Geodesic Lagrangian Monte Carlo over the space of positive definite matrices: with application to Bayesian spectral density estimation

We present geodesic Lagrangian Monte Carlo, an extension of Hamiltonian Monte Carlo for sampling from posterior distributions defined on general Riemannian manifolds. We apply this new algorithm to Bayesian inference on symmetric or Hermitian positive definite (PD) matrices. To do so, we exploit the Riemannian structure induced by Cartan's canonical metric. The geodesics that correspond to this metric are available in closed-form and – within the context of Lagrangian Monte Carlo – provide a principled way to travel around the space of PD matrices. Our method improves Bayesian inference on such matrices by allowing for a broad range of priors, so we are not limited to conjugate priors only. In the context of spectral density estimation, we use the (non-conjugate) complex reference prior as an example modelling option made available by the algorithm. Results based on simulated and real-world multivariate time series are presented in this context, and future directions are outlined.     

Health Outcomes in Individuals with Problem and Pathological Gambling: An Analysis of the 2014 North Carolina Behavioral Risk Factor Survey System (BRFSS)

Problem and pathological gambling refers to subclinical and clinical levels of maladaptive gambling, respectively, and is associated with specific sociodemographic characteristics as well as a number of poor health outcomes. We examined such demographic, physical health, mental health, and health-related behaviors in a sample of 7045 low-risk gamblers and 244 problem/pathological gamblers. Participants completed the 2014 North Carolina Behavioral Risk Factor Surveillance System telephone survey. Using the National Opinion Research Center’s Diagnostic Screen for Gambling Disorders-CLiP, participants were categorized as either “problem/pathological gamblers” or “low-risk gamblers.” Problem/pathological gamblers were younger, more likely to be male, of ethnic minority status, unmarried, and of lower education than low-risk gamblers. No physical health variables differentiated the groups but problem/pathological gamblers reported experiencing significantly more adverse childhood experiences and engaging in significantly more tobacco and alcohol use compared to low-risk gamblers. Moreover, gender moderated relationships between gambling group and several of the alcohol use variables such that male problem/pathological gamblers exhibited greater alcohol use behavior than male low-risk gamblers but no such relationship was present in females. Overall, this study expands the current knowledgebase on disordered gambling and highlights the need to assess disordered gambling in public health samples. Clinical implications are discussed.     

Evaluating local food programs: The case of Select Nova Scotia

This study evaluated the effectiveness of the buy local food program Select Nova Scotia; a government program with the goal to increase awareness and consumption of Nova Scotia produced and processed agri-food products by Nova Scotians and visitors. The evaluation methodology was based on prior evaluation resources and local food consumer research. Data were gathered through a web panel survey; 877 respondents completed the survey in June 2010. The results suggest that the program is reaching a wider audience than just those predisposed to local food initiatives. In addition, awareness of Select Nova was related to perceptions of local benefits and barriers, as well as purchase motivation and behavior. Respondents who were aware of Select Nova Scotia rated societal benefits as more important and viewed location and price as less of a barrier; they were also more likely to be highly motivated to purchase local foods. This study also informs results found in previous consumer research studies and identifies marketing opportunities to enhance the effectiveness of local food programs. The results suggest that societal benefits might be used as a way to differentiate products with similar attributes.     

Risk of physical assault against school educators with histories of occupational and other violence: a case-control study

A case-control study design was used to investigate risks of work-related physical assault (PA) associated with a history of violent victimization among educators. A total of 6,469 state-licensed educators (Kindergarten - Grade 12) worked in the previous 12~months and were eligible to participate. Exposure data were collected from cases (reporting a PA event in previous 12 months, n=290) for the month before PA, and from controls (no work-related PA in previous 12 months; n=867) for a randomly selected working month. Odds ratios and 95% confidence intervals identified increased risks for educators with any prior history of work-related (17.3, 11.4-26.3) or non-work-related PA (2.0, 1.2-3.5). In addition, PA risk in the previous twelve months increased with the number of previous victimizations, and risk also increased for educators with histories of non-physical violence (work- and non work-related). The results present a compelling case for targeted interventions and further research.     

Looking at engagement and outcome from the perspectives of child protection workers and parents

This paper reports a study that sought to understand what facilitates engagement between parents and child protection workers and to ascertain the relationship between such engagement and intervention outcome. Quantitative and qualitative data were gathered through personal interviews with 131 worker-parent dyads (workers and corresponding parents receiving service) from 11 child protection agencies in Ontario, Canada. Measures included scales for engagement, parental well-being (depression and stress), and worker well-being (burnout, job satisfaction, stress). Outcome measures included perception of child safety, changed parenting practices and satisfaction. A relationship was found between workers' perception of parent engagement and parents' perception of their own engagement, as well as between the perceptions that workers and parents had around their own respective engagement. Workers who were satisfied with service outcomes were significantly more engaged than those who were unsatisfied. Parents thinking that their children were safer as a result of intervention were significantly more engaged than parents who thought that their children were less safe. The strongest reason given by parents for positive change was being able to trust their worker (p < .001) and believing that their worker was knowledgeable about parenting (p < .01). Qualitative data suggested that parents valued experienced workers because they thought such workers could better understand their problems and how to deal with them. Correspondingly, workers felt that experience enabled them to better understand clients' problems and provide more effective support. No relationship was found between parent engagement and parental depression or stress, but the mean depression score for parents placed them at risk of clinical depression. There was a negative correlation between worker stress and engagement. The study demonstrates that engagement between clients and workers is related to positive outcomes (as reported by workers and parents) and supports the contention that promoting engagement is integral to a successful child protection intervention.     

