Automating and evaluating reversible jump MCMC proposal distributions

The reversible jump Markov chain Monte Carlo (MCMC) sampler (Green in Biometrika 82:711–732, 1995) has become an invaluable device for Bayesian practitioners. However, the primary difficulty with the sampler lies with the efficient construction of transitions between competing models of possibly differing dimensionality and interpretation. We propose the use of a marginal density estimator to construct between-model proposal distributions. This provides both a step towards black-box simulation for reversible jump samplers, and a tool to examine the utility of common between-model mapping strategies. We compare the performance of our approach to well established alternatives in both time series and mixture model examples.     

Ecosystem resilience, specialized adaptation and population decline: A modern Malthusian theory

The purpose of this article is to construct a theoretical framework characterizing the interactions among economic development, ecosystem equilibrium and possible population decline, and to discuss the population dynamics in the very long run. In our framework, economic activities bridge population and environment. On the one hand, human beings reform the environment through economic activities; on the other hand, economic activities decrease environmental resilience and increase the possibility of an environmental change in a discontinuous and irreversible pattern, as described in Arrow et al. (1995). Furthermore, a highly developed economy also causes over-specialization of human adaptation, which tends to exaggerate the impact of an environmental change on human population size. Received: 19 January 1999/Accepted: 3 July 1999     

DISCRIMINATION, WOMEN, AND WORK: Processes and Variations by Race and Class

Research on gender and workplace stratification has made clear that persistent employment, wage, and mobility gaps exist, and that discrimination at organizational and interactional levels is playing a role. Few studies, however, have been able to directly capture processes involved. In this article, we draw on unique qualitative and quantitative data pertaining to verified cases of workplace sex and race discrimination (1988 to 2003), and analyze the discriminatory experiences of African-American and white women across various occupational statuses. Notable are high levels of discriminatory firing for both groups, but higher instances of race-based promotional discrimination for black women—a pattern partially linked to their disparate concentration in sex-segregated workplaces and in positions of lower occupational prestige. Our qualitative immersion into case materials reveals influential mechanisms and employer justifications, unique manifestations of differential treatment on the job, and the use of "soft skill" criteria in gatekeeper decision making. We conclude by discussing important dimensions of workplace discrimination for women, variations by social class and race status, and how complexities of status matter for what women experience and gatekeeper behavior.     

Urbanization-related distribution patterns and habitat-use by the marine mesopredator,giant Pacific octopus (<Emphasis Type="Italic">Enteroctopus dofleini</Emphasis>)

Urbanization is a process that heavily alters marine and terrestrial environments, though terrestrial urban ecosystems have been studied far more intensively. Terrestrial studies suggest that urbanization can facilitate mesopredators by enhancing food and shelter resources and reducing predation pressure from apex consumers. This in turn has considerable consequences for ecological communities. We evaluated spatial distribution patterns and habitat-use of the marine mesopredator, giant Pacific octopus (Enteroctopus dofleini), relative to terrestrial urbanization intensity in Puget Sound, Washington, USA. Using field surveys and citizen-contributed data for E. dofleini, we examined whether: (1) Distribution was related to urbanization, (2) Abundance was related to the extent of benthic anthropogenic debris, and (3) Diet differed as a function of urbanization and den cover. Our results suggest that urbanization impacts may differ with depth. Mixed-effects logistic regression model estimates for the probability of occurrence increased with urbanization in deep-water (> 24 m), and decreased with urbanization in shallow water (< 18 m). Accompanying field surveys indicated that E. dofleini abundance was correlated with the number of benthic anthropogenic debris items, and that E. dofleini diets were not affected by urbanization intensity or den cover. Though E. dofleini may be synanthropic within certain urban environments, the mechanisms driving this pattern likely differ from those affecting common urban mesopredators on land, with den provisioning from man-made structures being more important than altered food resources.     

Simultaneous decomposition of the variance by sources and subgroups – new insights

There are two types of decompositions: of linear combinations of random variables into contributions of individual variables (sources) and associations between them, and of populations into contributions of their subpopulations. Simultaneous treatment of the two types is called for, which takes into account the correlations between sources within subpopulations and between subpopulation means. The expected values of the subcomponents are derived and their sensitivity to correlations among sources within groups and among source group means is conducted. An example is provided, in which the correlations contribute 20--25% to total variability. This additional information is hidden when decompositions are not simultaneous.     

Racial/Ethnic Minority Vocational Research Trends: An 11‐Year Update

This study extends Flores et al.'s ( 2006 ) 36‐year analysis of racial/ethnic minority (REM) career research to identify recent trends in choice of topics and leading individual and institutional contributors. The authors identified 166 articles on REM career research published from 2005 to 2015 in the Journal of Vocational Behavior, The Career Development Quarterly, the Journal of Career Assessment, and the Journal of Career Development. Of these studies, 92% were empirical, with more than three quarters of these using quantitative rather than qualitative methodology. Most frequently, the empirical studies (n = 153) were based on samples of high school (30.7%) or undergraduate (34.6%) students. The authors discuss the implications of their findings and suggest ways to expand REM career research in the future.     

NGO Strategies in an Authoritarian Context,and Their Implications for Citizenship: The Case of the People’s Republic of China

This study argues that different cities in China have different resource environments available for NGOs. Organizations react to these resource environments by constructing appropriate resource strategies, which in turn shape the characteristics and structures of the NGOs of that city. It further examines how these characteristics and structures influence the construction and performance of citizenship in an authoritarian environment. Specifically, some types of NGOs encourage Chinese citizens to be passive, while others offer a model for people to actively engage with social issues. This is aptly demonstrated in an analysis of NGOs operating across four cities—Beijing, Shanghai, Kunming, and Nanjing—which reveals three different types of resource environments and behavioral models for NGOs. We subsequently discuss the implications of each model for citizen engagement.     

Employee communication,job engagement,and organizational commitment: A study of members of the Millennial Generation

The purpose of this study was to explore the relationship between job engagement and two key components of employee-organization relationships (EOR). Findings from a survey of members of the Millennial Generation (N = 539) in the United States indicate that job engagement mediates the relationship between employee communication and organizational commitment. It is concluded that when employees are engaged in their work, their commitment to the organization is strengthened and the likelihood of them leaving the organization decreases. Furthermore, an argument is made in light of the study’s findings that engagement and commitment work in concert to strengthen EORs overall. To foster engagement, organizations should remove obstacles to internal information flow and provide ongoing feedback to employees about individual and organizational issues.     

Indigenous Knowledge,Beliefs, and Cultural Practices for Children and Families in Nigeria

This study examined the indigenous cultural practices that impact the well-being of children and families at five sites in Nigeria. Fifteen community leaders participated in semi-structured interviews, and 78 community members participated in focus group discussions in their communities. Responses were analyzed using a grounded theory and thematic analysis approach. Three cultural practices are discussed: the naming ceremony of the child, the use of Oríkì, and the care of children and family by relatives. Overall, the cultural practices largely reflected the indigenous knowledge and beliefs of the local context. Implications for social work are discussed.