European taxes have long been debated for their potential role as barriers to increased investment and welfare. The discussion has often circulated around the size of the tax bases and the magnitude of the tax rate. In this book we argue that in the taxation context the European Union (EU) is at a cross-road facing strong forces pushing it into two polar positions. One of these is the scenario with all welfare provided by the national regime and financed by taxes collected entirely by national authorities. The other extreme is the situation where all welfare is - fered at an EU level financed entirely by taxes collected at that level. The two forces pressing the tax situation into one of these two poles are spelt tax compe- tion and welfare arbitrage. The research question addressed in this book covers the existence of a potential steady state in between these to poles. Our basic - pothesis is that their might be such a steady state due to the immobility of some tax bases and where the taxation of these bases have no externalities affecting - vestment. We argue that the very complex tax structures of Europe and the tax - certainty facing investors in Europe need to be addressed in a comprehensive way.