Complex Word Identification: Challenges in Data Annotation and System Performance

This paper revisits the problem of complex word identification (CWI) following up the SemEval CWI shared task. We use ensemble classifiers to investigate how well computational methods can discriminate between complex and non-complex words. Furthermore, we analyze the classification performance to understand what makes lexical complexity challenging. Our findings show that most systems performed poorly on the SemEval CWI dataset, and one of the reasons for that is the way in which human annotation was performed.Comment: Proceedings of the 4th Workshop on NLP Techniques for Educational Applications (NLPTEA 2017

Deformation of polymer films by bending forces

We study the deformation of nano--scale polymer films which are subject to external bending forces by means of computer simulation. The polymer is represented by a generalized bead--spring--model, intended to reproduce characteristic features of n--alkanes. The film is loaded by the action of a prismatic blade which is pressed into the polymer bulk from above and a pair of columns which support the film from below. The interaction between blade and support columns and the polymer is modelled by the repulsive part of a Lennard-Jones potential. For different system sizes as well as for different chainlengths, this nano--scale experiment is simulated by molecular dynamics methods. Our results allow us to give a first characterization of deformed states for such films. We resolve the kinetic and the dynamic stage of the deformation process in time and access the length scale between discrete particle and continuum mechanics behaviour. For the chainlengths considered here, we find that the deformation process is dominated by shear. We observe strangling effects for the film and deformation fluctuations in the steady state.Comment: 15 pages, 8 figure

Shifting the tax burden from labor to property: The case of Germany

Contrary to frequent recommendations of the public finance literature and international institutions, a persistently high tax wedge on labor is observed in Europe. At the same time, the scope for shifting taxes from labor to more growth-friendly revenue sources appears underused in many European countries. This motivates our simulation of a revenue-neutral property tax reform for Germany, a country in which tax receipts from land are particularly low. More precisely, we assess by how much social insurance contributions (SIC) can be reduced when Germany switches from its current property tax scheme based on outdated cadastral values to one based on market property values. In order to make such a simulation possible, we match property related information with the input dataset of EUROMOD, the tax-benefit simulation model for the EU. Our results suggest that the implicit tax rate on labor could be reduced from currently 37,2% to 36,5%. Furthermore, we simulate different scenarios of the SIC reduction. Redistributive effects of these different scenarios tend to be modest and depend crucially on the design of the SIC reduction

Taking the high road? Compliance with commuter tax allowances and the role of evasion spillovers

This paper provides evidence of evasion in the context of a widely used commuter tax allowance, and explores evasion spillovers as a determinant of the individual compliance decision. For this purpose, we exploit discontinuities in the commuter allowance scheme and employ a research design resting on a large panel of individual tax returns. We find that around 30 percent of all allowance claims are overstated and, consistent with deliberate tax evasion, we observe sharp reactions of taxpayers to thresholds where the allowance discretely jumps to a higher amount. Further, we use variation in job changes to uncover spillover effects from the work environment on the individual compliance decision. These effects appear to be asymmetric: Job changers moving to companies with a higher fraction of cheaters increase their cheating. In contrast, movers to companies with a lower fraction of cheaters tend not to alter their reporting behavior. We provide suggestive evidence that the spillover has more to do with an information environment, but can ultimately not reject other behavioral explanations such as asymmetric persistence of norms