resignify bodies reveals how power molds and constitutes the border of the body and state simultaneously. The explosive body of the suicide bomber thus has destabilizing effects beyond the motivations of its perpetrators and exposes the political work necessary to maintain the illusion of secure, bounded bodies and states.     

Family of Origin,Race/Ethnicity,and Socioeconomic Attainment: Genotype and Intraindividual Processes

Previous research has mainly focused on the persistent direct influence of early life contexts on young adult socioeconomic attainment, and less is known about intraindividual processes that are responsible for this persistent influence. The present study, using genetically informed longitudinal, prospective data from a nationally representative sample (Add Health), attempted to fill this gap by adding three important findings to the literature: (a) Adolescents experiencing adverse family contexts during childhood and early adolescence showed lower socioeconomic attainment in early adulthood than adolescents from less adverse family contexts, (b) adolescent academic and cognitive competencies and psychological vulnerabilities partially mediated these persistent influences, and (c) individual cumulative genetic characteristics additively and interactively influenced adolescent competencies and vulnerabilities as well as young adult socioeconomic attainment. The results demonstrate that although substantial continuity exists in early adversities, individual genetic variability is a factor that influences individuals' response to early socioeconomic conditions.