Di Bao : a guaranteed minimum income in urban China?

Concerns about incentives and targeting naturally arise when cash transfers are used to fight poverty. The authors address these concerns in the context of China's Di Bao program, which uses means-tested transfers to try to assure that no registered urban resident has an income below a stipulated poverty line. There is little sign in the data of poverty traps due to high benefit withdrawal rates. Targeting performance is excellent by various measures. Di Bao appears to be better targeted than any other program in the developing world. However, all but one measure of targeting performance is found to be uninformative, or even deceptive, about impacts on poverty. The authors find that the majority of the poor are not receiving help, even with a generous allowance for measurement errors. While on paper, Di Bao would eliminate urban poverty, it falls well short of that ideal in practice.Services&Transfers to Poor,Poverty Monitoring&Analysis,Poverty Impact Evaluation,Inequality,Poverty Diagnostics

Outflow and hot dust emission in high redshift quasars

Correlations of hot dust emission with outflow properties are investigated, based on a large z~2 non-broad absorption lines quasar sample built from the Wide-field Infrared Survey and the Sloan Digital Sky Survey data releases. We use the near infrared slope and the infrared to UV luminosity ratio to indicate the hot dust emission relative to the emission from the accretion disk. In our luminous quasars, these hot dust emission indicators are almost independent of the fundamental parameters, such as luminosity, Eddington ratio and black hole mass, but moderately dependent on the blueshift and asymmetry index (BAI) and full width at half-maximum (FWHM) of CIV lines. Interestingly, the latter two correlations dramatically strengthen with increasing Eddington ratio. We suggest that, in high Eddington ratio quasars, CIV regions are dominated by outflows so the BAI and FWHM(CIV) can reliably reflect the general properties and velocity of outflows, respectively. While in low Eddington ratio quasars, CIV lines are primarily emitted by virialized gas so the BAI and FWHM(CIV) become less sensitive to outflows. Therefore, the correlations for the highest Eddington ratio quasars are more likely to represent the true dependence of hot dust emission on outflows and the correlations for the entire sample are significantly diluted by the low Eddington ratio quasars. Our results show that an outflow with a large BAI or velocity can double the hot dust emission on average. We suggest that outflows either contain hot dust in themselves or interact with the dusty interstellar medium or torus.Comment: 14 page, 4 figures, accepted for publication in ApJ

A Simplified Min-Sum Decoding Algorithm for Non-Binary LDPC Codes

Non-binary low-density parity-check codes are robust to various channel impairments. However, based on the existing decoding algorithms, the decoder implementations are expensive because of their excessive computational complexity and memory usage. Based on the combinatorial optimization, we present an approximation method for the check node processing. The simulation results demonstrate that our scheme has small performance loss over the additive white Gaussian noise channel and independent Rayleigh fading channel. Furthermore, the proposed reduced-complexity realization provides significant savings on hardware, so it yields a good performance-complexity tradeoff and can be efficiently implemented.Comment: Partially presented in ICNC 2012, International Conference on Computing, Networking and Communications. Accepted by IEEE Transactions on Communication