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841.
Despite the historical highs for age at first marriage, little is known about the causal relationship between marriage delay and wages, and more importantly, the mechanisms driving such relationship. We attempt to fill the void. Building on an identification strategy proposed in Dahl (Demography 47:689–718, 2010), we first establish the causal wage effects of marriage delay. We then propose ways to distinguish among competing theories and hypotheses, as well as the channels through which marriage delay affects wages. Specifically, we take advantage of their different implications for causal relationship, across gender and sub-populations. We reach two conclusions. First, we find a positive causal impact of marriage delay on wages, with a larger effect for women. Comparison of IV and OLS estimates suggests that the observed relationship between marriage delay and wages is attributed to both selection in late marriages and true causal effects. Second, we find strong evidence that the positive, causal effects are almost exclusively through increased education for both men and women.  相似文献   
842.
We investigate the relationship between economic freedom and international migration for the 1980–2010 period using a dataset on migration from 91 emerging countries to the 20 most attractive OECD destination countries. We find that more economic freedom at home discourages high-skilled migration, but not low-skilled migration. The negative association between economic freedom and high-skilled emigration also holds when we estimate (dynamic) panel models that allow for endogeneity in the economic freedom-migration nexus. In sum, our findings suggest that high-skilled migration is especially responsive to the economic incentives resulting from economic freedom.  相似文献   
843.
This paper stems from the observation that there are two worldwide trends, pension reform and population ageing, and asks whether the two may be related. Exploring the cases of pension reform in different countries, we find that, although they are very different, the cases share a common characteristic: they shift risks away from workers towards those who are retired. Furthermore, population ageing, by increasing the weight of the elderly relative to working generations, raises the price of intergenerational risk sharing. Combining these findings, we argue and show formally that pension reform can be seen as a welfare-best response to population ageing.  相似文献   
844.

Background

The prevalence of fear of birth has been estimated between 8–30%, but there is considerable heterogeneity in research design, definitions, measurement tools used and populations. There are some inconclusive findings about the stability of childbirth fear.

Aim

to assess the prevalence and characteristics of women presenting with scores ≥60 on FOBS-The Fear of Birth Scale, in mid and late pregnancy, and to study change in fear of birth and associated factors.

Methods

A prospective longitudinal cohort study of a one-year cohort of 1212 pregnant women from a northern part of Sweden, recruited in mid pregnancy and followed up in late pregnancy. Fear of birth was assessed using FOBS-The fear of birth scale, with the cut off at ≥60.

Findings

The prevalence of fear of birth was 22% in mid pregnancy and 19% in late pregnancy, a statistically significant decrease. Different patterns were found where some women presented with increased fear and some with decreased fear. The women who experienced more fear or less fear later in pregnancy could not be differentiated by background factors.

Conclusions

More research is needed to explore factors important to reduce fear of childbirth and the optimal time to measure it.  相似文献   
845.
Early in the 30-year HIV/AIDS pandemic in Sub-Saharan Africa, epidemiological studies identified formal education attainment as a risk factor: educated Sub-Saharan Africans had a higher risk of contracting HIV/AIDS than their less educated peers. Later demographic research reported that by the mid-1990s the education effect had reversed, and education began to function as a social vaccine. Recent counter-evidence finds a curvilinear pattern, with the association between educational attainment and HIV/AIDS infection changing from positive to negative across the education gradient. To reconcile these inconsistent conclusions, a hypothesis is developed and tested that education at early stages functioned as a risk factor and later functioned (and continues to function) as a social vaccine. We reason that this shift in the direction of the education effect was concurrent with changes in the public health environment in SSA that early on heightened material benefits from educational attainment but later heightened cognitive benefits from schooling. Using the 2003/2004 Demographic Health Surveys from four Sub-Saharan African countries (Cameroon, Ghana, Kenya and Tanzania), we tested this hypothesis (differential effects of schooling) using non-linear regression analysis (probit), identifying the different public health periods and controlling for confounding factors. The results support the hypothesis that the education effect shifted historically in the HIV/AIDS pandemic in SSA as we hypothesized.  相似文献   
846.
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848.
The Kidney Exchange Problem (KEP) is a combinatorial optimization problem and has attracted the attention from the community of integer programming/combinatorial optimisation in the past few years. Defined on a directed graph, the KEP has two variations: one concerns cycles only, and the other, cycles as well as chains on the same graph. We call the former a Cardinality Constrained Multi-cycle Problem (CCMcP) and the latter a Cardinality Constrained Cycles and Chains Problem (CCCCP). The cardinality for cycles is restricted in both CCMcP and CCCCP. As for chains, some studies in the literature considered cardinality restrictions, whereas others did not. The CCMcP can be viewed as an Asymmetric Travelling Salesman Problem that does allow subtours, however these subtours are constrained by cardinality, and that it is not necessary to visit all vertices. In existing literature of the KEP, the cardinality constraint for cycles is usually considered to be small (to the best of our knowledge, no more than six). In a CCCCP, each vertex on the directed graph can be included in at most one cycle or chain, but not both. The CCMcP and the CCCCP are interesting and challenging combinatorial optimization problems in their own rights, particularly due to their similarities to some travelling salesman- and vehicle routing-family of problems. In this paper, our main focus is to review the existing mathematical programming models and solution methods in the literature, analyse the performance of these models, and identify future research directions. Further, we propose a polynomial-sized and an exponential-sized mixed-integer linear programming model, discuss a number of stronger constraints for cardinality-infeasible-cycle elimination for the latter, and present some preliminary numerical results.  相似文献   
849.
This study examined racial–ethnic minority and white identified participants’ perceptions of racial microaggressions in four video scenarios involving a white professor and a black student. Participants (N = 261) were randomly assigned to observe a one of the four video conditions. The video involved an interaction with no microaggression, a very ambiguous microaggression, an ambiguous microaggression, or an overt microaggression. Participants rated their observations of (a) negative emotions toward the committer (white professor) and receiver (black student) of the microaggression, (b) positive emotions toward the committer and receiver of the microaggression, (c) perceptions on the degree of biasedness of committer, and (d) degree of positive perceptions of the committer. Analysis compared ratings of two groups, including racial–ethnic minority and white observers. We found a significant difference between the overt condition and other three conditions on negative emotions, positive emotions, and attributions of the professor (i.e., cultural biasedness and positive perceptions). However, there were no differences between the no microaggression, very ambiguous, and ambiguous conditions. No significant differences between racial–ethnic minority and white participants’ ratings were detected. Implications for training, practice, and future research are offered in our discussion.  相似文献   
850.
Many Americans endorse a colorblind racial ideology, meaning they strive to “not see race” and emphasize sameness and equal distribution of resources across racial lines. Currently, there is an absence of studies examining the personality and individual difference correlates of racial colorblindness. The current study investigated the association between three different aspects of racial colorblindness (unawareness of racial privilege, unawareness of institutional discrimination, and unawareness of blatant racism) and the Big 5, empathy, and aggression in white undergraduates. Our results revealed two divergent patterns. Unawareness of racial privilege was related to lower openness and perspective taking, but more empathic concern, whereas unawareness of blatant racism and unawareness of institutional discrimination were related to lower agreeableness, perspective taking, and empathic concern. These results are discussed in relation to the broader literature on prejudice and personality.  相似文献   
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