On Rao score and PearsonX 2 statistics in generalized linear models

The identity of the Rao score and PearsonX ² statistics is well known in the areas where the latter was first introduced: goodness-of-fit in contingency tables and binary responses. We show in this paper that the same identity holds when the two statistics are used for testing goodness-of-fit of Generalized Linear Models. We also highlight the connections that exist between the two statistics when they are used for the comparison of nested models. Finally, we discuss some merits of these unifying results. Work financially supported by cofin. MIUR grants 2000 and 2002.     

Quasi-likelihood from<Emphasis Type="Italic">M</Emphasis>-estimators: A numerical comparison with empirical likelihood

In this paper we compare two robust pseudo-likelihoods for a parameter of interest, also in the presence of nuisance parameters. These functions are obtained by computing quasi-likelihood and empirical likelihood from the estimating equations which define robustM-estimators. Application examples in the context of linear transformation models are considered. Monte Carlo studies are performed in order to assess the finite-sample performance of the inferential procedures based on quasi-and empirical likelihood, when the objective is the construction of robust confidence regions.     

Sustainable consumption and third-party certification labels: Consumers’ perceptions and reactions

Compared with conventional products, sustainable products continue to attract relatively lower market shares. To increase customer acceptance, many sustainable products feature third-party certification labels (TPCL), yet it is unclear whether TPCL are effective and what processes and boundary conditions define their role in consumer decision making. Across three experimental studies, this research determines that sustainable products are characterized by credence qualities, associated with increased perceptions of risk, which negatively influence consumers' purchase intentions. Drawing on signaling theory, this study also shows that TPCL on sustainable products provide brand-like information cues that reduce the perceived risk of sustainable products. Finally, a third experimental study demonstrates that consumers must perceive TPCL as credible for them to reduce consumers’ risk perceptions.     

Employability of Young Italian Men after a Jobless Period, 1989–98

In this paper we investigate the existence of negative jobless duration dependence and the impact of jobless spells on future wages. Our findings are somewhat out of line compared with analogous explorations. We find evidence of very long unemployment duration of the young male labor force, higher than reported anywhere else in Western Europe, as well as large negative unemployment duration dependence. On the other hand, young Italian men experiencing jobless periods in their early careers face small re‐employment wage losses. Such losses do increase with the duration of joblessness, but they are lower than reported in the USA, Canada, the UK, France, and Spain.     

Subject-specific odds ratios in binomial GLMMs with continuous response

In a regression context, the dichotomization of a continuous outcome variable is often motivated by the need to express results in terms of the odds ratio, as a measure of association between the response and one or more risk factors. Starting from the recent work of Moser and Coombs (Stat Med 23:1843–1860, 2004) in this article we explore in a mixed model framework the possibility of obtaining odds ratio estimates from a regression linear model without the need of dichotomizing the response variable. It is shown that the odds ratio estimators derived from a linear mixed model outperform those from a binomial generalized linear mixed model, especially when the data exhibit high levels of heterogeneity.     

On the Empirical Likelihood Ratio for Smooth Functions of M-functionals

It is known that the empirical likelihood ratio can be used to construct confidence regions for smooth functions of the mean, Fréchet differentiable statistical functionals and for a class of M-functionals. In this paper, we argue that this use can be extended to the class of functionals which are smooth functions of M-functionals. In particular, we find the conditions under which the empirical log-likelihood ratio for this kind of functionals admits a χ² approxima tion. Furthermore, we investigate, by simulation methods, the related approximation error in some contexts of practical interest.