A modified common factor model for modelling mortality jointly for both sexes

Journal of Population Research - There is an increasing attention on the joint modelling of multiple populations. Populations are related in several ways, such as neighbouring countries, females...     

A simple procedure for the selection of significant effects

Summary.  Given a large number of test statistics, a small proportion of which represent departures from the relevant null hypothesis, a simple rule is given for choosing those statistics that are indicative of departure. It is based on fitting by moments a mixture model to the set of test statistics and then deriving an estimated likelihood ratio. Simulation suggests that the procedure has good properties when the departure from an overall null hypothesis is not too small.     

Robustness of testing the equality of two slopes in simple linear structural relationships

The usual test of the equality of two slopes in a simple structural relation-ship is the test formed from the normal approximation using the Fisher information matrix, assuming two explanatory variables are independent. This paper examines the robustness if the explanatory variables are, in fact, dependent. A more efficient estimator is derived for a matched pair situation.     

Portmanteau test for conditional heteroscedasticity, using ranks of squared residuals

Squared residual autocorrelations have been found useful in detecting departures from linearity in time series models. This is especially the case with data exhibiting heterogeneity in variances. A rank test is proposed which is much more robust than its parametric counterpart.     

La médiane simpliciale d'Oja: Existence,unicité et stabilité

Oja (1983) examined various ways of measuring location, scatter, skewness, and kurtosis for multivariate distributions. Among other measures of location, he introduced a generalised median known in this paper under the name of the Oja median. In our study of the existence of that median, we show that Oja's definition can only be applied to distributions having a mean. In dimension d θ 2, we establish that the usual method of extension breaks down, which raises the question of the validity of the concept as a notion of median. Two fundamental theoretical properties of that median are also considered: uniqueness and consistency.     

Measuring credibility of compensatory preference statements when trade-offs are interval determined

This paper studies how an overall fuzzy preference relation can be constructed in the compensatory context of the simple additive difference model, when imprecision on the trade-offs has to be taken into account. Three credibility indices of preferences are analysed and illustrated by a numerical example. Arguments are presented supporting the use of the third index, for which an interesting transitivity property (which was an open problem) is proved.     

Households,Families and Prospective Economic Mobility in Mexico

The study analyzed poverty as a function of households’ demographic composition using a longitudinal random sample of 4268 urban and rural households that were followed-up from 2005/6 to 2009/12 in Mexico to estimate short-term changes in living conditions. Well-being was measured as the dwelling unit’s number of rooms, water source, sanitary services, garbage disposal, and fuel. Mobility paths included not poor–not poor, poor–poor, not poor–poor, and poor–not poor. Independent variables included household composition, family characteristics, residential changes, schooling, and occupation. Female headship and older adults negatively impacted poverty, whereas economic dependents may be negatively or positively associated. Fertility incentives for low-income populations are not advisable. Working-age adults contribute only if income-generating opportunities exist locally.     

Efficient heterogeneous sampling for stochastic simulation with an illustration in health care applications

In modeling disease transmission, contacts are assumed to have different infection rates. A proper simulation must model the heterogeneity in the transmission rates. In this article, we present a computationally efficient algorithm that can be applied to a population with heterogeneous transmission rates. We conducted a simulation study to show that the algorithm is more efficient than other algorithms for sampling the disease transmission in a subset of the heterogeneous population. We use a valid stochastic model of pandemic influenza to illustrate the algorithm and to estimate the overall infection attack rates of influenza A (H1N1) in a Canadian city.     

Assessing Participation and Effectiveness of the Peer-Led Approach in Youth Sexual Health Education: Systematic Review and Meta-Analysis in More Developed Countries

Sexual health education for young people is crucial not only for development of norms but also for protection against vulnerabilities during this stage in life. Although several systematic reviews have examined the effectiveness of peer-led sex education, none have focused on the extent of peer participation. The purpose of this review was to evaluate peer-led sexual health education interventions in more developed countries (MDCs). Electronic and manual searches across five social science, education, and medical databases were conducted. Fifteen articles were selected in total. Most (10 of 15) studies gave low or no responsibility to peers. The majority of articles found improvements in sexual health knowledge (13 of 14) and attitudes (11 of 15) at postintervention stages. Two studies showed improved self-efficacy, and three showed behavioral changes. A preliminary synthesis of effectiveness and level of participation was done. Meta-analysis revealed a large effect on knowledge change (Hedges’ g = 0.84, 95% confidence interval [CI]: 0.43 to 1.25) and a medium effect on attitude change (Hedges’ g = 0.49, 95% CI: 0.19 to 0.80). Peer-led interventions could be a powerful tool. This review shows that this approach is effective in changing knowledge and attitudes but not behaviors. Further research and action are needed to understand optimal implementation.