Properties of the bridge sampler with a focus on splitting the MCMC sample

Computation of normalizing constants is a fundamental mathematical problem in various disciplines, particularly in Bayesian model selection problems. A sampling-based technique known as bridge sampling (Meng and Wong in Stat Sin 6(4):831–860, 1996) has been found to produce accurate estimates of normalizing constants and is shown to possess good asymptotic properties. For small to moderate sample sizes (as in situations with limited computational resources), we demonstrate that the (optimal) bridge sampler produces biased estimates. Specifically, when one density (we denote as $$p_2$$) is constructed to be close to the target density (we denote as $$p_1$$) using method of moments, our simulation-based results indicate that the correlation-induced bias through the moment-matching procedure is non-negligible. More crucially, the bias amplifies as the dimensionality of the problem increases. Thus, a series of theoretical as well as empirical investigations is carried out to identify the nature and origin of the bias. We then examine the effect of sample size allocation on the accuracy of bridge sampling estimates and discovered that one possibility of reducing both the bias and standard error with a small increase in computational effort is by drawing extra samples from the moment-matched density $$p_2$$ (which we assume easy to sample from), provided that the evaluation of $$p_1$$ is not too expensive. We proceed to show how the simple adaptive approach we termed “splitting” manages to alleviate the correlation-induced bias at the expense of a higher standard error, irrespective of the dimensionality involved. We also slightly modified the strategy suggested by Wang et al. (Warp bridge sampling: the next generation, Preprint, 2019. arXiv:1609.07690) to address the issue of the increase in standard error due to splitting, which is later generalized to further improve the efficiency. We conclude the paper by offering our insights of the application of a combination of these adaptive methods to improve the accuracy of bridge sampling estimates in Bayesian applications (where posterior samples are typically expensive to generate) based on the preceding investigations, with an application to a practical example.     

Mobile Phone Usage Preferences: The Contributing Factors of Personality,Social Anxiety and Loneliness

Psychological factors and social relationships are important components that influence an individual’s communication style. This paper aims to examine the association of personality factors, social anxiety (SA) and loneliness with mobile phone (MP) usage preferences on the basis of voice calling and text messaging. Malaysian MP users (N = 187) completed four questionnaires (Mobile Phone Usage Questionnaire, Big Five Inventory, Interaction Anxiousness Scale and UCLA Loneliness Scale) on paper or online via a web-link. Multiple regression analyses revealed that personality, SA and loneliness broadly predicted preferences for voice calling or text messaging. Further analyses examining the predictability of time spent on voice calls/text messaging and number of people called/exchanged text messages also revealed some significant findings in regards to the openness-to-experience personality dimension, loneliness and SA. The findings of this research have important implications to tailoring the delivery of psychological services to individuals diagnosed with chronic loneliness and SA.     

Giving Back and Staying Put: Volunteering as a Stabilizing Force in Relocation

Relocation in older adulthood has been shown to have health-related and environmental triggering factors. This study explores the relationship between volunteering in a community and relocation. Using data from the 2008 and 2010 Health and Retirement Study, which included 9,220 community-dwelling older individuals who were aged 65 years and older, our findings show that volunteering significantly reduces the likelihood of relocating out of the area, and such a relationship is partially mediated by having friends nearby. This study is innovative because it identifies a stabilizing mechanism important for understanding protective factors, such as volunteering, as a way communities can retain older adults.     

Family Support in Nursing Homes Serving Residents with a Mental Health History

Using 2003 nursing home data from the Minimum Data Set (MDS) database, this study investigated the role of family support among nursing homes serving residents with a mental health history. Exploratory factor analysis was used to create and test a conceptual model of family support using indicators located within the MDS database. Families were found to be in regular contact with their relatives and supportive of their care. In nursing homes, daily contact, an ongoing relationship, involvement in assessment, and being responsible for the resident constitute the model family support. This study advances the understanding of family support in nursing homes and conveys information to guide practice through proposing ways to enhance family support and involvement in nursing homes.     

Globalizations Forum on Middle East Protests: Commentary

The ‘Arab spring’ is part of a growing set of challenges to US hegemony and the capitalist world-system. The global economy is fueling the grievances that motivate protests while also providing tools that aid the spread of global protest movements. The global financial and other crises threaten the legitimacy of the entire system, opening up opportunities for challenges by popular groups even in the most authoritarian contexts. As the US and its Western allies confront more limited budgets, and as slower growth undermines stability in countries whose quiescence has been key to ensuring the flows of resources necessary for the operation of the global capitalist economy, we are destined to see more popular challenges to existing authorities. These challenges should be seen not simply as national challenges, but rather as part of a larger struggle for the transformation of the world-system.

