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Many European countries during the 1990s and early 2000s tried to raise labor market flexibility by relaxing their employment protection legislation. This paper investigates whether the reforms have influenced job and employment stability for labor market entrants in Germany and Italy. Duration models are estimated using comparable administrative data for the two countries. The results provide, to some extent, evidence of a decrease in job stability. However, this is not accompanied by a compensating increase in employment stability during the first 3 years after labor market entry.  相似文献   
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The knowledge of the urban air quality represents the first step to face air pollution issues. For the last decades many cities can rely on a network of monitoring stations recording concentration values for the main pollutants. This paper focuses on functional principal component analysis (FPCA) to investigate multiple pollutant datasets measured over time at multiple sites within a given urban area. Our purpose is to extend what has been proposed in the literature to data that are multisite and multivariate at the same time. The approach results to be effective to highlight some relevant statistical features of the time series, giving the opportunity to identify significant pollutants and to know the evolution of their variability along time. The paper also deals with missing value issue. As it is known, very long gap sequences can often occur in air quality datasets, due to long time failures not easily solvable or to data coming from a mobile monitoring station. In the considered dataset, large and continuous gaps are imputed by empirical orthogonal function procedure, after denoising raw data by functional data analysis and before performing FPCA, in order to further improve the reconstruction.  相似文献   
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This paper analyses the effects of expected earnings and local markets conditions on the behaviour of young adults with high school diplomas. Decisions to either remain in the parental home or form a new household are modelled jointly with those of either gaining work experience or investing in a university education. Expected lifetime earnings are found to play a crucial role in determining the choice of studying and residing with parents. Poor labour market opportunities discourage young people from working and induce them to study. The cost of housing greatly influences the choice of working and leaving the parental home. Received: 23 March 2001/Accepted: 26 November 2001 All correspondence to Gianna Claudia Giannelli. Helpful comments by two anonymous referees are gratefully acknowledged. Responsible editor: John F. Ermisch.  相似文献   
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The flexible Dirichlet (FD) distribution (Ongaro and Migliorati in J. Multvar. Anal. 114: 412–426, 2013) makes it possible to preserve many theoretical properties of the Dirichlet one, without inheriting its lack of flexibility in modeling the various independence concepts appropriate for compositional data, i.e. data representing vectors of proportions. In this paper we tackle the potential of the FD from an inferential and applicative viewpoint. In this regard, the key feature appears to be the special structure defining its Dirichlet mixture representation. This structure determines a simple and clearly interpretable differentiation among mixture components which can capture the main features of a large variety of data sets. Furthermore, it allows a substantially greater flexibility than the Dirichlet, including both unimodality and a varying number of modes. Very importantly, this increased flexibility is obtained without sharing many of the inferential difficulties typical of general mixtures. Indeed, the FD displays the identifiability and likelihood behavior proper to common (non-mixture) models. Moreover, thanks to a novel non random initialization based on the special FD mixture structure, an efficient and sound estimation procedure can be devised which suitably combines EM-types algorithms. Reliable complete-data likelihood-based estimators for standard errors can be provided as well.  相似文献   
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ABSTRACT

This study applied a previously developed Postpartum Social Support Questionnaire to low-income, African American women. The 33-question survey was administered to 95 African American women between 4- and 8-weeks postpartum. The survey was readministered 2 weeks later. All women were of low socioeconomic status based on their qualification for public insurance. The questionnaire addresses subscales of partner, parent, in-law, and other friend/relative support. Responses were used to evaluate internal reliability of each subscale, test–retest correlation, and factor loading. Results were compared between women with and without a positive postpartum depression screen. Cronbach's alpha coefficients for each subscale ranged from .90 to .96. Test-retest correlation coefficients ranged from .72 to .87. Exploratory factor analysis with orthogonal varimax rotation was consistent with previously studied samples. Those women with positive postpartum depression screens had significantly lower social support scores (M = 122, SD = 36) than women with negative postpartum depression screens (M = 149, SD = 38), t(79) = ?2.62, p = .01. The Postpartum Social Support Questionnaire is a useful assessment in low-income, African American mothers.  相似文献   
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Abstract. Temporary work has been an important component of employment growth in Italy since the early 1990s. This paper focus upon labour market transitions of temporary workers in order to test whether temporary work enhances the subsequent labour market chances. We use propensity score matching to compare subsequent employment outcomes of people who have recently acquired a temporary job with those of people who remained unemployed. Individuals' hetero geneity explains a good amount of the raw differences in the subsequent labour market status of temporary workers and the comparison group. Yet there appears to be a sizable net gain from experiencing a temporary work. Our benchmark average estimate is a 30 percentage points rise in the ‘satisfactory employment’ chances 1 year after the start of the temporary work experience. The net gains are the largest for females and adult people and the areas with low unemployment; moreover, gains are the largest for the most recent years in our sample and for those people who were (according to the propensity score estimates) either least or most likely to exit from unemployment.  相似文献   
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The paper tests the hypothesis that private transfers can be explained by the existence of self-enforcing family constitutions prescribing the minimum level at which a person in middle life should support her young children and elderly parents. The test is based on the effect of a binding credit ration on the probability of making a money transfer, which can be positive only in the presence of family constitutions. Allowing for the possible endogeneity of the credit ration, we find that rationing has a positive effect on the probability of giving money if the potential giver is under the age of retirement, but no significant effect if the person is already retired. This appears to reject the hypothesis that transfer behavior is the outcome of unfettered individual optimization on the part of either altruistic or exchange motivated agents, but not the one that individuals optimize subject to a self-enforcing family constitution. The policy implications are briefly discussed.
Daniela Vuri (Corresponding author)Email:
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