Unified multivariate survival model with a surviving fraction: an application to a Brazilian customer churn data

In this paper we propose a new lifetime model for multivariate survival data in presence of surviving fractions and examine some of its properties. Its genesis is based on situations in which there are m types of unobservable competing causes, where each cause is related to a time of occurrence of an event of interest. Our model is a multivariate extension of the univariate survival cure rate model proposed by Rodrigues et al. [37 J. Rodrigues, V.G. Cancho, M. de Castro, and F. Louzada-Neto, On the unification of long-term survival models, Statist. Probab. Lett. 79 (2009), pp. 753–759. doi: 10.1016/j.spl.2008.10.029[Crossref], [Web of Science ®] , [Google Scholar]]. The inferential approach exploits the maximum likelihood tools. We perform a simulation study in order to verify the asymptotic properties of the maximum likelihood estimators. The simulation study also focus on size and power of the likelihood ratio test. The methodology is illustrated on a real data set on customer churn data.     

Influence diagnostics for the Weibull-Negative-Binomial regression model with cure rate under latent failure causes

In this paper, we propose a flexible cure rate survival model by assuming that the number of competing causes of the event of interest follows the Negative Binomial distribution and the time to event follows a Weibull distribution. Indeed, we introduce the Weibull-Negative-Binomial (WNB) distribution, which can be used in order to model survival data when the hazard rate function is increasing, decreasing and some non-monotonous shaped. Another advantage of the proposed model is that it has some distributions commonly used in lifetime analysis as particular cases. Moreover, the proposed model includes as special cases some of the well-know cure rate models discussed in the literature. We consider a frequentist analysis for parameter estimation of a WNB model with cure rate. Then, we derive the appropriate matrices for assessing local influence on the parameter estimates under different perturbation schemes and present some ways to perform global influence analysis. Finally, the methodology is illustrated on a medical data.     

Bayesian estimation and influence diagnostics of generalized partially linear mixed-effects models for longitudinal data

This paper develops a Bayesian approach to obtain the joint estimates of unknown parameters, nonparametric functions and random effects in generalized partially linear mixed models (GPLMMs), and presents three case deletion influence measures to identify influential observations based on the φ-divergence, Cook's posterior mean distance and Cook's posterior mode distance of parameters. Fisher's iterative scoring algorithm is developed to evaluate the posterior modes of parameters in GPLMMs. The first-order approximation to Cook's posterior mode distance is presented. The computationally feasible formulae for the φ-divergence diagnostic and Cook's posterior mean distance are given. Several simulation studies and an example are presented to illustrate our proposed methodologies.     

儒家的尚"中"与道家的崇"大"——儒道和谐观的差异与融合

"和谐"作为中国传统文化的一个核心范畴,是一个多层次、立体的概念,儒家的尚"中"思想及由此而发展起来的"中和"观念与道家的崇"大"思想及由此而来的"大和"观念是构成这一理论的两大基石,前者为"和谐"观念的形成提供了秩序平衡与个体节中,后者则带来了本体追求与辩证观念.在《易传》与《中庸》中二者达到融合.     

Connecting the gendered door: women, violence and doorwork

This paper explores the emerging role of women who work as 'bouncers', or doorstaff, in the night-time economy and examines how the cultural capital of the female bouncer is connected to the methods utilized to control licensed premises. It is drawn from a study that combined ethnographic observations and interviews in five major UK cities which explored a diverse range of issues such as gendered bodies, femininities and violence; the changing needs of the night-time economy in the UK and the experiences of women engaged in 'non-traditional' occupations. In this paper, we draw on interview data with one particular category of female door staff; women who share similar histories of exposure to violence and violent cultures, and we examine how their experiential knowledge of violence equips them with the resources to 'work the doors'. Our attention focuses on this group of women, who we refer to as 'The Connected', and examine how they are 'doing gender' when they negotiate violence 'on the door'     

The changing practice of eating: evidence from UK time diaries, 1975 and 2000

This paper examines some central themes about change in consumption behaviour through an empirical investigation of the practice of eating. It analyses patterns of food consumption in the UK using time diary data from 1975 and 2000. The practice of eating is decomposed into four component activities which are used to explore systematically the inter-relationships between social processes - such as commodification and temporal fragmentation - and ways of providing and consuming food. It charts the expansion of eating out, the degree to which it substitutes for other eating activities, and the implications of its development for social relations and the temporal organization of daily life. Analysis reveals that food consumption continues to be differentiated along established lines of social division, although the content of those divisions has changed and varies across components of the practice. Increasing commodification of the food chain is documented, but without appearing to have a corrosive impact on household organization or social relationships. While tendencies indicative of temporal fragmentation are revealed, counter-tendencies exist which suggest that the practice of eating is resilient to many forms of external pressure. Finally, the application of a practice-based analytical approach permits critical evaluation of theories of social transformation.     

How Satisfied are Spouses with their Leisure Time? Evidence from Europe

This paper first identifies the determinants of spouses’ satisfaction levels within the household with respect to their leisure time and, secondly, characterizes whether their preferences have some degree of altruistic or egoistic character in regard to this particular satisfaction. To that end, it formulates a theoretical framework from the collective family model whose stochastic formulations are estimated for 14 EU countries. The general empirical results first reveal that the presence of children has a significantly negative impact on the leisure satisfaction of both spouses. Then, increases in individual incomes lead to lower own leisure satisfaction levels. Both husbands and wives show egoistic behavior with respect to the labor and non-labor incomes (wage rate) of their respective spouses’ satisfaction levels.

Bayesian t-tests for correlations and partial correlations

In this paper, we develop Bayes factor based testing procedures for the presence of a correlation or a partial correlation. The proposed Bayesian tests are obtained by restricting the class of the alternative hypotheses to maximize the probability of rejecting the null hypothesis when the Bayes factor is larger than a specified threshold. It turns out that they depend simply on the frequentist t-statistics with the associated critical values and can thus be easily calculated by using a spreadsheet in Excel and in fact by just adding one more step after one has performed the frequentist correlation tests. In addition, they are able to yield an identical decision with the frequentist paradigm, provided that the evidence threshold of the Bayesian tests is determined by the significance level of the frequentist paradigm. We illustrate the performance of the proposed procedures through simulated and real-data examples.