La ‘primavera árabe’ es parte de una serie de retos que va en aumento contra la hegemonía de E.E.U.U. y el sistema mundial capitalista. La economía global está avivando los agravios que motivan las protestas mientras que también proveen herramientas que ayudan a difundir los movimientos de protesta globales. Las crisis financieras y otras globales amenazan la legitimidad del sistema entero, abriendo oportunidades para retos por grupos populares, incluso en los contextos más autoritarios. Así como en E.E.U.U. y sus aliados de occidente afrontan mayores presupuestos limitados, y el crecimiento más lento debilita la estabilidad en los países cuyo estado de quietud ha sido la clave para asegurar los flujos de recursos necesarios para el funcionamiento de la economía capitalista global, estamos destinados a ver más desafíos populares a las autoridades existentes. Estos retos no deben ser vistos simplemente como desafíos nacionales, pero como parte de una lucha mayor para la transformación del sistema mundial.

“阿拉伯之春”是对美国霸权和资本主义世界体系一系列日益增长的挑战的一部分。全球经济助长了这种激发抵抗的不满情绪,同时为全球抵抗运动的传播提供了工具。全球金融及其他危机威胁着整个体系的合法性,开启了在最为威权环境下普通大众发起挑战的机会。随着美国及其西方盟友面临更多的预算限制,亦随着渐缓的经济增长破坏着一些国家的稳定——这些国家的沉寂是确保全球资本主义经济运作所需要的资源流动的关键,我们注定会更多地看到大众对现存政权的挑战。这些挑战不应仅被视为国家内部的,而应视为更大的为世界体系转型而斗争的一部分。     

Parenting Discrepancy and Child Development in Chinese Context

Although parent–child discrepant perception of the family has been increasingly noted in the west, pertinent research is limited in Chinese societies. In addition, prior pertinent studies predominantly treated parent–child discrepant effects as independent of the general and aggregate family context, which are in fact inseparable. Furthermore, these studies tended to either look at the positive side of child outcomes or those negative ones. The present study, based on a community sample of 223 Chinese parent–child dyads, attempted to examine effects of parent–child discrepancy in effective parenting practices on both children’s positive, i.e. self-control and other perspective taking behavior, and negative outcomes, i.e. internalizing and externalizing problems, directly or indirectly through the mediator of children’s self-concept at the aggregate effective parenting context. Results largely support harmful effects of parent–child discrepancy in effective parenting on the child outcomes directly or indirectly through children’s self-concept. Besides, aggregate effective parenting practices are found to robustly contribute to the child outcomes directly and indirectly through children’s self-concept, even taking parent–child discrepant effects into account. What’s more important, the former is significantly moderated by the latter for its effects on the child outcomes, explicating the conditional nature of parent–child discrepant effects on child development. Contributions and implications of the current study applied in Chinese culture as well as future study directions are also discussed.     

Drawing out strengths and building capacity in social work with troubled young women

This paper compares the experiences of a group of marginalized young women with two groups that remained socially engaged. Drawing from a qualitative study of young women aged between 13 and 15 years, we identify four areas (understandings and experiences of well‐being, use of space, making wishes, and emotional and household labour) that illuminated the ways in which marginalized young women articulated their experiences differently from those young women who were still engaged in mainstream social life. Drawing on Ungar's work we consider the ways in which marginalized behaviours, which are typically interpreted as socially disruptive and troubled, can also be read as efforts by young women to create a consistent set of social meanings in their lives and to cement reliable relationships around them. Rather than wholly negative, we suggest that these socially disruptive and troubled behaviours should be understood as having health‐enhancing qualities, given the wider contextual challenges the young women faced, and as being the best choices they could make given their circumstances. Social work and support that assists young women on the margins needs to actively engage with these health‐enhancing qualities and to come to a sensitized understanding of the way in which these young women understand their interpersonal worlds.     

“The Guilt Thing”: Balancing Domestic and Professional Roles

Women’s representation in the workforce has increased dramatically over the past 30 years; yet, women “take a greater responsibility for the care of children” ( Equal Opportunities Commission, 2006 ). Research has suggested working mothers may experience guilt resulting from the social constrictions of a traditional model of intensive mothering ( B. Holcomb, 1998 ). Forty‐two audiotaped conversations of female teachers (n = 8) were collected in a British high school. Qualitative analyses of 3 conversations, in which 5 of the teachers discussed their professional and domestic responsibilities, demonstrated that the participants discursively aligned to 3 dominant interactional positions, accessibility, happiness, and separate spheres ( Y. Elvin‐Novak & H. Thomsson, 2001 ). The analyses also revealed the use of supportive conversational strategies such as co‐complaining and matching accounts.