Bivariate censored regression relying on a new estimator of the joint distribution function

In this paper we study a class of M  -estimators in a regression model under bivariate random censoring and provide a set of sufficient conditions that ensure asymptotic n^1/2-convergence$n^{1/2}\mathrm{-}\mathrm{convergence}$. The cornerstone of our approach is a new estimator of the joint distribution function of the censored lifetimes. A copula approach is used to modelize the dependence structure between the bivariate censoring times. The resulting estimators present the advantage of being easily computable. A simulation study enlighten the finite sample behavior of this technique.     

Epidemiology of premenstrual symptoms and disorders

The aim of this paper is to review published literature on the types and prevalences of premenstrual disorders and symptoms, and effects of these on activities of daily life and other parameters of burden of illness. The method involved review of the pertinent published literature. Premenstrual disorders vary in prevalence according to the definition or categorization. The most severe disorder being premenstrual dysphoric disorder (PMDD) affects 3-8% of women of reproductive age. This disorder focuses on psychological symptoms whereas global studies show that the most prevalent premenstrual symptoms are physical. Both psychological and physical symptoms affect women's activities of daily life. A considerable burden of illness has been shown to be associated with moderate to severe premenstrual disorders. In conclusion, premenstrual symptoms are a frequent source of concern to women during their reproductive lives and moderate to severe symptoms impact on their quality of lives.     

Concepts de dépendance et ordres stochastiques pour des lois bidimensionnelles

Yanagimoto and Okamoto (1969) introduced a stochastic ordering that generalizes a concept of monotone regression dependence introduced by Lehmann (1966). In this paper, we define and examine the properties of three new orderings which imply that of Yanagimoto and Okamoto. One of these orderings is seen to extend Shaked's (1977) notion of DTP(0, 1), and another includes Lehmann's concept of positive likelihood-ratio dependence as a special case. The proposed orderings are also compared with the TP₂ positive-dependence ordering defined by Kimeldorf and Sampson (1987).     

On the influence of extreme parties in electoral competition with policy-motivated candidates

We study and compare equilibrium platforms in models of unidimensional electoral competition with two and four policy motivated parties. We first analyze the plurality game, where the party getting the most votes is elected and implements its proposed platform. Restrictions on the set of credible announcements are needed to get existence of equilibria. Comparing equilibria with two and four parties, we obtain that moderate parties react to the introduction of extreme parties by proposing the same or more extreme equilibrium platforms. We then study the proportional system, where the policy implemented is a weighted sum of the proposals, with the voting shares as weights. Here, the existence of extreme parties leads moderate ones to choose more centrist platforms. We finally test the robustness of our results with respect to, first, the enlargement of the strategy space to entry decisions and, second, to asymmetric distributions of voters' blisspoints.

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