Emigration and Wages: The EU Enlargement Experiment

The enlargement of the European Union provides a unique opportunity to study the impact of the lifting of migration restrictions on the migrant sending countries. With EU enlargement in 2004, 1.2 million workers from Eastern Europe emigrated to the UK and Ireland. I use this emigration wave to show that emigration significantly changed the wage distribution in the sending country, in particular between young and old workers. Using a novel dataset from Lithuania, the UK and Ireland for the calibration of a structural model of labor demand, I find that over the period of five years emigration increased the wages of young workers by 6%, while it had no effect on the wages of old workers. Contrary to the immigration literature, there is no significant effect of emigration on the wage distribution between high-skilled and low-skilled workers.emigration, EU enlargement, European integration, wage distribution

Efficient Wiener filtering without preconditioning

We present a new approach to calculate the Wiener filter solution of general data sets. It is trivial to implement, flexible, numerically absolutely stable, and guaranteed to converge. Most importantly, it does not require an ingenious choice of preconditioner to work well. The method is capable of taking into account inhomogeneous noise distributions and arbitrary mask geometries. It iteratively builds up the signal reconstruction by means of a messenger field, introduced to mediate between the different preferred bases in which signal and noise properties can be specified most conveniently. Using cosmic microwave background (CMB) radiation data as a showcase, we demonstrate the capabilities of our scheme by computing Wiener filtered WMAP7 temperature and polarization maps at full resolution for the first time. We show how the algorithm can be modified to synthesize fluctuation maps, which, combined with the Wiener filter solution, result in unbiased constrained signal realizations, consistent with the observations. The algorithm performs well even on simulated CMB maps with Planck resolution and dynamic range.Comment: 5 pages, 2 figures. Submitted to Astronomy and Astrophysics. Replaced to match published versio

ARKCoS: Artifact-Suppressed Accelerated Radial Kernel Convolution on the Sphere

We describe a hybrid Fourier/direct space convolution algorithm for compact radial (azimuthally symmetric) kernels on the sphere. For high resolution maps covering a large fraction of the sky, our implementation takes advantage of the inexpensive massive parallelism afforded by consumer graphics processing units (GPUs). Applications involve modeling of instrumental beam shapes in terms of compact kernels, computation of fine-scale wavelet transformations, and optimal filtering for the detection of point sources. Our algorithm works for any pixelization where pixels are grouped into isolatitude rings. Even for kernels that are not bandwidth limited, ringing features are completely absent on an ECP grid. We demonstrate that they can be highly suppressed on the popular HEALPix pixelization, for which we develop a freely available implementation of the algorithm. As an example application, we show that running on a high-end consumer graphics card our method speeds up beam convolution for simulations of a characteristic Planck high frequency instrument channel by two orders of magnitude compared to the commonly used HEALPix implementation on one CPU core while maintaining at typical a fractional RMS accuracy of about 1 part in 10^5.Comment: 10 pages, 6 figures. Submitted to Astronomy and Astrophysics. Replaced to match published version. Code can be downloaded at https://github.com/elsner/arkco

Fast calculation of the Fisher matrix for cosmic microwave background experiments

The Fisher information matrix of the cosmic microwave background (CMB) radiation power spectrum coefficients is a fundamental quantity that specifies the information content of a CMB experiment. In the most general case, its exact calculation scales with the third power of the number of data points N and is therefore computationally prohibitive for state-of-the-art surveys. Applicable to a very large class of CMB experiments without special symmetries, we show how to compute the Fisher matrix in only O(N^2 log N) operations as long as the inverse noise covariance matrix can be applied to a data vector in time O(l_max^3 log l_max). This assumption is true to a good approximation for all CMB data sets taken so far. The method takes into account common systematics such as arbitrary sky coverage and realistic noise correlations. As a consequence, optimal quadratic power spectrum estimation also becomes feasible in O(N^2 log N) operations for this large group of experiments. We discuss the relevance of our findings to other areas of cosmology where optimal power spectrum estimation plays a role.Comment: 4 pages, 1 figures. Accepted for publication in Astronomy and Astrophysics Letters. Replaced to match published versio

