Exact distributions of two non-central generalized Wilks's statistics

We derive the exact expressions of the probability density function (pdf) and the cumulative distribution function (cdf) of Wilks's likelihood ratio criterion Λ and Wilks-Lawley's statistic U in the non-central linear and the non-central planar cases. Those expressions are given in rapidly converging infinite series and can be used for numerical computation. For applications, we compute the exact power of these statistics in a multivariate analysis of variance exercise, and show by simulation the precision of our analytic formulae.     

Work–family conflict: The importance of differentiating between different facets of job characteristics

This review study clarifies the relationships between job characteristics and work–family conflict (WFC) by differentiating among three facets of job characteristics: latent, perceived, and enacted. To date, research linking job characteristics to WFC has not distinguished the facets of job demands and job resources in this way. Such distinctions are important as a means of understanding the affective, behavioural, and cognitive processes involved in determining how and when job characteristics relate to WFC. Our review of 115 studies showed that perceived job characteristics have been most commonly explored in relation to WFC, whereas latent and enacted job characteristics have been hardly examined. While these findings may not be surprising, our contribution lies in reviewing the literature through the lens of these categories. Based on the findings, and through highlighting examples in the extant literature, we argue that understanding job characteristics in terms of both how they are perceived and enacted by workers will provide a deeper insight into the mechanisms underlying the relationship between job characteristics and WFC. In order to inform evidence-based interventions, future research must uncover the dynamic mechanisms underpinning the connection between job characteristics and WFC through a focus on enacted job facets and the cognitive, affective, and behavioural processes involved.     

Impacts of off‐farm employment on welfare,food security and poverty: Evidence from rural Vietnam

How off‐farm employment can enhance welfare in terms of food consumption and poverty alleviation is a critical question facing many developing countries. This study addressed that question by pursuing two objectives: (i) to quantify the impact of off‐farm employment on rural households’ welfare, food security and poverty; and (ii) to examine the factors that affect their decision to work off‐farm. Using panel data, we estimated a difference‐in‐difference combined with a propensity score matching model. The findings show that off‐farm employment improves income, ensures food security and contributes to poverty alleviation. The results also show that age, marital status, education, labour, financial capital, land, location, market access and losses from natural disasters are significant contributing factors to the decision to participate in off‐farm employment. The findings suggest that to improve the welfare of rural households, the Vietnamese government should proceed with policies that enhance their opportunities for participation in off‐farm employment.     

Canadian University Acknowledgment of Indigenous Lands,Treaties, and Peoples

At many Canadian universities it is now common to publicly acknowledge Indigenous lands, treaties, and peoples. Yet, this practice has yet to be considered as a subject of scholarly inquiry. How does this practice vary and why? In this paper we describe the content and practice of acknowledgment, linking this content to treaty relationships (or lack thereof). We show that acknowledgment tends to be one of five general types: of land and title (British Columbia), of specific treaties and political relationships (Prairies), of multiculturalism and heterogeneity (Ontario), of no practice (most of Quebec), and of people, territory, and openness to doing more (Atlantic). Based on these results, we conclude that the fluidity of acknowledgment as a practice, including changing meanings depending on the positionality of the acknowledger, need to be taken into account. Plusieurs universités Canadien pratique une reconnaissance des territoires, des traités, et des peoples autochtone en publique. Cette pratique, cependant, n'a jamais été considérée comme une enquête savante. Dans ce projet nous regardons comment les reconnaissances varie par institution et pourquoi. Nous trouvons qu'il y a un lien entre le contenu des reconnaissances et les relations traité. On démontre cinq forme des reconnaissances: territoire et titre (Colombie britannique); traité spécifique and les relations politiques (Prairies); multiculturalisme et hétérogénéité (Ontario); l'absence (la majorité du Québec); et des peoples, territoire et volonté a plus faire (Atlantique). Nous concluons que la fluidité de la reconnaissance, comme pratique, est fluide et doit prendre en considération la position de la personne qui le fait.     

Tail density estimation for exploratory data analysis using kernel methods

It is often critical to accurately model the upper tail behaviour of a random process. Nonparametric density estimation methods are commonly implemented as exploratory data analysis techniques for this purpose and can avoid model specification biases implied by using parametric estimators. In particular, kernel-based estimators place minimal assumptions on the data, and provide improved visualisation over scatterplots and histograms. However kernel density estimators can perform poorly when estimating tail behaviour above a threshold, and can over-emphasise bumps in the density for heavy tailed data. We develop a transformation kernel density estimator which is able to handle heavy tailed and bounded data, and is robust to threshold choice. We derive closed form expressions for its asymptotic bias and variance, which demonstrate its good performance in the tail region. Finite sample performance is illustrated in numerical studies, and in an expanded analysis of the performance of global climate models.     

