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The hypothesis that irritability and contingency detection are negatively correlated was examined in thirty‐one 6‐month‐old infants. Observation and maternal report‐based assessments of irritability were correlated with both a criterion score and a continuous score of contingency detection. Results indicated that greater irritability in infants was associated with lower contingency detection scores. Discussion focuses on identifying processes by which the 2 constructs may be associated. 相似文献
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Zhu Carolyn W. Moore Michael J. Clipp Elizabeth C. 《Review of Economics of the Household》2003,1(1-2):59-76
Informal caregivers of individuals with Alzheimer's disease spend a considerable amount of time providing care. In this paper, we use Grossman's health production and Becker's time allocation models to develop a model of informal care provision to elderly dementia patients. In our model, time inputs produce caregiving services, which provides utility to the caregiver, but reduces leisure. We assume that time is less productive of services on the margin as the disease progresses. In this framework, an increase in patients' disease severity does not necessarily increase informal caregiver time input. The cost of formal care establishes a reservation price for informal caregiving. When the costs of informal caregiving rise above this reservation level, the patient is institutionalized. We test empirically the effect of deterioration in the patients' condition, proxied by both disease severity and dementia problem behavior, on informal caregiving time. We find that dementia-related problem behaviors and functional limitations significantly increase inputs of informal caregiving time. Patients' problem behavior exerts a modifying effect on functional limitations, and patients' comorbidities have no effect on informal caregiving time. 相似文献
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Why do African Americans report higher levels of perceived job insecurity than whites? We analyze data from the 1996 and 1998 General Social Survey to test alternative predictions from the compositional, inclusive‐discrimination, and dispositional perspectives concerning the sources of the racial gap in perceived insecurity. Results from ordered probit regressions provide most support for the inclusive‐discrimination perspective, which maintains that employment practices associated with “modern racial prejudice” induce perceived insecurity on a widespread and generalized basis among African Americans. Accordingly, compared to whites, African Americans experience perceived insecurity net of human capital credentials and job/labor market characteristics. Additional analyses provide one qualification to these findings: dynamics associated with the inclusive‐discrimination perspective are more pronounced in the private sector than the public sector. 相似文献
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Using data from the National Longitudinal Study of Adolescent Health (Add Health), a nationally representative sample of youth from 7th to 12th grades, we examined how racial and ethnic identification overlap among Hispanic adolescents. We evaluated the relative proximity between race and ethnic identifiers among Hispanics. Empirical analyses suggest that the racial identification of other students at school has a significant impact on the odds of choosing particular racial identifiers. Both Hispanic and non-Hispanic schoolmates' racial identification is related to the racial identification of Hispanic adolescents. We also find evidence that both ethnicity and race are distinct stratifiers among Hispanics. Overall, our findings support the notion that Hispanic may be a more meaningful "racial" identity than black, white, or other, but we also find that racial identification and ethnic background are still important and meaningful dividers among Hispanic youth. 相似文献
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Lisa A. Gennetian Greg Duncan Virginia Knox Wanda Vargas Elizabeth Clark‐Kauffman Andrew S. London 《Journal of research on adolescence》2004,14(4):399-423
Using data from 8 random assignment studies and employing meta‐analytic techniques, this article provides systematic evidence that welfare and work policies targeted at low‐income parents have small adverse effects on some school outcomes among adolescents ages 12 to 18 years at follow‐up. These adverse effects were observed mostly for school performance outcomes and occurred in programs that required mothers to work or participate in employment‐related activities and those that encouraged mothers to work voluntarily. The most pronounced negative effects on school outcomes occurred for the group of adolescents who had a younger sibling, possibly because of the increased home and sibling care responsibilities they assumed as their mothers increased their employment. 相似文献
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Mohammad Salehi M. George A.F. Seber 《Australian & New Zealand Journal of Statistics》2004,46(3):483-494
Not having a variance estimator is a seriously weak point of a sampling design from a practical perspective. This paper provides unbiased variance estimators for several sampling designs based on inverse sampling, both with and without an adaptive component. It proposes a new design, which is called the general inverse sampling design, that avoids sampling an infeasibly large number of units. The paper provide estimators for this design as well as its adaptive modification. A simple artificial example is used to demonstrate the computations. The adaptive and non‐adaptive designs are compared using simulations based on real data sets. The results indicate that, for appropriate populations, the adaptive version can have a substantial variance reduction compared with the non‐adaptive version. Also, adaptive general inverse sampling with a limitation on the initial sample size has a greater variance reduction than without the limitation. 相似文献