Using hybrid GPU/CPU kernel splitting to accelerate spherical convolutions

We present a general method for accelerating by more than an order of magnitude the convolution of pixelated functions on the sphere with a radially-symmetric kernel. Our method splits the kernel into a compact real-space component and a compact spherical harmonic space component. These components can then be convolved in parallel using an inexpensive commodity GPU and a CPU. We provide models for the computational cost of both real-space and Fourier space convolutions and an estimate for the approximation error. Using these models we can determine the optimum split that minimizes the wall clock time for the convolution while satisfying the desired error bounds. We apply this technique to the problem of simulating a cosmic microwave background (CMB) anisotropy sky map at the resolution typical of the high resolution maps produced by the Planck mission. For the main Planck CMB science channels we achieve a speedup of over a factor of ten, assuming an acceptable fractional rms error of order 1.e-5 in the power spectrum of the output map.Comment: 9 pages, 11 figures, 1 table, accepted by Astronomy & Computing w/ minor revisions. arXiv admin note: substantial text overlap with arXiv:1211.355

Does Emigration Benefit the Stayers? The EU Enlargement as a Natural Experiment. Evidence from Lithuania

The eastern enlargement of the European Union in 2004 triggered a large flow of migrant workers from the new member states to the UK and Ireland. This paper analyzes the impact of this migration wave on the real wages in the source countries. I consider the case of Lithuania, which had the highest share of emigrants relative to its workforce among all ten new member states. Using data from the Lithuanian Household Budget Survey and the Irish Census, I find that emigration had a significant positive effect on the wages of men who stayed in the country, but no such effect is visible for women. A percentage point increase in the emigration rate increases the real wage of men on average by 1%. Several robustness checks confirm this result.Emigration, Labor Mobility, EU Enlargement

Emigration and Wages: The EU Enlargement Experiment

This paper studies the impact of a large emigration wave on real wages in the source country. Following EU enlargement in 2004, a large share of the workforce of the Central and Eastern Europe emigrated to Western Europe. Using data from Lithuania for the calibration of a factor demand model I show that emigration had a significant short-run impact on real wages in the source country. In particular, emigration led to a change in the wage distribution between young and old workers. The wages of young workers increased by 6%, whereas the wages of old workers decreased by around 1%. On the contrary, I find no effect on the wage distribution between workers of different education levels.Emigration, EU Enlargement, European Integration, Wage Distribution

Does Emigration Benefit the Stayers? The EU Enlargement as a Natural Experiment. Evidence from Lithuania

The eastern enlargement of the European Union in 2004 triggered a large flow of migrant workers from the new member states to the UK and Ireland. This paper analyzes the impact of this migration wave on the real wages in the source countries. I consider the case of Lithuania, which had the highest share of emigrants relative to its workforce among all ten new member states. Using data from the Lithuanian Household Budget Survey and the Irish Census, I find that emigration had a significant positive effect on the wages of men who stayed in the country, but no such effect is visible for women. A percentage point increase in the emigration rate increases the real wage of men on average by 1\%. Several robustness checks confirm this result.Emigration, EU Enlargement, Labor Mobility

Emigration and Wages: The EU Enlargement Experiment

This paper studies the impact of a large emigration wave on real wages in the source country. Following EU enlargement in 2004, a large share of the workforce of the Central and Eastern Europe emigrated to Western Europe. Using data from Lithuania for the calibration of a factor demand model I show that emigration had a significant short-run impact on real wages in the source country. In particular, emigration led to a change in the wage distribution between young and old workers. The wages of young workers increased by 6%, whereas the wages of old workers decreased by around 1%. On the contrary, I find no effect on the wage distribution between workers of different education levels.Emigration, EU Enlargement, European Integration, Wage Distribution