Multivariate log-skewed distributions with normal kernel and their applications

We introduce two classes of multivariate log-skewed distributions with normal kernel: the log canonical fundamental skew-normal (log-CFUSN) and the log unified skew-normal. We also discuss some properties of the log-CFUSN family of distributions. These new classes of log-skewed distributions include the log-normal and multivariate log-skew normal families as particular cases. We discuss some issues related to Bayesian inference in the log-CFUSN family of distributions, mainly we focus on how to model the prior uncertainty about the skewing parameter. Based on the stochastic representation of the log-CFUSN family, we propose a data augmentation strategy for sampling from the posterior distributions. This proposed family is used to analyse the US national monthly precipitation data. We conclude that a high-dimensional skewing function lead to a better model fit.     

Parenting in the Context of Deportation Risk

Nearly 5.1 million children younger than age 18 live with at least one undocumented parent, about 7% of the U.S. child population. Between 2010 and 2013, an estimated 300,000 parents of U.S. citizen children were deported. Raising children in the context of deportation risk increases overall parenting stress for undocumented Latino parents. To investigate this and understand the experience of undocumented parenting, the authors interviewed 70 undocumented parents in two Southwest cities from 2012 to 2013. The authors frame their analysis using the lens of the problem of “illegality.” There are three domains of stressors associated with parenting in the context of deportation risk: trapped parenting, threat of family separation, and altered family processes. The authors discuss these findings in the context of the literature on undocumented families and parenting stress and connect these findings to the current sociopolitical context experienced by Latino families in the United States .     

Metrology and ergonomic mensuration parameters

This poster intends to show how measurement, its concepts and methods are decisive to the ergonomic praxis and why their agents should be aware of how incertainty can be taken in the process in order to increase the accuracy of measurement and findings.     

Deporting Fathers: Involuntary Transnational Families and Intent to Remigrate among Salvadoran Deportees

One‐fourth of deportees from the United States are parents of US‐citizen children. We do not know how separation from families affects remigration among deportees, who face high penalties given unlawful reentry. We examined how family separation affects intent to remigrate among Salvadoran deportees. The majority of deportees with children in the United States were also separated from their spouse, and the vast majority had US‐citizen children. Family separation was the single most important factor affecting intent to remigrate. We interpret these findings in light of immigration policy debates.     

Les rejetés de la modernisation

In Brazil unlike France two very split labour markets co-exist, the formal and the informal. On the formal labor market in Brazil, union rights prevail, and wage-earners are protected unlike in the informal labor market where none of this exists. Raising industry to an international level pushed many wage-earners out of the formal sector during the 1980s. Did they find jobs elsewhere? If so, in which branches of the economy? To provide answers, two files are crossed, their data having been made longitudinal. Dismissed workers’ trajectories from 1989 till 1995 in two branches and two regions are analyzed: the automobile industry in the São Paulo area and the petrochemical industry in the São Salvador (Bahia) area. These career trajectories shed light on how modernization has affected quite different labor markets; it also brings to the foreground the concept of a systemic restructuring of the labor market. — Special issue: Latin America.     

Estimating the grid of time-points for the piecewise exponential model

One of the greatest challenges related to the use of piecewise exponential models (PEMs) is to find an adequate grid of time-points needed in its construction. In general, the number of intervals in such a grid and the position of their endpoints are ad-hoc choices. We extend previous works by introducing a full Bayesian approach for the piecewise exponential model in which the grid of time-points (and, consequently, the endpoints and the number of intervals) is random. We estimate the failure rates using the proposed procedure and compare the results with the non-parametric piecewise exponential estimates. Estimates for the survival function using the most probable partition are compared with the Kaplan-Meier estimators (KMEs). A sensitivity analysis for the proposed model is provided considering different prior specifications for the failure rates and for the grid. We also evaluate the effect of different percentage of censoring observations in the estimates. An application to a real data set is also provided. We notice that the posteriors are strongly influenced by prior specifications, mainly for the failure rates parameters. Thus, the priors must be fairly built, say, really disclosing the expert prior opinion.     

A class of dynamic piecewise exponential models with random time grid

A novel fully Bayesian approach for modeling survival data with explanatory variables using the Piecewise Exponential Model (PEM) with random time grid is proposed. We consider a class of correlated Gamma prior distributions for the failure rates. Such prior specification is obtained via the dynamic generalized modeling approach jointly with a random time grid for the PEM. A product distribution is considered for modeling the prior uncertainty about the random time grid, turning possible the use of the structure of the Product Partition Model (PPM) to handle the problem. A unifying notation for the construction of the likelihood function of the PEM, suitable for both static and dynamic modeling approaches, is considered. Procedures to evaluate the performance of the proposed model are provided. Two case studies are presented in order to exemplify the methodology. For comparison purposes, the data sets are also fitted using the dynamic model with fixed time grid established in the literature. The results show the superiority of the proposed model.     

Wage Mobility in Israel: The Effect of Sectoral Concentration

Using a unique eight-year data set, merging population census and national insurance data, the paper examines and compares patterns of wage mobility in Israel. First, the public and the private sectors are compared. Second, within each of these sectors, a distinction is made between sub-sector groupings that exhibit a high level of concentration and those that are more diffuse and unregulated. Based on alternative measures of wage mobility, the central finding of the paper is that the extent of wage mobility in a given economic sector is negatively related to the degree of concentration in that sector.     

Ergonomic assessment of porridge roaming sale system

This paper makes suggestions for the realization of an ergonomic intervention, guided by the method of Moraes and Mont'Alv?o (2009), in the system of street vending of porridge, to improve the working conditions of this sales segment. Specifics are given about this practice and its problems, from ergonomic analysis comes to suggestions for improvements to be applied to a new system.