Estimation and diagnostic for skew-normal partially linear models

Partially linear models (PLMs) are an important tool in modelling economic and biometric data and are considered as a flexible generalization of the linear model by including a nonparametric component of some covariate into the linear predictor. Usually, the error component is assumed to follow a normal distribution. However, the theory and application (through simulation or experimentation) often generate a great amount of data sets that are skewed. The objective of this paper is to extend the PLMs allowing the errors to follow a skew-normal distribution [A. Azzalini, A class of distributions which includes the normal ones, Scand. J. Statist. 12 (1985), pp. 171–178], increasing the flexibility of the model. In particular, we develop the expectation-maximization (EM) algorithm for linear regression models and diagnostic analysis via local influence as well as generalized leverage, following [H. Zhu and S. Lee, Local influence for incomplete-data models, J. R. Stat. Soc. Ser. B 63 (2001), pp. 111–126]. A simulation study is also conducted to evaluate the efficiency of the EM algorithm. Finally, a suitable transformation is applied in a data set on ragweed pollen concentration in order to fit PLMs under asymmetric distributions. An illustrative comparison is performed between normal and skew-normal errors.     

Slashed generalized exponential distribution

In this paper, we introduce an extension of the generalized exponential (GE) distribution, making it more robust against possible influential observations. The new model is defined as the quotient between a GE random variable and a beta-distributed random variable with one unknown parameter. The resulting distribution is a distribution with greater kurtosis than the GE distribution. Probability properties of the distribution such as moments and asymmetry and kurtosis are studied. Likewise, statistical properties are investigated using the method of moments and the maximum likelihood approach. Two real data analyses are reported illustrating better performance of the new model over the GE model.     

Slashed generalized Rayleigh distribution

We introduce a new family of distributions suitable for fitting positive data sets with high kurtosis which is called the Slashed Generalized Rayleigh Distribution. This distribution arises as the quotient of two independent random variables, one being a generalized Rayleigh distribution in the numerator and the other a power of the uniform distribution in the denominator. We present properties and carry out estimation of the model parameters by moment and maximum likelihood (ML) methods. Finally, we conduct a small simulation study to evaluate the performance of ML estimators and analyze real data sets to illustrate the usefulness of the new model.     

Stagnation only on the surface? The implications of skill and family responsibilities for the gender wage gap in Sweden, 1974–2010

The wage differential between women and men persists in advanced economies despite the inflow of women into qualified occupations in recent years. Using five waves of the Swedish Level‐of‐Living Survey (LNU), this paper explores the gender wage gap in Sweden during the 1974–2010 period overall and by skill level. The empirical analyses showed that the general gender wage gap has been nearly unchanged for the past 30 years. However, the gender difference in wage in less qualified occupations fell considerably, whereas the gender pay gap remained stable for men and women in qualified occupations. The larger significance of family responsibilities for wages in qualified occupations is one likely explanation for this result.     

Toward a multi‐ethnic public sphere? Media consumption in highly diverse districts in Spain

This article examines media consumption in highly diverse districts in Spain as representative of recent changes in this field due to new immigration to countries in Southern Europe in times of crisis. Drawing on findings from two surveys, we observed a decrease in access to media specifically aimed at audiences of minority cultures between 2010 and 2012. It is suggested that this decline is not due to a modification in media consumption habits by minority groups, but rather the economic crisis of 2008. Furthermore, we study the consumption of minority media by natives: we observe that youth and more educated individuals consume other cultures’ minority media to a greater extent, particularly the press, radio, and Internet news sources. We suggest that elements are present that public administrations could utilize to further develop a multi‐ethnic public sphere. Finally, we explore the emergence of a new transnational dimension to the multi‐ethnic public sphere.     

