This paper is about “Capital in the Twenty-first Century” by Thomas Piketty. It identifies his central macroeconomic claims and examines them, arguing that the contentions are theoretically and empirically unwarranted.

Mirrlees' optimal income tax formula has never been proven rigorously, and it is hard to understand it in economic terms. We prove an analogous formula for an economy with finitely many persons. This is easy and allows a simple economic interpretation. Thereafter, Mirrlees' original formula is...

The article considers the splitting of income between spouses from an economic perspective. It argues that this provision does not privilege married couples but prohibits their discrimination.

The German Constitutional Court has obliged parliament to enact an income tax law which lets the subsistence level tax-exempt. This can be done, in principle, by using a basic allowance or a zero-rated bracket. The paper discusses these alternatives.

In Germany, commuting expenses have been deductible from the income tax base for a long time. Germany’s grand coalition has now restricted this deduction. The article analyses whether or not this was justified from an economic point of view. It is shown that, in the long run, the tax treatment...

Der Aufsatz untersucht Paul Kirchhofs Vorschlag eines Einkommensteuergesetzbuchs.