Entry, Exit and the Dynamics of Productivity Growth in Chinese Manufacturing Industry

In this paper we have attempted to examine aspects of the competitive selection process, firms’ entry, survival and exit, in an important sector of Chinese manufacturing, looking in particular for changes resulting from the latest stage of reform, dubbed the transition to the “socialist market economy”. These dynamic processes may be becoming increasingly important for the continuing growth of manufacturing, as the agricultural sector as a source of surplus labour begins to decline.Entry, Exit, Survival, Productivity, Economic Reform, Chinese Enterprises

The challenge for single field inflation with BICEP2 result

The detection of B-mode power spectrum by the BICEP2 collaboration constrains the tensor-to-scalar ratio $r=0.20^{+0.07}_{-0.05}$ for the lensed-$\Lambda$CDM model. The consistency of this big value with the {\em Planck} results requires a large running of the spectral index. The large values of the tensor-to-scalar ratio and the running of the spectral index put a challenge to single field inflation. For the chaotic inflation, the larger the value of the tensor-to-scalar ratio is, the smaller the value of the running of the spectral index is. For the natural inflation, the absolute value of the running of the spectral index has an upper limit.Comment: 4 figures, 3 pages, some references added, PLB in pres

On the effect of the degeneracy between w_0 and w_a

The dynamics of scalar fields as dark energy is well approximated by some general relations between the equation of state parameter $w(z)$ and the fraction energy density $\Omega_\phi$. Based on the approximation, for slowly-rolling scalar fields, we derived the analytical expressions of $w(z)$ which reduce to the popular Chevallier-Polarski-Linder parametrization with explicit degeneracy relation between $w_0$ and $w_a$. The models approximate the dynamics of scalar fields well and help eliminate the degeneracies among $w_a$, $w_0$ and $\Omega_{m0}$. With the explicit degeneracy relations, we test their effects on the constraints of cosmological parameters. We find that: (1) The analytical relations between $w_0$ and $w_a$ for the two models are consistent with observational data; (2) The degeneracies have little effect on $\Omega_{m0}$; (3) The $1\sigma$ error of $w_0$ was reduced about 30% with the degeneracy relations.Comment: add discussions on the reconstruction of thawing potentials, Eur. Phys. J. C in pres

Stabilizing Non-Hermitian Systems by Periodic Driving

The time evolution of a system with a time-dependent non-Hermitian Hamiltonian is in general unstable with exponential growth or decay. A periodic driving field may stabilize the dynamics because the eigenphases of the associated Floquet operator may become all real. This possibility can emerge for a continuous range of system parameters with subtle domain boundaries. It is further shown that the issue of stability of a driven non-Hermitian Rabi model can be mapped onto the band structure problem of a class of lattice Hamiltonians. As an application, we show how to use the stability of driven non-Hermitian two-level systems (0-dimension in space) to simulate a spectrum analogous to Hofstadter's butterfly that has played a paradigmatic role in quantum Hall physics. The simulation of the band structure of non-Hermitian superlattice potentials with parity-time reversal symmetry is also briefly discussed

Reform and Competitive Selection in China: An Analysis of Firm Exits

This paper considers aspects of the competitive selection process in China - firm entry, survival, and exit - in an important sector of manufacturing, looking in particular for changes resulting from the latest stage of reforms. Using industry survey data from a province in North-East China, we find substantial differences in the process between ownership types. By conducting a simple decomposition of the aggregate productivity growth and exploring the determinants of firm’s exit using a hazard rate model, we observe a substantial rate of churning of enterprises in the sector, and find that the competitive selection processes operate, for small and collectively owned enterprises (COEs), in a manner consistent with a private market economy. In contrast, such processes appear not to be functioning for state owned enterprises (SOEs). We conclude that competitive selection in China is not providing a sufficiently strong substitute for corporate governance based on ownership.Competition; Exit; Productivity, Hazard Models

The Phase-space analysis of scalar fields with non-minimally derivative coupling

We perform a dynamical analysis for the exponential scalar field with non-minimally derivative coupling. For the quintessence case, the stable fixed points are the same with and without the non-minimally derivative coupling. For the phantom case, the attractor with dark energy domination exists for the minimal coupling only. For the non-minimally derivative coupling without the standard canonical kinetic term, only the de-Sitter attractor exists, and the dark matter solution is unstable.Comment: v2, minor correction, EPJC in pres