Die Zinsschranke als Instrument zur Missbrauchsvermeidung und Steigerung der Eigenkapitalausstattung.

The general public thinks of tax law as a rather dry subject and the people concerned with it generally do not appear in a better light. There are reasons for justifiable doubts regarding this prejudice as shown by specialist articles on the actual amendment of the deductibility of interest for tax purposes, the so called Interest Barrier (Zinsschranke). When analyzing this core element of the corporate tax reform from 2008, finance and tax experts do not make use of their general objective vocabulary but rather use a lively and colorful wording to describe the provision regulated in Secs. 4h German Income Tax Act and 8a German Corporate Tax Act. They draw examples from such areas as zoology, meteorology, pyrotechnics, medicine, history and religion, calling the Interest Barrier »biting tiger«, »nice weather reform«, »loaded fuse«, »fire accelerant«, »lethal injection«, »guillotine« or even »mortal sin«. Further to the published articles, this dissertation focusses on the formation of the Interest Barrier, the analysis of its concept and especially on the examination of its compatibility with the constitutional standards in art. 3 and 14 of the German Constitution, central for taxation. In this regard, all objectives of the legislator as well as current empirical and economical results with respect to the effects of the Interest Barrier are taken into account. Not only the limits on taxation because of »choking« taxation affects under art. 14 of the German Constitution are considered but also current rulings of the second senate of the German Federal Constitutional Court on the proportionality of taxation. This dissertation aims to make a contribution towards the dogmatic understanding of the Interest Barrier.