The “new” military and income inequality: A cross national analysis

Military expenditures have escalated over the last three decades in both developed and less developed countries, without a corresponding expansion of military personnel. Spending has instead been directed towards hi-tech weaponry, what we refer to as the “new” military. We hypothesize that this new, increasingly capital-intensive military is no longer a pathway of upward mobility or employer of last resort for many uneducated, unskilled, or unemployed people, with significant consequences for those individuals and society as a whole. One such consequence, we argue, is an increase in income inequality. We test this hypothesis with cross-national panel models, estimated for 82 developed and less developed countries from 1970 to 2000. Findings indicate that military capital-intensiveness, as measured by military expenditures per soldier, exacerbates income inequality net of control variables. Neither total military expenditures/GDP nor military participation has a significant effect. It appears from these findings that today’s “new” military establishment is abrogating its historical role as an equalizing force in society, with important policy implications.     

Bureaucratic encounters “after neoliberalism”: Examining the supportive turn in social housing governance

It is well established that encounters between welfare bureaucracies and their clients have been reconfigured under neoliberalism to address the problem of “welfare dependency.” Contemporary bureaucratic encounters therefore entail measures to activate clients’ entrepreneurial/self-governing capacities, and conditionality/sanctioning practices to deal with clients who behave “irresponsibly.” Despite the dominance of the neoliberal model, recent research has identified a counter-trend in the practices of housing services away from entrepreneurializing and punitive strategies and towards a more supportive approach. This paper examines this counter-trend and its implications for neoliberal welfare governance. To do this, it presents findings from research into social housing governance in Queensland, Australia, where the neoliberal focus on welfare independence, conditionality and sanctioning has been tempered by a new supportive approach focused on assisting vulnerable clients to maintain and benefit from access to welfare/housing support. Following Larner, we argue that this shift signals the emergence of an “after neoliberal” governmental formation, wherein key features of neoliberal governmentality are replaced by, or redeployed in the service of, progressive initiatives that address neoliberalism’s failings at the street level, but leave broader neoliberal policy settings undisturbed. We also challenge recent sociological accounts that construe supportive welfare practices as a function of an all-encompassing neoliberal project, arguing instead for appreciation of the contingency of these developments and the progressive political affordances that they entail.     

On the versatility of Little’s Law in operations management: a review and classification using vignettes

Abstract

Despite Little’s Law being considered as one of the ‘laws’ of operations management, evidence of its application in an empirical context is diverse and diffuse. Hence, this paper aims to identify, classify and consolidate published empirical applications of Little’s Law in a systematic manner to better understand its versatility. This paper undertakes a systematic literature review of the databases of the five main publishers of operations management journals and snowball sampling for additional papers. A final sample of 128 empirical journal articles is identified and categorized. Tactical, medium-term decisions relating to capacity dynamics and operations re-engineering are the most popular categories. To give further insights into versatility, vignettes for each category are developed. The review and vignettes confirm Little’s Law as a highly relevant paradigm to operations management decisions due to its empirical versatility across levels, sectors and time domains. The paper suggests four factors to underline the empirical versatility of Little’s Law in operations management: applicability, utility, simplicity and visibility.     

Lessons from meta‐analyses of randomized clinical trials for analysis of distributed networks of observational databases

Networks of constellations of longitudinal observational databases, often electronic medical records or transactional insurance claims or both, are increasingly being used for studying the effects of medicinal products in real‐world use. Such databases are frequently configured as distributed networks. That is, patient‐level data are kept behind firewalls and not communicated outside of the data vendor other than in aggregate form. Instead, data are standardized across the network, and queries of the network are executed locally by data partners, and summary results provided to a central research partner(s) for amalgamation, aggregation, and summarization. Such networks can be huge covering years of data on upwards of 100 million patients. Examples of such networks include the FDA Sentinel Network, ASPEN, CNODES, and EU‐ADR. As this is a new emerging field, we note in this paper the conceptual similarities and differences between the analysis of distributed networks and the now well‐established field of meta‐analysis of randomized clinical trials (RCTs). We recommend, wherever appropriate, to apply learnings from meta‐analysis to help guide the development of distributed network analyses of longitudinal observational databases.     

The propagation of lean thinking in SMEs

Abstract

Small and Medium-sized Enterprises (SMEs) play a pivotal role in economic growth, industrial output, and employment creation. However, SMEs are often ignored by researchers as far as the adoption of lean is concerned in comparison to Large Enterprises (LEs). Therefore, the literature regarding lean implementation in SMEs is not conspicuous, and many SMEs have only a limited understanding and awareness of lean. This paper offers a comprehensive literature review with a focus on the implementation of lean in SMEs and explores the applicability of lean thinking in such environments. An attempt is made to provide an analysis of lean practices that have been applied in SMEs and critical success factors for lean transformation in SMEs. It also contributes to the field of lean implementation research by proposing a framework for lean in SMEs and identifies the scope of future research.