Bias in Age at Marriage in Family Reconstitutions: Evidence from French-Canadian Data

Age-at-marriage estimates from family reconstitutions may be biased downward when they are based only on marriages of people who continue to live in their parish of birth, because when the probability of migrating rises with age, younger people are selected in preference to older ones. Micro-simulations show that the bias can have dramatic effects. In this paper French-Canadian data are used to investigate the importance of the bias and to verify empirically the micro-simulation results. Although a high proportion of people moved between birth and marriage, the bias had virtually no effect, given the specific characteristics of the migrations. If one cannot avoid discussing the timing of migration before marriage, when measuring age at first marriage using only data on “stayers”, it is just possible that in most settings, it is the same for those who lived in their parish of birth, and those who had moved.     

Comparing poverty and deprivation dynamics: Issues of reliability and validity

In this paper we seek to establish if earlier findings relating to the relationship between income poverty persistence and deprivation persistence could be due to a failure to take measurement error into account. To address this question, we apply a model of dynamics incorporating structural and error components. Our analysis shows a general similarity between latent poverty and deprivation dynamics. In both cases we substantially over-estimate the probability of exiting from poverty or deprivation. We observe a striking similarity across dimensions for both observed and latent outcomes. In both cases levels of poverty and deprivation persistence are higher for the latent case. However, there is no evidence that earlier results relating to the differences in the determinants of poverty and deprivation persistence are a consequence of differential patterns of reliability. Taking measurement error into account seems more likely to accentuate rather than diminish the contrasts highlighted by earlier research. Since longitudinal differences relating to poverty and deprivation cannot be accounted for by measurement error, it seems that we must accept that we are confronted with issues relating to validity rather than reliability. Even where we measure these dimensions over reasonable periods of time and allow for measurement error, they continue to tap relatively distinct phenomenon. Thus, if measures of persistent poverty are to constitute an important component of EU social indicators, a strong case can be made for including parallel measures of deprivation persistence and continuing to explore the relationship between them.     

Evaluation of the "Lose Your Excuse" public service advertising campaign for tweens to save energy

This study evaluates the 2008-2009 "Lose your Excuse" public service advertising (PSA) campaign on energy efficiency targeting 8- to 12-year-olds, intended to increase knowledge, foster proactive attitudes, and change energy usage behaviors. Baseline and two follow-up surveys were conducted with online samples representative of the national population of households with kids with online access. Almost half (47%) of the tweens recognized at least one ad from the campaign. Ad recognition was positively associated with knowledge, proactive attitudes, and energy-saving behavior. Propensity score analysis confirmed a small but measurable and statistically significant effect on energy-saving behavior. The discussion section compares these results to public health campaigns in terms of ghost awareness, reach, and effect size.     

The effects of strength training on memory in older adults

The authors examined whether resistance training has an effect on working memory span. Participants included 210 community-residing older adults with at least one disability from the Strong for Life program, a randomized controlled trial that examined the effects of home-based resistance exercise. Memory was assessed with the WAIS backward digit span at baseline and 3 and 6 months into the intervention. Although there were no differences between the experimental treatment and control groups in average levels of memory change, within the treatment group change in resistance level during the intervention was a significant predictor of memory change, controlling for age, education, sex, and disability level. The results suggest that strength training can benefit memory among older adults, especially when using higher resistance levels.     

Adapted Couple Therapy (ACT) for Pathological Gamblers: A Promising Avenue

The study of the effectiveness of treatment for pathological gambling constitutes a field that is still largely unexplored. To date, the models assessed primarily target the individual and include little or no involvement of the family circle. Yet, the deleterious effects of gambling on loved ones and especially spouses are well recognized. Further, the addition of a couple modality to individual treatment has been shown to be effective on many levels in the treatment of substances use disorders. This article therefore proposes a critical review of (1) the literature providing a better understanding of the complex interactions between the couple relationship and pathological gambling, (2) studies on the effects of couple therapies on gamblers and their partners. We then present the therapeutic model developed by our team of clinician-researchers in collaboration with actors from Québec clinical settings: Adapted Couple Therapy (ACT) for pathological gamblers. In the Québec context, this model will serve as a complement to an individual cognitive-behavioral treatment model that has been proven effective and is employed throughout the Canadian province. The assessment of couple therapies could reveal avenues of solutions to better assist pathological gamblers who tend to drop-out of treatment and relapse.     

Median loss decision theory

In this paper, we argue that replacing the expectation of the loss in statistical decision theory with the median of the loss leads to a viable and useful alternative to conventional risk minimization particularly because it can be used with heavy tailed distributions. We investigate three possible definitions for such medloss estimators and derive examples of them in several standard settings. We argue that the medloss definition based on the posterior distribution is better than the other two definitions that do not permit optimization over large classes of estimators. We argue that median loss minimizing estimates often yield improved performance, have resistance to outliers as high as the usual robust estimates, and are resistant to the specific loss used to form them. In simulations with the posterior medloss formulation, we show how the estimates can be obtained numerically and that they can have better robustness properties than estimates derived from risk minimization.     

A new universal resample-stable bootstrap-based stopping criterion for PLS component construction

We develop a new robust stopping criterion for partial least squares regression (PLSR) component construction, characterized by a high level of stability. This new criterion is universal since it is suitable both for PLSR and extensions to generalized linear regression (PLSGLR). The criterion is based on a non-parametric bootstrap technique and must be computed algorithmically. It allows the testing of each successive component at a preset significance level \(\alpha \). In order to assess its performance and robustness with respect to various noise levels, we perform dataset simulations in which there is a preset and known number of components. These simulations are carried out for datasets characterized both by \(n>p\), with n the number of subjects and p the number of covariates, as well as for \(n<p\). We then use t-tests to compare the predictive performance of our approach with other common criteria. The stability property is in particular tested through re-sampling processes on a real allelotyping dataset. An important additional conclusion is that this new criterion gives globally better predictive performances than existing ones in both the PLSR and PLSGLR (logistic and poisson) frameworks.     

On Hobbes’s state of nature and game theory

Hobbes’s state of nature is often analyzed in two-person two-action non-cooperative games. By definition, this literature only focuses on duels. Yet, if we consider general games, i.e., with more than two agents, analyzing Hobbes’s state of nature in terms of duel is not completely satisfactory, since it is a very specific interpretation of the war of all against all. Therefore, we propose a definition of the state of nature for games with an arbitrary number of players. We show that this definition coincides with the strategy profile considered as the state of nature in two-person games. Furthermore, we study what we call rational states of nature (that is, strategy profiles which are both states of nature and Nash equilibria). We show that in rational states of nature, the utility level of any agent is equal to his maximin payoff. We also show that rational states of nature always exist in inessential games. Finally, we prove the existence of states of nature in a class of (not necessarily inessential) symmetric games.