On iterative performance of LDPC and Root-LDPC codes over block-fading channels

This paper presents our investigation on iterativedecoding performances of some sparse-graph codes on block-fading Rayleigh channels. The considered code ensembles are standard LDPC codes and Root-LDPC codes, first proposed in and shown to be able to attain the full transmission diversity. We study the iterative threshold performance of those codes as a function of fading gains of the transmission channel and propose a numerical approximation of the iterative threshold versus fading gains, both both LDPC and Root-LDPC codes.Also, we show analytically that, in the case of 2 fading blocks,the iterative threshold root of Root-LDPC codes is proportional to (α1 α2)1, where α1 and α2 are corresponding fading gains.From this result, the full diversity property of Root-LDPC codes immediately follows.

Gender gaps in performance: Evidence from young lawyers

This paper documents and studies the gender gap in performance among associatelawyers in the United States. Unlike most high-skilled professions, the legal professionhas widely-used objective methods to measure and reward lawyers' productivity: thenumber of hours billed to clients and the amount of new-client revenue generated. Wefind clear evidence of a gender gap in annual performance with respect to bothmeasures. Male lawyers bill ten-percent more hours and bring in more than double thenew-client revenue. We show that the differential impact across genders in the presenceof young children and the differences in aspirations to become a law-firm partneraccount for a large part of the difference in performance. These performance gaps haveimportant consequences for gender gaps in earnings. While individual and firmcharacteristics explain up to 50 percent of earnings gap, the inclusion of performancemeasures explains most of the remainder.