Socioeconomic Status and Obesity Gradient over Age:New Evidence from China.

This paper presents a systematic analysis of the impact of socioeconomic status (SES) on overweight and obesity in China and investigates how and why the SES-obesity gradient differs with age. Using a longitudinal sample drawn from the China Health and Nutrition Survey (CHNS), I find that body mass index (BMI) is positively associated with SES during early childhood but becomes inversely related to childhood SES as children age into adulthood. Estimation results show that children from low SES families are less likely to be overweight or obese than their median and high SES peers. The results from subsamples stratified by living area reveal that the SES gaps of obesity are generally larger for urban residents than rural residents. Females are significantly less likely to be overweight than males in China. The SES during childhood has independent effects after controlling for respondents’ contemporaneous SES. The relationship between the contemporaneous SES of a male adult and his chance of being overweight or obese is significantly positive, while the contemporaneous SES of a female adult is negatively related to her chance of being overweight or obese.Overweight and Obesity, Socioeconomic Status, China

The Occupation, Marriage, and Fertility Choices of Women: A Life-Cycle Model

An extensive literature in labor economics recognizes that the life-cycle labor force participation of a woman is highly associated with her family choices. There is, however, virtually no study going further to incorporate female occupational choices. This paper attempts to fill this gap in labor supply literature by examining the interrelatedness of occupation, marital status and fertility choices of women over the life cycle. A discrete choice dynamic utility maximization model is constructed to investigate how relevant determinants influence a woman’s career and family path and how these decisions interplay with each other. Using longitudinal data on women from the 1979 youth cohort of the National Longitudinal Survey of Youth, I estimate my model through the maximum likelihood estimation method in a dynamic programming fashion which takes into account the uncertainties from random arrivals of job opportunities, unexpected failure of birth control and temporary shocks to family earnings. The estimation results of structural parameters indicate that women’s lifecycle patterns of occupation, marriage and contraceptive behaviors vary significantly with their observable characteristics such as age, education, ability, race, and the presence of young children.Human Capital; Occupational Choice; Life Cycle Model; Marriage; Fertility.

Implication of BaBar's new data on the Ds1(2710)D_{s1}(2710) and DsJ(2860)D_{sJ}(2860)

The strong decays of the $D_{s1}(2710)$ and $D_{sJ}(2860)$ are investigated in the framework of the $^3P_0$ model. Its decay properties newly reported by the BaBar Collaboration can be reasonably accounted for in the presence of the $D_{s1}(2710)$ being a mixture of the $D_s(2 ^3S_1)$ and $D_s(1 ^3D_1)$. The orthogonal partner of the $D_{s1}(2710)$ is expected to have a mass of about $2.66\sim 2.9$ GeV in quark models and a width of about $40\sim 60$ MeV in the $^3P_0$ model. The predicted decay properties turn out to be consistent with the BaBar's new data in both the orthogonal partner of the $D_{s1}(2710)$ and the $D_s(1 ^3D_3)$ interpretations for the $D_{sJ}(2860)$. The available experimental information is not enough to distinguish these two possibilities. The $E1$ radiative transitions of the $D_{s1}(2710)$ and $D_{sJ}(2860)$ are also studied. We tend to conclude that the $D_{s1}(2710)$ can be identified as a mixture of the $D_s(2 ^3S_1)$ and $D_s(1 ^3D_1)$, and the $D_{sJ}(2860)$ could be either the orthogonal partner of the $D_{s1}(2710)$ or the $D_s(1 ^3D_3)$. Further experimental information on the $D_{sJ}(2860)$ in the $D_s\eta$, $D^\ast_s\eta$, and $DK^\ast$ channels is needed.Comment: 13 pages, 2 figures, version accepted for publication in Phys. Rev.

Kondo correlation and spin-flip scattering in spin-dependent transport through a quantum dot coupled to ferromagnetic leads

We investigate the linear and nonlinear dc transport through an interacting quantum dot connected to two ferromagnetic electrodes around Kondo regime with spin-flip scattering in the dot. Using a slave-boson mean field approach for the Anderson Hamiltonian having finite on-site Coulomb repulsion, we find that a spin-flip scattering always depresses the Kondo correlation at arbitrary polarization strength in both parallel and antiparallel alignment of the lead magnetization and that it effectively reinforces the tunneling related conductance in the antiparallel configuration. For systems deep in the Kondo regime, the zero-bias single Kondo peak in the differential conductance is split into two peaks by the intradot spin-flip scattering; while for systems somewhat further from the Kondo center, the spin-flip process in the dot may turn the zero-bias anomaly into a three-peak structure.Comment: 4 pages, 2 figure

Quantum transport through double-dot Aharonov-Bohm interferometry in Coulomb blockade regime

Transport through two quantum dots laterally embedded in Aharonov-Bohm interferometry with infinite intradot and arbitrary interdot Coulomb repulsion is analyzed in the weak coupling and Coulomb blockade regime. By employing the modified quantum rate equations and the slave-boson approach, we establish a general dc current formula at temperatures higher than the Kondo temperature for the case that the spin degenerate levels of two dots are close to each other. We examine two simple examples for identical dots - no doubly occupied states and no empty state. In the former, completely destructive coherent transport and phase locking appear at magnetic flux $\Phi=\Phi_{0}/2$ and $\Phi=0$ respectively; in the latter, partially coherent transport exhibits an oscillation with magnetic flux having a period of $\Phi_0$.Comment: 8 pages, 3 figure