734 research outputs found
Tax Incentives and Household Portfolios: A Panel Data Analysis
This paper investigates the responsiveness of household portfolios to tax incentives by exploiting a substantial tax reform that altered after-tax returns and cost of debt for a large number of households. An extraordinary panel data set that covers two years before and after the reform is used for the analysis. Our empirical findings suggest that households reshuffle their balance sheets in the case of a partial deductibility phase-out. In particular, heavily taxed, interest-bearing assets are used to pay off mortgage debt. Furthermore, we find that taxes have a significant impact on the structure of household portfolios even after controlling for unobserved heterogeneity.Household portfolios, taxation, panel data, natural experiment
Strong-field approximation for Coulomb explosion of H_2^+ by short intense laser pulses
We present a simple quantum mechanical model to describe Coulomb explosion of
H by short, intense, infrared laser pulses. The model is based on the
length gauge version of the molecular strong-field approximation and is valid
for pulses shorter than 50 fs where the process of dissociation prior to
ionization is negligible. The results are compared with recent experimental
results for the proton energy spectrum [I. Ben-Itzhak et al., Phys. Rev. Lett.
95, 073002 (2005), B. D. Esry et al., Phys. Rev. Lett. 97, 013003 (2006)]. The
predictions of the model reproduce the profile of the spectrum although the
peak energy is slightly lower than the observations. For comparison, we also
present results obtained by two different tunneling models for this process.Comment: 8 pages, 4 figure
Approximate polynomial structure in additively large sets
We show that any subset of the natural numbers with positive logarithmic Banach
density contains a set that is within a factor of two of a geometric progression,
improving the bound on a previous result of the authors. Density conditions on
subsets of the natural numbers that imply the existence of approximate powers of
arithmetic progressions are developed and explore
Grammatikkens rolle i fremmedsprogsundervisning pÄ gymnasiet og universitetet
Denne artikel har til formÄl at diskutere tilrettelÊggelsen af grammatikundervisningen i fremmedsprogene pÄ gymnasie- og universitetsniveau. PÄ baggrund af resultater fra to empiriskeundersÞgelser, som fokuserer pÄ elevers/studerendes og underviseres antagelser om grammatik, pÄpeger vi nÞdvendigheden af et forstÊrket fokus pÄ fagdidaktik og en gentÊnkning afgrammatikkens rolle i sprogundervisningen
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