“russia have a 13% flat tax?!?!!!!”
Yeppers, they do.
If you look at the story of the story of Joseph and his rise to becoming the viceroy of Egypt you will see that he suggests a 20% tax on crops. This was an actual lowering of the tax there at that time.
Even today non-collectivist economists agree that it should be not more than 19 or 20 percent.
If the total tax burden on the everyone could be not more than 20% the US economy would skyrocket.
And I believe that "tax" was only during a time of record setting crop growth, not during the lean years. :)