Yeah the new 75% income tax bracket in France really is putting the Laffer curve theory to the test. Will be very interesting to see how it pans out. I'm sure socialist governments elsewhere in Europe is following this grand experiment closely.
http://www.taxpolicycenter.org/taxfacts/displayafact.cfm?Doc...
There is also a rather important paragraph at the bottom that I think you missed.
> "This table contains a number of simplifications and ignores a number of factors, such as a maximum tax on earned income of 50 percent when the top rate was 70 percent and the current increase in rates due to income-related reductions in value of itemized deductions. Perhaps most importantly it ignores the large increases in percentage of returns that were subject to the top rate".
The US tax code is so complicated you can't just look at some percentage and come to any sort of accurate conclusion. I would say the main factor in how much a given person pays in taxes depends mostly on their accountant.
You should also take into account most of the world was in shambles was when the war ended which gave the US a huge economic advantage.
Do you have any doubt that with the paper accounting of the 50's it was significantly easier to evade paying taxes? Do you really think anyone actually paid 70%?