Moreover, many of the roughly 650,000 filers with small-business income who face one of the top two tax rates are merely passive investors who have nothing to do with running the business. This is because the Tax Policy Center data cited above use the Treasury Department’s relatively broad definition of “small business.” Under the Treasury definition, for example, the $84 of income President Bush received in 2001 from a passive investment in an oil and gas company7 made him a “small-business owner.” About 35 percent of “small-business owners” with incomes above $200,000, and about 58 percent of “small-business owners” with incomes over $1 million, received some or all of their business income in the form of passive investments. The Treasury definition also counts as “small-business income” the fees that CEOs are paid for sitting on corporate boards.
In short, few small businesses see any benefit from reductions in the top two income tax rates. The imagined impact on small businesses is a poor justification for extending the current top two rates, which would increase the deficit by $450 billion over the next ten years.
http://www.cbpp.org/files/8-29-08tax.pdf