Some Results Based on a Version of the Generalized Dynamic Entropies

We propose new dynamic measures of uncertainty based on the notion of generalized dynamic entropy introduced in Di Crescenzo and Longobardi (2006). These can uniquely determine distribution functions in continuous and discrete cases, and the characterizations of some well-known distributions are provided. We also define some orderings and aging notions based on the generalized dynamic measures, and prove some of their properties, obtaining as corollaries results that have recently appeared in the literature.     

A note on the mean residual life of a coherent system with a cold standby component

In this paper, we investigate the effect of a cold standby component on the mean residual life (MRL) of a system. When the system fails, a cold standby component is immediately put in operation. We particularly focus on the coherent systems in which, after putting the standby component into operation, the failure of the system is due to the next component failure. For these systems, we define MRL functions and obtain their explicit expressions. Also some stochastic ordering results are provided. Such systems include k-out-of-n systems. Hence, our results extend some results in literature.     

Barriers to Remarriage Among Older People: Viewpoints of Widows and Widowers

We conducted this research based on a qualitative approach to describe the opinions of older widows and widowers on remarriage obstacles. Based on purposive sampling and inclusion criteria, we chose 48 participants on maximum diversity of sex, age, education, employment, and socioeconomic status. Two thirds of the participants were female, 40% had spent more than 10 years widowed, and 65% were living with their children. We collected data individually through semistructured, face-to-face interviews. Based on conventional content analyses, 2 independent researchers implemented data analysis manually. Barriers to remarriage were finally categorized into 4 main themes: personal, normative, interactive, and financial factors. Results of this study showed that older people are more concerned about public opinions and social norms surrounding remarriage. As long as these thoughts and norms are not changed, the concept of remarriage among widows and widowers remains a vital taboo and concern.     

Goodness-of-fit tests based on Verma Kullback–Leibler information

In this article, a new consistent estimator of Veram’s entropy is introduced. We establish the entropy test based on the new information namely Verma Kullback–Leibler discrimination methodology. The results are used to introduce goodness-of-fit tests for normal and exponential distributions. The root of mean square errors, critical values, and powers for some alternatives are obtained by simulation. The proposed test is compared with other tests.     

AN EXPERIMENTAL STUDY OF KIN AND ETHNIC FAVORITISM

Ethnic and kinship ties have long been viewed as potential catalysts for favoritism, and hence corruption. In experiments conducted in three countries, we recruit siblings, coethnics and strangers and vary the relationship(s) between the players of a game to observe how kin and ethnic ties influence the willingness of two players to benefit one another at the expense of a third party. We see universal sibling favoritism, but ethnic favoritism, and favoritism toward other in-group members (friends) varies. We argue this may be driven in part by kinship institutions, since favoritism is more common in societies with denser kin networks. ( JEL D9, C9, D73, J12)     

A new three-parameter lifetime distribution

Many if not most lifetime distributions are motivated only by mathematical interest. Here, a new three-parameter distribution motivated mainly by lifetime issues is introduced. Some properties of the new distribution including estimation procedures are derived. Three real-data applications are described to show superior performance versus at least five of the known lifetime models.     

A Bayesian approach for analysing longitudinal nominal outcomes using random coefficients transitional generalized logit model: an application to the labour force survey data

A random-effects transition model is proposed to model the economic activity status of household members. This model is introduced to take into account two kinds of correlations; one due to the longitudinal nature of the study, which will be considered using a transition parameter, and the other due to the existing correlation between responses of members of the same household which is taken into account by introducing random coefficients into the model. The results are presented based on the homogeneous (all parameters are not changed by time) and non-homogeneous Markov models with random coefficients. A Bayesian approach via the Gibbs sampling is used to perform parameter estimation. Results of using random-effects transition model are compared, using deviance information criterion, with those of three other models which exclude random effects and/or transition effects. It is shown that the full model gains more precision due to the consideration of all aspects of the process which generated the data. To illustrate the utility of the proposed model, a longitudinal data set which is extracted from the Iranian Labour Force Survey is analysed to explore the simultaneous effect of some covariates on the current economic activity as a nominal response. Also, some sensitivity analyses are performed to assess the robustness of the posterior estimation of the transition parameters to the perturbations of the prior parameters.     

An Appraisal of Methods for the Analysis of Longitudinal Ordinal Response Data with Random Dropout Using a Nonhomogeneous Markov Model

There are many methods for analyzing longitudinal ordinal response data with random dropout. These include maximum likelihood (ML), weighted estimating equations (WEEs), and multiple imputations (MI). In this article, using a Markov model where the effect of previous response on the current response is investigated as an ordinal variable, the likelihood is partitioned to simplify the use of existing software. Simulated data, generated to present a three-period longitudinal study with random dropout, are used to compare performance of ML, WEE, and MI methods in terms of standardized bias and coverage probabilities. These estimation methods are applied to a real medical data set.