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291.
José?A.?Cabral?Vieira Ana?Rute?CardosoEmail author Miguel?Portela 《Journal of Economic Inequality》2005,3(2):145-168
Using a large linked employer-employee data set, this paper aims at quantifying the trend in worker segregation at the establishment level and its impact on wages in Portugal over a fifteen year period. We concentrate on the gender dimension, to answer the questions: What is the level of gender segregation across establishments in the Portuguese labor market and how has it evolved over time? What is the impact of segregation on wages? Is that impact different for men and women? Systematic and random components of segregation are computed. We use standard wage decomposition techniques to evaluate the impact of the composition of the labor force at the establishment level on wages. The results reveal a high degree of systematic gender segregation. A higher proportion of females in the establishment lowers females’ wages while, on the contrary, it raises males’ wages. The evidence gathered is consistent with the taste-based model of employer behavior and with the theory of sorting of workers across establishments based on their productivity. 相似文献
292.
Semidefinite programming (SDP) relaxations are proving to be a powerful tool for finding tight bounds for hard discrete optimization problems. This is especially true for one of the easier NP-hard problems, the Max-Cut problem (MC). The well-known SDP relaxation for Max-Cut, here denoted SDP1, can be derived by a first lifting into matrix space and has been shown to be excellent both in theory and in practice.Recently the present authors have derived a new relaxation using a second lifting. This new relaxation, denoted SDP2, is strictly tighter than the relaxation obtained by adding all the triangle inequalities to the well-known relaxation. In this paper we present new results that further describe the remarkable tightness of this new relaxation. Let
denote the feasible set of SDP2 for the complete graph with n nodes, let F
n denote the appropriately defined projection of
into
, the space of real symmetric n × n matrices, and let C
n denote the cut polytope in
. Further let
be the matrix variable of the SDP2 relaxation and X F
n be its projection. Then for the complete graph on 3 nodes, F
3 = C
3 holds. We prove that the rank of the matrix variable
of SDP2 completely characterizes the dimension of the face of the cut polytope in which the corresponding matrix X lies. This shows explicitly the connection between the rank of the variable Y of the second lifting and the possible locations of the projected matrix X within C
3. The results we prove for n = 3 cast further light on how SDP2 captures all the structure of C
3, and furthermore they are stepping stones for studying the general case n 4. For this case, we show that the characterization of the vertices of the cut polytope via rank Y = 1 extends to all n 4. More interestingly, we show that the characterization of the one-dimensional faces via rank Y = 2 also holds for n 4. Furthermore, we prove that if rank Y = 2 for n 3, then a simple algorithm exhibits the two rank-one matrices (corresponding to cuts) which are the vertices of the one-dimensional face of the cut polytope where X lies. 相似文献
293.
294.
Angel Martínez-Pina Ph.D. José Luis Guirao de Parga M.B.A. Rafael Fusté i Vallverdú Ph.D. Xavier Serrat Planas Ph.D. Miguel Martín Mateo Víctor Moreno Aguado Ph.D. 《Journal of gambling studies / co-sponsored by the National Council on Problem Gambling and Institute for the Study of Gambling and Commercial Gaming》1991,7(4):275-299
A sample of fifty-seven pathological gamblers and one hundred and fifteen controls (two per pathological gambler, matched as regards age and sex) was investigated. This sample received a complex battery of psychometric tests designed to evaluate two different axes: psychopathology and intelligence. The results obtained show that pathological gamblers have an unstable family and work background, that pathological gambling correlates with other addictions (alcohol, illness prone behavior, absenteeism, risk working, living alone and bereavement), that all the general and specific psychopathology vectors were significant in the addicts, and that the pathological gamblers' intelligence has characteristic factors.We thank Ricardo Cayuela (Line Staff, Barcelona) for his help in collecting the sample; Jordi Daura for data processing work; Mercedes Lemonier, psychologist, for her help in administering and correcting the tests; Consol Marina and Teresa Ruiz for their secretarial assistance and contact with the 172 study subjects. 相似文献
295.
Cristiano Cantore Miguel Len‐Ledesma Peter McAdam Alpo Willman 《Journal of the European Economic Association》2014,12(1):108-128
The response of hours to technology shocks is a key controversy in macroeconomics. We show that differences between RBC and NK models hinge on highly restrictive views of technology. We introduce CES production technologies and demonstrate that the response of hours depends on the factor‐augmenting nature of shocks and the capital–labor substitution elasticity in both models. We develop analytical expressions to establish the thresholds determining its sign. This opens new margins for shock identification combining theory and VAR evidence. We discuss how our models provide new robust restrictions for empirical work, especially using the labor income share. 相似文献
296.
Lucybel Mendez Nick Morelli Kelly D. Cromer Miguel Villodas 《Journal of research on adolescence》2023,33(1):154-168
Research shows comorbidity between posttraumatic stress symptoms (PTSS) and externalizing problems among polyvictimized youth. However, the impact of polyvictimization on the longitudinal co-development of PTSS and distinct forms of externalizing problems remains unclear. Growth trajectory modeling was used to address this gap. At ages 8, 12, and 16, polyvictimization was measured using youth, caregiver, and official records; whereas youth self-reported PTSS and caregivers reported aggression and delinquency. Results demonstrate that changes in PTSS and each externalizing domain were independent. Further, polyvictimization and PTSS/aggression were only associated at concurrent time points. In contrast, polyvictimization and delinquency were generally associated at concurrent and distal time points, suggesting that polyvictimization may have a more enduring impact on youths' delinquent behaviors than other symptoms. 相似文献
297.
Coparenting can be a development-enhancing or risk-promoting environment for infant regulatory capacity, mainly in the presence of adversity. This study aimed to analyze the association between positive and negative coparenting previous to the COVID-19 pandemic and infant regulatory capacity in the presence of the COVID-19 pandemic, an adverse condition. A sample of 71 first-born infants and their mothers and fathers from a longitudinal cohort in Portugal were assessed at 2 weeks postpartum before the COVID-19 pandemic and again at 6 months postpartum, before (n = 35) or during the COVID-19 pandemic (n = 36). Parents completed measures of positive and negative coparenting and infant regulatory capacity in both assessment waves. Results revealed that the presence of the COVID-19 pandemic moderates the association between mothers' and fathers' positive coparenting previous to the COVID-19 pandemic and infant regulatory capacity at 6 months. The association between positive coparenting and regulatory capacity was stronger in infants facing the COVID-19 pandemic, than in infants who did not face the COVID-19 pandemic. Positive coparenting previous to the COVID-19 pandemic may be a development-enhancing environment for infant regulatory capacity in the presence of the COVID-19 pandemic. Positive coparenting may buffer regulatory problems in infants facing adverse conditions. 相似文献