Das objektive Nettoprinzip als Rechtfertigungsmaßstab im Einkommensteuerrecht

The German income tax is based on the so-called objective net principle: It allows the deduction of work-related or business expenses and therefore only taxes the net income. But where does the legislator’s freedom to shape the rules on deduction end? Where are the immediate constitutional limits? On what grounds and to what extent does the legislator bind himself? These questions dominate the discussion on constitutional law and therefore the limits of tax policy.
More thoroughly than in previous expert literature, the author analyses constitutional status and scope of, and justification of exceptions to, the objective net principle. Beyond that, on the level of subconstitutional law, he states the extent of the legislator’s obligation to act consistently and the requirements to justify exceptions to the objective net principle. The results of the analysis conclude in a suggestion on how to systematically consolidate the income tax law.