Glass Ceiling or Sticky Floor? Examining the Gender Pay Gap across the Wage Distribution in Urban China, 1987-2004

Using 1987, 1996, and 2004 data, we show that the gender pay gap in the Chinese urban labor market has increased across the wage distribution, and the increase was greater at the lower quantiles. We interpret this as evidence of the “sticky floor” effect.We use the reweighting and recentered influence function projection method proposed by Firpo, Fortin, Lemieux (2005) to decompose gender pay differentials across the wage distribution. We find that the gender differences in the return to labor market characteristics, also known as the “discrimination effect” or “unexplained gender pay gap”, contribute most to the increase in the overall gender pay gap. The Firpo, Fortin, and Lemieux method allows us to further decompose the gender pay gap into the contribution of each individual variable. We find that the “sticky floor” effect may be associated with a particularly low paid group of female production workers with relatively less education working in non-state owned enterprises.glass ceiling; sticky floor; gender pay gap; wage distribution; Influence Function

Miniature High-Sensitivity High-Temperature Fiber Sensor with a Dispersion Compensation Fiber-Based Interferometer

A miniature high-sensitivity, high-temperature fiber sensor with an interferometer based on a bare small-core-diameter dispersion compensation fiber (DCF) is reported. The sensing head is a single-mode-fiber (SMF) DCF configuration formed by a 4 mm long bare DCF with one end connected to the SMF by a fusion splicing technique and the other end cleaved. Due to the large mode index difference and high thermo-optic coefficient induced by two dominative interference modes, a miniature high-temperature fiber sensor with a high sensitivity of 68.6 pm/°C is obtained by monitoring the wavelength shift of the interference spectrum. This type of sensor has the features of small size, high sensitivity, high stability, simple structure, and low cost

Decomposition of Changes in Earnings Inequality in China: A Distributional Approach

Using the nationwide household data, this study examines the changes in the Chinese urban income distributions from 1987 to 1996 and from 1996 to 2004, and investigates the causes of these changes. The Oaxaca-Blinder decomposition method is applied to decomposing the mean earnings increases, and the Firpo-Fortin-Lemieux method based upon a recentered influence function is used to decompose the changes in the income distribution and the inequality measures such as the variance and the 10-90 ratio. The decomposition results show that the wage structure effects such as the widened gender pay gap, the increasing return to college education, and the widened gap in the return to different industries, ownership, and regions, have contributed to most of the overall increases in income inequality. During the different time periods, 1987-1996 and 1996-2004, the impacts of these factors vary at the different points (e.g. the lower half or upper half) of distribution.Earnings inequality; Unconditional Quantile Regressions; Earnings distribution; Decomposition

Quantum Decoherence with Holography

Quantum decoherence is the loss of a system's purity due to its interaction with the surrounding environment. Via the AdS/CFT correspondence, we study how a system decoheres when its environment is a strongly-coupled theory. In the Feynman-Vernon formalism, we compute the influence functional holographically by relating it to the generating function of Schwinger-Keldysh propagators and thereby obtain the dynamics of the system's density matrix. We present two exactly solvable examples: (1) a straight string in a BTZ black hole and (2) a scalar probe in AdS$_5$. We prepare an initial state that mimics Schr\"odinger's cat and identify different stages of its decoherence process using the time-scaling behaviors of R\'enyi entropy. We also relate decoherence to local quantum quenches, and by comparing the time evolution behaviors of the Wigner function and R\'enyi entropy we demonstrate that the relaxation of local quantum excitations leads to the collapse of its wave-function.Comment: 55 pages, 13 figures; v2 47 pages & 13 figs, minor revision to match published versio

Exact Cosmological Solutions of f(R)f(R) Theories via Hojman Symmetry

Nowadays, $f(R)$ theory has been one of the leading modified gravity theories to explain the current accelerated expansion of the universe, without invoking dark energy. It is of interest to find the exact cosmological solutions of $f(R)$ theories. Besides other methods, symmetry has been proved as a powerful tool to find exact solutions. On the other hand, symmetry might hint the deep physical structure of a theory, and hence considering symmetry is also well motivated. As is well known, Noether symmetry has been extensively used in physics. Recently, the so-called Hojman symmetry was also considered in the literature. Hojman symmetry directly deals with the equations of motion, rather than Lagrangian or Hamiltonian, unlike Noether symmetry. In this work, we consider Hojman symmetry in $f(R)$ theories in both the metric and Palatini formalisms, and find the corresponding exact cosmological solutions of $f(R)$ theories via Hojman symmetry. There exist some new solutions significantly different from the ones obtained by using Noether symmetry in $f(R)$ theories. To our knowledge, they also have not been found previously in the literature. This work confirms that Hojman symmetry can bring new features to cosmology and gravity theories.Comment: 16 pages, revtex4; v2: discussions added, Nucl. Phys. B in press; v3: published version. arXiv admin note: text overlap with arXiv:1505.0754