In a special issue of the Bulletin for International Taxation, Professor Johanna Hey revisits an old classic of International Tax Law, the so-called "Single Tax Principle". The article examines its content, questions whether it can properly be regarded as a "principle" at all, explores its relationship to other established principles, and considers which solutions derived from the STP can be implemented in a fragmented international tax landscape.
A draft of the article was presented at the engaging interdisciplinary conference "Bulding Blocks of an International Tax Order" held in Munich from 15 to 16 December 2025 organized by the Max Planck Institute for Tax Law and Public Finance.
For an even deeper insight into the current debate, we also highly recommend reading the thoughtful comments by Professor Hey's esteemed colleague Professor Daniel Shaviro published in the same issue.
