Your VAT is up too 21%? Wholy sweet crap. We have a state by state sales tax, and it rarely gets above 8% and it is added on at the till so that we don't lose track of how much the tax is every time we buy something. And our highest tax rate is only 36%. We do phase out deductions as well so people like Bill Gates now pay all of that, unless they try and hide the money in the caymen islands or in a Swiss bank (regular readers will recal I hate the Swiss) and this is of course Illegal; and if you get caught you get to go to one of our lovley resort penitentiaries where you get to sleep in a room with 30 other nonviolent offenders in bunk beds and every one gets to watch when you take a crap, like summer camp but the doors lock from the outside.
The argument for a flat tax is it's simplicity. It always seems like a bad ideato try and do social policy with tax incentives.