According to Neal Boortz's and Rep. John Linder's book The Fair Tax, there could be as much as $10 trillion in non-U.S. financial accounts. Impementing the Fair Tax would allow these trillions of dollars to flood the U.S. economy, which would promote growth. Not only would growth occur, but every citizen (whether or not they presently pay income taxes), every tourist and resident, legal and illegal,would contribute, because the Fair Tax is a consumption tax.
The benefits of the Fair Tax are too numerous to list here. I am not an economist nor an expert on all things financial. However, I do see the need for simplifying the U.S tax code, and the Fair Tax is the best way I have seen to accomplish this simplification. Anyone with questions about this tax to read Boortz's and Linder's book and decide for themselves.