Recalling sexual behavior: A methodological analysis of memory recall bias via interview using the diary as the gold standard

This study examined the effect of time lag on the validity of retrospective self‐reports of sexual behavior. Seventy‐five heterosexual students (44 women, 31 men) made daily recordings of sexual behavior, condom use, and alcohol or substance use for 1 month. Ability of respondents to recall sexual behavior recorded during this period was assessed at 1, 2, and 3 months after diary completion using recall interviews (25 interviewed at each interval). For vaginal intercourse, total recall error was significantly greater at 3 months than at 1 month post‐diary. For all other variables assessed, the 2‐ and 3‐month time intervals did not produce significant increases in total recall error. Higher frequency of vaginal intercourse, orgasm, and alcohol use prior to sexual activity were associated with total recall error for some but not all behaviors and outcomes. The results provide a partial validation of the diary‐interview recall model as a method for studying recall error.     

Recalling sexual behavior: a methodological analysis of memory recall bias via interview using the diary as the gold standard

This study examined the effect of time lag on the validity of retrospective self-reports of sexual behavior. Seventy-five heterosexual students (44 women, 31 men) made daily recordings of sexual behavior, condom use, and alcohol or substance use for 1 month. Ability of respondents to recall sexual behavior recorded during this period was assessed at 1, 2, and 3 months after diary completion using recall interviews (25 interviewed at each interval). For vaginal intercourse, total recall error was significantly greater at 3 months than at 1 month post-diary. For all other variables assessed, the 2- and 3-month time intervals did not produce significant increase in total recall error. Higher frequency of vaginal intercourse, orgasm, and alcohol use prior to sexual activity were associated with total recall error for some but not all behaviors and outcomes. The results provide a partial validation of the diary-interview recall model as a method for studying recall error.     

UNCONSTRAINED PILOT SELECTORS FOR SMOOTHED CROSS‐VALIDATION

Two of the most useful multivariate bandwidth selection techniques are the plug‐in and cross‐validation methods. The smoothed version of the cross‐validation method is known to reduce the variability of its non‐smoothed counterpart; however, it shares with the plug‐in choice the need for a pilot bandwidth matrix. Owing to the mathematical difficulties encountered in the optimal pilot choice, it is common to restrict this pilot matrix to be a scalar multiple of the identity matrix, at the expense of losing the flexibility afforded by the unconstrained approach. Here we show how to overcome these difficulties and propose a smoothed cross‐validation selector using an unconstrained pilot matrix. Our numerical results indicate that the unconstrained selector outperforms the constrained one in practice, and is a viable competitor to unconstrained plug‐in selectors.     

Access to social protection among people with disabilities: Evidence from Viet Nam

Although people with disabilities are frequently targeted as key beneficiaries of social protection, little is known on their access to existing programmes. This study uses mixed methods to explore participation in disability‐targeted and non‐targeted social protection programmes in Viet Nam, particularly in the district of Cam Le. In this district, social assistance and health insurance coverage among people with disabilities was 53 per cent and 96 per cent respectively. However, few accessed employment‐linked social insurance and other disability‐targeted benefits (e.g. vocational training, transportation discounts). Factors affecting access included the accessibility of the application process, disability assessment procedures, awareness and the perceived utility of programmes, and attitudes on disability and social protection.     

Maximizing misinformation restriction within time and budget constraints

Online social networks have become popular media worldwide. However, they also allow rapid dissemination of misinformation causing negative impacts to users. With a source of misinformation, the longer the misinformation spreads, the greater the number of affected users will be. Therefore, it is necessary to prevent the spread of misinformation in a specific time period. In this paper, we propose maximizing misinformation restriction (\(\mathsf {MMR}\)) problem with the purpose of finding a set of nodes whose removal from a social network maximizes the influence reduction from the source of misinformation within time and budget constraints. We demonstrate that the \(\mathsf {MMR}\) problem is NP-hard even in the case where the network is a rooted tree at a single misinformation node and show that the calculating objective function is #P-hard. We also prove that objective function is monotone and submodular. Based on that, we propose an \(1{-}1/\sqrt{e}\)-approximation algorithm. We further design efficient heuristic algorithms, named \(\mathsf {PR}\)-\(\mathsf {DAG}\) to show \(\mathsf {MMR}\) in very large-scale networks.