A new long-term survival model with dispersion induced by discrete frailty

Lifetime Data Analysis - Frailty models are generally used to model heterogeneity between the individuals. The distribution of the frailty variable is often assumed to be continuous. However, there...     

A Bayesian Analysis for Accelerated Lifetime Tests Under an Exponential Power Law Model with Threshold Stress

In this paper, we present a Bayesian methodology for modelling accelerated lifetime tests under a stress response relationship with a threshold stress. Both Laplace and MCMC methods are considered. The methodology is described in detail for the case when an exponential distribution is assumed to express the behaviour of lifetimes, and a power law model with a threshold stress is assumed as the stress response relationship. We assume vague but proper priors for the parameters of interest. The methodology is illustrated by a accelerated failure test on an electrical insulation film.     

Trends in online media relations: Web-based corporate press rooms in leading international companies

An analysis of 120 corporate websites from Denmark, France, Germany, Norway, Singapore, Spain, the United Kingdom and the United States reveals, for the first time, international results about the implementation and use of virtual press rooms. This article shows the importance that large international companies attribute to Web-based media centers to achieve organizational objectives and to meet journalists’ demands for information and audiovisual resources. The study also shows, however, that most press rooms are far from being complete, efficient, easy-to-use, reliable and updated on a daily basis. In fact, there is not a single country from those analyzed that consistently stands out from the rest. In most of them, good results in certain areas coexist with significant shortcomings in others, resulting in some cases in poor press rooms that may not achieve the desired public relations objectives.     

Sense of Belonging in School as a Protective Factor Against Drug Abuse Among Native American Urban Adolescents

This article presents the results of a study conducted with 243 Native American students who were part of a multi-ethnic sample of adolescents attending middle school in a large urban center in the Southwest region of the United States. Native adolescents who felt a stronger sense of belonging in their school were found to report a lower lifetime use of alcohol and cigarettes, lower cigarette and marijuana use in the previous month, lower frequency of current use of these substances, fewer substances ever used, and a later age of initiation into drug use than other Native students. Research implications are discussed in relationship to school environment, culturally-grounded prevention curricula, and school social work practice.     

Testing Inference in Inflated Beta Regressions under Model Misspecification

We consider testing inference in inflated beta regressions subject to model misspecification. In particular, quasi-z tests based on sandwich covariance matrix estimators are described and their finite sample behavior is investigated via Monte Carlo simulations. The numerical evidence shows that quasi-z testing inference can be considerably more accurate than inference made through the usual z tests, especially when there is model misspecification. Interval estimation is also considered. We also present an empirical application that uses real (not simulated) data.     

The Slaughtered and the Survivors: Collaboration Between Social Economy Organizations as a Key to Success in Times of Financial Crisis

The objective of this study is to analyze the aspects that allowed a critical part of Social Economy Organizations (SEOs) to survive a recession period, especially participation in collaborative networks. The financial stress of an SEO will depend on the resources and capabilities available to the organization. To analyze the financial stress of Spanish SEOs, we defined a sample of 714 SEOs. Approximately half of these organizations suffered from financial stress in the analyzed period (2009–2012). The results obtained in this study reveal the existence of three factors that distinguish organizations under financial stress: (a) a high dependence on government funding; (b) changes in the relationship between staff and volunteers; and (c) a lack of access to markets. The combination of these three elements results in an unsustainable situation for the organization. The development of a collaborative profile increases the SEO’s probability of surviving the adverse manifestations of its environment.     

How do industry and country impact firm performance? A national and supranational analysis

We contribute to the literature of the country, industry and firm effects on performance by developing an autoregressive cross-classified mixed-effect linear model that examines heterogeneity in the profitability of corporations in emerging and developed economies, as well as corporations located in different supranational regions. To this purpose, we simultaneously decompose abnormal returns into permanent and transitory components at the firm, industry, country and industry–country levels. We find that firms in emerging countries have significantly higher rates of performance persistence and different sources of persistence compared to firms located in developed countries. These differences are also evident between different supranational regions and countries at different levels of institutional development.