Adaptation of the short version of the Psychological Capital Questionnaire (PCQ-12) into Spanish / Adaptación al español de la versión reducida del Cuestionario de Capital Psicológico (PCQ-12)

Psychological capital (PsyCap) has been a topic of increasing interest in the last decade. However, there is a lack of validated instruments in Spanish to map PsyCap and its consequences for individuals’ well-being. Consequently, the goal of this study is to adapt the 12-item short version of the Psychological Capital Questionnaire (PCQ-12) to the Spanish context by analysing its internal consistency and reliability, factor solution and external validity. Results indicated that the PCQ-12 exhibited good Cronbach’s alpha (.87) and omega coefficient (.93) values in a sample from a vehicle inspection company (n = 798). As expected, results also revealed that a second-order factor structure provided the best fit. Moreover, PsyCap is associated with increased job engagement (β = .579; R²_adjusted = .333), decreased job burnout (β = ?.409; R²_adjusted = .166), and lower psychological distress (β = ?.349; R²_adjusted = .121) (all p < .01), which provided additional support for using the PCQ-12 in the Spanish context. Implications for theory and practice are discussed.     

Individual Uncertainty About Longevity

This article presents an assessment of individual uncertainty about longevity. A survey performed on 3,331 French people enables us to record several survival probabilities per individual. On this basis, we compute subjective life expectancies (SLE) and subjective uncertainty regarding longevity (SUL), the standard deviation of each individual’s subjective distribution of her or his own longevity. It is large and equal to more than 10 years for men and women. Its magnitude is comparable to the variability of longevity observed in life tables for individuals under 60, but it is smaller for those older than 60, which suggests use of private information by older respondents. Our econometric analysis confirms that individuals use private information—mainly their parents’ survival and longevity—to adjust their level of uncertainty. Finally, we find that SUL has a sizable impact, in addition to SLE, on risky behaviors: more uncertainty on longevity significantly decreases the probability of unhealthy lifestyles. Given that individual uncertainty about longevity affects prevention behavior, retirement decisions, and demand for long-term care insurance, these results have important implications for public policy concerning health care and retirement.     

Corruption and the ‘Paradox of Redistribution’

The existing literature on the determinants of income redistribution has identified a ‘paradox’. Namely, that countries with a high degree of market income inequality redistribute little, which is in disagreement with the median voter theorem. In a first step, this paper outlines several mechanisms that explain why government corruption might be partially responsible for this ‘paradox’. In a second step, different corruption perception indices and an instrumental variable approach are used to provide empirical evidence that indicates a significant negative impact of corruption on redistribution levels for a sample of 148 developing and developed countries. This finding suggests that, next to political and need factors, government corruption explains to some extent the ‘paradox of redistribution’. This is especially true for many developing countries, given that they typically have relatively high degrees of corruption and low levels of redistribution.     

Impact of support networks for breastfeeding: A multicentre study

Background

The rates of breastfeeding worldwide are slowly improving since 1996. Europe is still trailing behind the global breastfeeding incidence and prevalence rates. Thus, breastfeeding promotion, protection, prolongation and support have become an important challenge as breastfeeding sharply decreases in the first six months of life.

Life Course Changes in Smoking by Gender and Education: A Cohort Comparison Across France and the United States

Widening of educational disparities and a narrowing female advantage in mortality stem in good part from disparities in smoking. The changes in smoking and mortality disparities across cohorts and countries have been explained by an epidemic model of cigarette use but are also related to life course changes. To better describe and understand changing disparities over the life course, we compare age patterns of smoking in three cohorts and two nations (France and the US) using smoking history measures from the 2010 French health barometer (N = 20,940) and the 2010 US National Health Interview Survey Sample Adult File (N = 20,444). The results demonstrate statistically significant widening of gender and educational differences from adolescence to early and middle adulthood, thus accentuating the disparities already emerging during adolescence. In addition, the widening disparities over the life course have been changing across cohorts: age differences in educational disparities have grown in recent cohorts (especially in France), while age differences in gender disparities have narrowed. The findings highlight the multiple sources of inequality in smoking and health in high-income nations.