Do Multinationals' R&D Activities Stimulate Indigenous Entrepreneurship? Evidence from China's "Silicon Valley"

Using a unique firm-level dataset from China's "Silicon Valley," we investigate how multinational enterprises (MNEs) affect local entrepreneurship and R&D activities upon entry. We find that R&D activities of MNEs in an industry stimulate entry of domestic firms into the same industry and enhance R&D activities of newly entering domestic firms. By contrast, MNEs' production activities or domestic firms' R&D activities do not have such effect. Since MNEs are technologically more advanced than domestic firms, our findings suggest that diffusion of MNEs' advanced knowledge to potential indigenous entrepreneurs through MNEs' R&D stimulates entry of domestic firms.

Child Health and the Income Gradient: Evidence from China

Though the positive income gradient of child health is well documented in developed countries, evidence from developing countries is rare. Few studies attempt to identify a causal link between family income and child health. Utilizing unique longitudinal data from the China Health and Nutrition Survey, we have found a positive, age-enhancing income gradient of child health, measured by height-for-age z scores. The gradient is robust to alternative specifications and a comprehensive set of controls. Using the fact that the rural tax reform implemented since 2000 created an exogenous variation in family income across regions and over time, we explore a causal explanation for the income gradient, and find that it has a very strong independent causal effect on child health.child health, income gradient, rural tax reform

Small radii of neutron stars as an indication of novel in-medium effects

At present, neutron star radii from both observations and model predictions remain very uncertain. Whereas different models can predict a wide range of neutron star radii, it is not possible for most models to predict radii that are smaller than about 10 km, thus if such small radii are established in the future they will be very difficult to reconcile with model estimates. By invoking a new term in the equation of state that enhances the energy density, but leaves the pressure unchanged we simulate the current uncertainty in the neutron star radii. This new term can be possibly due to the exchange of the weakly interacting light U-boson with appropriate in-medium parameters, which does not compromise the success of the conventional nuclear models. The validity of this new scheme will be tested eventually by more precise measurements of neutron star radii.Comment: EPJA (2015) in pres

Neutron-skin thickness of finite nuclei in relativistic mean-field models with chiral limits

We study several structure properties of finite nuclei using relativistic mean-field Lagrangians constructed according to the Brown-Rho scaling due to the chiral symmetry restoration at high densities. The models are consistent with current experimental constraints for the equations of state of symmetric matter at both normal and supra-normal densities and of asymmetric matter at sub-saturation densities. It is shown that these models can successfully describe the binding energies and charge radii of finite nuclei. Compared to calculations with usual relativistic mean-field models, these models give a reduced thickness of neutron skin in ^{208}Pb between 0.17 fm and 0.21 fm. The reduction of the predicted neutron skin thickness is found to be due to not only the softening of the symmetry energy but also the scaling property of $\rho$ meson required by the partial restoration of chiral symmetry.Comment: Accepted version to appear in PRC (2007

Large-mass neutron stars with hyperonization

Within a density-dependent relativistic mean-field model using in-medium meson-hadron coupling constants and meson masses, we explore effects of in-medium hyperon interactions on properties of neutron stars. It is found that the hyperonic constituents in large-mass neutron stars can not be simply ruled out, while the recently measured mass of the millisecond pulsar J1614-2230 can constrain significantly the in-medium hyperon interactions. Moreover, effects of nuclear symmetry energy on hyperonization in neutron stars are also discussed

Effects of medium-induced ρ−ω\rho-\omega meson mixing on the equation of state in isospin-asymmetric nuclear matter

We reexamine effects of the $\rho-\omega$ meson mixing mediated by nucleon polarizations on the symmetry energy in isospin-asymmetric nuclear matter. Taking into account the rearrangement term neglected in previous studies by others, we evaluate the $\rho-\omega$ mixing angle in a novel way within the Relativistic Mean-Field Models with and without chiral limits. It is found that the symmetry energy is significantly softened at high densities contrary to the finding in earlier studies. As the first step of going beyond the lowest-order calculations, we also solve the RPA equation for the $\rho-\omega$ mixing. In this case, it is found that the symmetry energy is not only significantly softened by the $\rho-\omega$ mixing at supra-saturation densities, similar to the lowest-order $\rho-\omega$ mixing, but interestingly also softened at subsaturation densities. In addition, the softening of the symmetry energy at subsaturation densities can be partly suppressed by the nonlinear self-interaction of the $\sigma$ meson.Comment: Significant changes made. Accepted version to appear in PRC (2009