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.     

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.     

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.     

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.     

Treatment Utilization Among Metropolitan and Nonmetropolitan Participants of Corrections-Based Substance Abuse Programs Reentering the Community

ABSTRACT

This study examines differences in drug use and recidivism outcomes at 12 months postrelease from jail or prison as a function of geographic location and treatment utilization. Participants (N= 700) were previously enrolled in drug treatment during the last 6 to 9 months of their incarceration and were released to the community on either parole or serve-out. Findings from this study indicated that offenders returning to metropolitan areas reported more use of community treatment services following release than offenders in nonmetropolitan areas. Although offenders in both metropolitan and nonmetropolitan areas who reported community treatment following release were less likely to be reincarcerated, community treatment utilization was not a significant correlate of relapse. Findings are discussed, and future directions include favorable outcomes when community treatment is utilized.     

The Meaning of Gender While Aging With Paralytic Polio

The purpose of this article is to report the influence of gender on aging with childhood onset paralytic polio. The hermeneutic phenomenological exploration of gender was done using multiple qualitative interviews with 25 women, age 55 to 75 years of age, who had polio since before 14 years of age. We noted three themes: (a) the movement of her body, (b) integrating body and gender, and (c) gender discrepancies. Findings are discussed in the context of gendered expectations and the women's bodies.     

Comparison of household-survey estimates with projections of mortality and orphan numbers in sub-Saharan Africa in the era of HIV/AIDS

The United Nations publishes estimates of HIV prevalence, AIDS mortality, and orphan numbers for all countries of the world. It is important to assess the validity of these model-based estimates since they underpin much policy concerned with care and prevention. Household surveys that ask questions about the survival of children's parents (orphanhood) offer an independent source of data with which these estimates can be compared. Survey estimates of maternal and paternal orphans are significantly lower than model estimates for 40 surveys in 36 countries of sub-Saharan Africa (p < 0.001, p = 0.002). This is probably because adult mortality from causes other than AIDS is lower than assumed in the models, although under-reporting of orphanhood in surveys may also play a role. Reducing adult mortality from causes other than AIDS brings the model estimates into close agreement with the surveys. This suggests that the fraction of orphans attributable to AIDS is greater than estimated previously.