Nonparametric estimation of survival functions for doubly censored observations when the lifetime hazard rate is proportionally related to the censoring hazard rates

Let T, X and Y be non-negative random variables, where T is the time of occurrence of an event of interest, X and Y being the lefl and right censoring variables respectively.

In this paper we propose a nonparametric estimator of the survival function, ST, when T, X and Y are supposed to be independent and their corresponding hazard rates are proportionally related. In this way, our results extend Ebrahimi's work (1985) to the doubly censored data case.     

Pooling in Dynamic Panel-Data Models: An Application to Forecasting GDP Growth Rates

In this article, we analyze issues of pooling models for a given set of N individual units observed over T periods of time. When the parameters of the models are different but exhibit some similarity, pooling may lead to a reduction of the mean squared error of the estimates and forecasts. We investigate theoretically and through simulations the conditions that lead to improved performance of forecasts based on pooled estimates. We show that the superiority of pooled forecasts in small samples can deteriorate as the sample size grows. Empirical results for postwar international real gross domestic product growth rates of 18 Organization for Economic Cooperation and Development countries using a model put forward by Garcia-Ferrer, Highfield, Palm, and Zellner and Hong, among others illustrate these findings. When allowing for contemporaneous residual correlation across countries, pooling restrictions and criteria have to be rejected when formally tested, but generalized least squares (GLS)-based pooled forecasts are found to outperform GLS-based individual and ordinary least squares-based pooled and individual forecasts.     

A Generalized Log-Normal Model for Grouped Survival Data

It is common to have experiments in which it is not possible to observe the exact lifetimes but only the interval where they occur. This sort of data presents a high number of ties and it is called grouped or interval-censored survival data. Regression methods for grouped data are available in the statistical literature. The regression structure considers modeling the probability of a subject's survival past a visit time conditional on his survival at the previous visit. Two approaches are presented: assuming that lifetimes come from (1) a continuous proportional hazards model and (2) a logistic model. However, there may be situations in which none of the models are adequate for a particular data set. This article proposes the generalized log-normal model as an alternative model for discrete survival data. This model was introduced by Chen (1995 Chen , G. ( 1995 ). Generalized Log-normal distributions with reliability application . Comput. Stat. Data Anal. 19 : 300 – 319 . [Google Scholar]) and it is extended in this article for grouped survival data. A real example related to a Chagas disease illustrates the proposed model.     

An Alternative Estimation Approach for the Heterogeneity Linear Mixed Model

In this article, an alternative estimation approach is proposed to fit linear mixed effects models where the random effects follow a finite mixture of normal distributions. This heterogeneity linear mixed model is an interesting tool since it relaxes the classical normality assumption and is also perfectly suitable for classification purposes, based on longitudinal profiles. Instead of fitting directly the heterogeneity linear mixed model, we propose to fit an equivalent mixture of linear mixed models under some restrictions which is computationally simpler. Unlike the former model, the latter can be maximized analytically using an EM-algorithm and the obtained parameter estimates can be easily used to compute the parameter estimates of interest.     

Dialogic literary gatherings and out‐of‐home child care: Creation of new meanings through classic literature

Research on out‐of‐home child care has revealed that foster care programmes focused on educational attainment and reading have the potential to improve the academic outcomes of children in care. However, no studies have examined which elements of these programmes positively benefit children's emotional well‐being. This article presents evidence of the positive effects of implementing a successful educational action, dialogic literary gatherings, in a children's residential care institution. A qualitative study using a communicative‐oriented methodology was conducted and involved five participant observations and eight daily life stories with children in out‐of‐home care in Catalonia (Spain). The children's reflections demonstrated that reading classic books, such as Dickens' Oliver Twist, deeply influenced their feelings and self‐conceptions and created new and exciting meaning in their lives.     

Sickness and disability policies: Reform paths in OECD countries between 1990 and 2014

We analysed sickness and disability policies for the working‐age population in a number of OECD countries, between the years 1990 and 2014. Existing evidence suggests that there has been a broad shift in focus from passive income maintenance to employment incentives and reintegration policies. We have updated detailed policy scores provided by the OECD to estimate model‐based country clusters. Our results indicate that countries have pursued different types of reforms consisting of a combination of integration and compensation measures. The reforms of recent decades have led to the emergence of a distinct cluster of Northern and Continental European countries characterised by a combination of strong employment‐oriented policies and comparatively high social protection levels. An analysis of recent reforms shows a continued expansion of measures that foster employment as well as instances of retrenchment in the compensation dimension. Diversity of policy settings across country groups, however, remains substantial.     

Cooperative Institutions and Inequality in the OECD: Bringing the Firm Back In*

Objective. To examine the relationship between firm‐level cooperation, inequality, and redistribution in 18 advanced industrialized democracies. Methods. The relationships are investigated using multiple regression analyses of institutional, political, and economic variables. Results. Multilevel models reveal that contrary to neocorporatism, firm‐level cooperative ties have significant inegalitarian effects, particularly in the distribution of pretax, pretransfer market income. The effects, however, are also felt in the distribution of posttax, posttransfer income. Conclusion. By paying attention to the effect of firm‐level cooperation, the study sheds new light on inequality in the OECD as a result of both market‐based and nonmarket coordination.