ROBERT SIEGEL, HOST:
From NPR News, this is ALL THINGS CONSIDERED. I'm Robert Siegel.
MELISSA BLOCK, HOST:
And I'm Melissa Block. In the race for the Republican presidential nomination, Herman Cain is seeing a popularity spike. Another poll today, this time from CNN, has him essentially tied with Mitt Romney at the front of the pack. Herman Cain attributes much of his success to three numbers: 9-9-9.
HERMAN CAIN: Nine percent corporate business flat tax, 9 percent personal income flat tax, and a 9 percent national sales tax. And it will pass, Senator, because the American people want it to pass.
BLOCK: That's Herman Cain describing his tax plan at last week's GOP debate. As NPR's Tamara Keith reports, he wants to scrap the current system and start over.
TAMARA KEITH, BYLINE: First, a disclaimer: Cain's campaign hasn't released a ton of detail about the plan. The description of 9-9-9 on his website adds up to precisely 451 words, which is 39 more words than last week. Requests for further information from the campaign, and its chief economic adviser, got no response. But Cain, who used to be the CEO of Godfather's Pizza, defended the plan at last week's debate.
(SOUNDBITE OF REPUBLICAN PRESIDENTIAL DEBATE)
CAIN: It didn't come off a pizza box. No. It was well-studied and well-developed because it will replace the corporate income tax, the personal income tax, the capital gains tax, the death tax and most importantly, the payroll tax.
KEITH: All those taxes would go away, replaced by a three-layered system taxing business income, personal income and consumption - each at 9.1 percent. Gary Robbins is president of Fiscal Associates in Northern Virginia. He was hired by the campaign to do an independent analysis of the plan, and he doesn't speak for the campaign.
GARY ROBBINS: What he's trying to do is to broaden the base and lower the rate, and that's what these do. I guess I would have picked a different mix, maybe, and I might have done it a little bit differently than he did. But there's nothing wrong with what he said.
KEITH: Today, there are lots of exceptions and deductions - like the mortgage interest deduction, the child tax credit, and the earned income tax credit for low-income households. Cain would get rid of those, too. His only deduction would be for charitable contributions. Sales tax would apply to everything - milk, bread, medicine. The only things that wouldn't be taxed are used goods, like used cars and existing homes. Robbins says as a result, Cain's plan would be able to raise as much money as the current tax code.
ROBBINS: The thrust of what he said is correct - that you can, in fact, drive the rates way down if you're willing to allow all the special dispensations that we grant these days to go away.
KEITH: Robbins' written analysis, though, differs in significant ways from what is on Cain's website. Robbins assumes a tax break for all poor people, while the website doesn't. The Cain plan has sent some of the nation's top tax wonks into overdrive, analyzing what it would mean for taxpayers. Edward Kleinbard is a law professor at USC, and a former chief of staff for the main congressional tax committee. He just wrote a paper about 9-9-9. The take-home?
EDWARD KLEINBARD: The rich will find their tax bills going down, and the majority of working Americans would find their tax bills going up, quite substantially.
KEITH: He says under Cain's plan, a family earning $120,000 a year would see their after-tax disposable income drop by about $500.
KLEINBARD: Basically from that point down, most everybody is worse off. And the further down the income ladder you go, the extent to which a family is worse off, under the Cain plan, increases dramatically.
KEITH: For a family of four earning $50,000 a year, Kleinbard says the hit would be about $5,000 under the 9-9-9 plan. Cain told NPR last week they'd be better off, but several tax experts disagree. Roberton Williams, a senior fellow at the Tax Policy Center, says for the lowest-income Americans, the tax hit under 9-9-9 would be even more substantial.
ROBERTON WILLIAMS: There are 30 million people who currently pay neither the federal income tax nor federal payroll taxes, and those people would see a 9 percent tax on their income as well as a 9 percent tax on every dollar they spend. So for those people, it's definitely a large tax increase.
KEITH: On NBC's "Meet the Press" yesterday, Cain admitted that some people wouldn't be better off.
(SOUNDBITE OF TV SHOW, "MEET THE PRESS")
CAIN: Some people will pay more but most people would pay less, is my argument.
DAVID GREGORY: Who will pay more?
CAIN: Who will pay more? The people who spend more money on new goods.
KEITH: Economists say generally, people who make less money spend a larger share of their income on food and other essentials. Cain suggests that even if this is true, they can change their behavior and purchase more used items. Tamara Keith, NPR News.