THE EFFECT OF NONCONTRIBUTORY PENSIONS ON SAVING IN MEXICO

This paper examines the effects of noncontributory pension programs at the federal and state levels on Mexican households' saving patterns using micro data from the Mexican Income and Expenditure Survey. We find that the federal program curtails saving among households whose oldest member is either 18–54 or 65–69 years old, possibly through anticipation effects, a decrease in the longevity risk faced by households, and a redistribution of income between households of different generations. Specifically, these households appear to be reallocating income away from saving into human capital investments, like education and health. Generally, state programs have neither significant effects on household saving, nor does the combination of federal and state programs. Finally, with a few exceptions, noncontributory pensions have no significant impact on the saving of households with members 70 years of age or older—individuals eligible for those pensions, plausibly because of their dissaving stage in the lifecycle. (JEL D14, J26, O12, H55)     

Weibull and generalised exponential overdispersion models with an application to ozone air pollution

We consider the problem of estimating the mean and variance of the time between occurrences of an event of interest (inter-occurrences times) where some forms of dependence between two consecutive time intervals are allowed. Two basic density functions are taken into account. They are the Weibull and the generalised exponential density functions. In order to capture the dependence between two consecutive inter-occurrences times, we assume that either the shape and/or the scale parameters of the two density functions are given by auto-regressive models. The expressions for the mean and variance of the inter-occurrences times are presented. The models are applied to the ozone data from two regions of Mexico City. The estimation of the parameters is performed using a Bayesian point of view via Markov chain Monte Carlo (MCMC) methods.     

Relations Between Media,Perceived Social Support and Personal Well-Being in Adolescence

This paper’s main objective is to show relations between interest in media, perceived social support and adolescents’ personal well-being. For this purpose, 1,589 Brazilian adolescents answered a questionnaire containing Cummins’ Personal Well-Being, Vaux’s Social Support Appraisals and Casas’ interest in media scales. The media in study are: The Internet, computer games, video games, computer, cell phone and television. For the data analysis this research used Structural Equation Modeling, a statistical methodology based on the confirmation of hypotheses previously established by theoretical frameworks on data. A final model of relations between media, support and well-being was obtained with a fit considered satisfactory by the literature. Implications of media on adolescents’ well-being based on this model are considered.     

Bivariate beta regression models: joint modeling of the mean,dispersion and association parameters

In this paper a bivariate beta regression model with joint modeling of the mean and dispersion parameters is proposed, defining the bivariate beta distribution from Farlie–Gumbel–Morgenstern (FGM) copulas. This model, that can be generalized using other copulas, is a good alternative to analyze non-independent pairs of proportions and can be fitted applying standard Markov chain Monte Carlo methods. Results of two applications of the proposed model in the analysis of structural and real data set are included.     

A recursive approach for estimating missing observations in an univariate time series

A linear recursive technique that does not use the Kalman filter approach is proposed to estimate missing observations in an univariate time series. It is assumed that the series follows an invertible ARIMA model. The procedure is based on the restricted forecasting approach, and the recursive linear estimators are optimal in terms of minimum mean-square error.     

The 1970 US draft lottery revisited: a spatial analysis

Summary.  We revise the result of the 1970 selective service draft lottery in the USA following an open question that was suggested by Fienberg in a paper published in Science in 1971. The result of the drawings can be viewed as a particular spatial pattern which can be analysed by using general spatial tools adapted to our context. Approaches for assessing the complete spatial randomness for this spatial process on a finite support are proposed. More specifically, these approaches involve the number of events in a square window and a k ( r )-based function used to analyse stationary spatial point processes.