Abstract: | These articles debate the pros and cons of the full income-splitting tax procedure. Ernst Niemeier defends this taxation scheme, because in his opinion it is not aimed at furthering families or children but making sure that a couple does not have to pay more taxes than two singles. He argues that there are constitutional reasons to treat equal incomes equally, which he refers to as “horizontal justice”. Furthermore, he rejects evidence of a negative labour supply effect on the second earner. A team of authors at the DIW find his argumentation not at all convincing. First, they say, determining tax justice or ability to pay is ultimately a political question and cannot be determined by scientists or the courts. Thus, a constitutional determination of marriage taxation on the existing full income-splitting procedure is excessive. Second, the empirical evidence of negative labour supply effects of full income splitting for the second earner can simply not be denied. Niemeier argues why such supply effects cannot exist. |