With a 15% rate? Individual and corporate income tax, the capital gains tax, the estate and gift taxes, and non-trust-fund excise taxes.
I don't know how much money the government collects from the corporate income tax, so I don't know what the effect would be.
From the 2004 budget as percentage of GDP
Individual income tax 7.0%
Corporate income tax 1.6%
Excise taxes 0.6%
Estate taxes 0.2%
Deficit 4.9%
http://www.cbo.gov/showdoc.cfm?index=1821&sequence=0That means that to keep the current deficit, 63% of the GDP has to be taxed at 15%. That's probably too high, since they exclude investments from the tax.
To close the deficit, too 95% of the GDP has to be taxed at 15%.
It's going to have to be a lot higher than 15%.