Held Harmless by Higher Income Tax Rates?

In 2010, 45 percent of tax returns will either remit no federal income tax or receive a net tax refund. But this figure overstates the share of taxpayers who would be unaffected by higher income tax rates. Raising all rates by 1 percent would hold only 34 percent of tax returns harmless; others would either pay higher taxes or receive smaller net rebates.