Last year, 4,000 households with incomes over a million dollars owed no federal income tax whatsoever, according to Tax Policy Center estimates.
What's more, of the top 400 federal tax returns with the highest adjusted gross incomes in 2008, 30 had an effective tax rate of less than 10%, noted Mark Luscombe, the principal federal tax analyst at CCH.
The difference is that the rich use a broader array of tax-preferred investments, such as partnerships. Or they may invest in dividend-paying foreign stocks and can claim a foreign tax credit for the tax withheld from them by the foreign government.
Billionaires with 1% tax rates - Yahoo! Finance