Given this possibility of simple exit from any and all of the European tax systems (and such exit does not require that one stays in the EU either) the theoretical peak of the Laffer Curve is lower in Europe than it is in the US. Where such exit is very much more difficult.

FORBES: Why France's 75% Income Tax Rate Is Going To Be So Disastrous

When this curve plateaus and begins to decline, top talent desperately attempts to find the exit door.

FORBES: 6 Reasons Your Top Talent Won't Leave You