Assimilation, labour market experience, and earnings profiles of temporary and permanent immigrant workers in germany

We test the assimilation hypothesis as initially proposed by Chiswick (1978) by making. use of a rich panel dataset for Germany which allows us to control for unobserved population heterogeneity and potential selectivity bias arising from an individual's re-migration decision and employment behaviour. To take into account the institutional aspects of the German guest-worker system we use information on an immigrant's expected duration of stay in Germany to distinguish between temporary and permanent migrants and to test for differences in earnings/experience profiles with respect to a foreigner's expected duration of stay. We find that years of schooling in Germany have a strong positive effect on earnings, that earnings/experience profiles of guest-workers differ by expected duration of stay, and that the renumeration of labour market experience in Germany is higher for natives than for most foreigners. The assimilation hypothesis is therefore not supported by the evidence for Germany. --

Protograph-Based LDPC Code Design for Shaped Bit-Metric Decoding

A protograph-based low-density parity-check (LDPC) code design technique for bandwidth-efficient coded modulation is presented. The approach jointly optimizes the LDPC code node degrees and the mapping of the coded bits to the bit-interleaved coded modulation (BICM) bit-channels. For BICM with uniform input and for BICM with probabilistic shaping, binary-input symmetric-output surrogate channels for the code design are used. The constructed codes for uniform inputs perform as good as the multi-edge type codes of Zhang and Kschischang (2013). For 8-ASK and 64-ASK with probabilistic shaping, codes of rates 2/3 and 5/6 with blocklength 64800 are designed, which operate within 0.63dB and 0.69dB of continuous AWGN capacity for a target frame error rate of 1e-3 at spectral efficiencies of 1.38 and 4.25 bits/channel use, respectively.Comment: 9 pages, 10 figures. arXiv admin note: substantial text overlap with arXiv:1501.0559

Ultra-Sparse Non-Binary LDPC Codes for Probabilistic Amplitude Shaping

This work shows how non-binary low-density parity-check codes over GF($2^p$) can be combined with probabilistic amplitude shaping (PAS) (B\"ocherer, et al., 2015), which combines forward-error correction with non-uniform signaling for power-efficient communication. Ultra-sparse low-density parity-check codes over GF(64) and GF(256) gain 0.6 dB in power efficiency over state-of-the-art binary LDPC codes at a spectral efficiency of 1.5 bits per channel use and a blocklength of 576 bits. The simulation results are compared to finite length coding bounds and complemented by density evolution analysis.Comment: Accepted for Globecom 201

Bit-Metric Decoding of Non-Binary LDPC Codes with Probabilistic Amplitude Shaping

A new approach for combining non-binary low-density parity-check (NB-LDPC) codes with higher-order modulation and probabilistic amplitude shaping (PAS) is presented. Instead of symbol-metric decoding (SMD), a bit-metric decoder (BMD) is used so that matching the field order of the non-binary code to the constellation size is not needed, which increases the flexibility of the coding scheme. Information rates, density evolution thresholds and finite-length simulations show that the flexibility comes at no loss of performance if PAS is used.Comment: Accepted for IEEE Communication Letter

Testing for state dependence effects in a dynamic model of male unemployment behaviour

A dynamic random effects probit model is estimated on the first six waves of the German Socio-Economic Panel to test for state dependence effects in male unemployment behaviour. Estimation of the model is based on the marginal likelihood approach. In the model an individual's unemployment probability at a given point in time within the period 1985 - 1989 depends on his labour force status in the previous period and on the cumulated duration of past unemployment. Controlling for observed and unobserved population heterogeneity, we show that there are strong state dependence effects in individual unemployment dynamics with respect to both the incidence and the duration of an individual's past unemployment. These results are compatible with the 'scar theory' of unemployment which holds that an individual's previous unemployment experience may have long-term effects because it induces a depreciation of human capital and/or acts as a screening device in employers hiring decisions. --

A note on adjoint error estimation for one-dimensional stationary balance laws with shocks

We consider one-dimensional steady-state balance laws with discontinuous solutions. Giles and Pierce realized that a shock leads to a new term in the adjoint error representation for target functionals.This term disappears if and only if the adjoint solution satisfies an internal boundary condition. Curiously, most computer codes implementing adjoint error estimation ignore the new term in the functional, as well as the internal adjoint boundary condition. The purpose of this note is to justify this omission as follows: if one represents the exact forward and adjoint solutions as vanishing viscosity limits of the corresponding viscous problems, then the internal boundary condition is naturally satisfied in the limit