Tax Specialist Martin Sullivan: Romney Tax Plan Is 'Not Mathematically Possible'

Another economist has joined the chorus of analysts saying that Mitt Romney's tax plan doesn't add up.

"I like tax reform. I want to broaden the base. It's something I've devoted my life to," Martin A. Sullivan, chief economist at Tax Analysts, told The New York Times. "I welcome Gov. Romney and the Republicans' strong push, but the plan doesn't work out. It's not mathematically possible."

Sullivan told the NYT that the Tax Policy Center, which found that Romney's tax plan is mathematically impossible, has it right. The article noted that it's not only Sullivan that's convinced by the Tax Policy Center paper. Economists from all sides of the political spectrum -- including from the conservative American Enterprise Institute -- find its claims to be trustworthy.

Other economists and pundits that say that Romney's plan is mathematically impossible include Mark Zandi, chief economist at Moody's Analytics, and conservative writer David Frum.

Romney has promised to slash marginal tax rates by 20 percent and cut taxes on investment income without raising taxes on the middle class or increasing the deficit. But the Tax Policy Center found in a recent analysis that accomplishing all of those promises at the same time would be mathematically impossible. Romney suggested capping deductions at $25,000 per family during the second presidential debate, but the think tank found that even with this modification, Romney's tax plan still would blow a $3.7 trillion hole in the deficit over the next 10 years.

Romney also promised at the third presidential debate that he would balance the budget within eight to 10 years. In response, Harvard economist Larry Summers, a former top economic adviser to President Barack Obama, told The Huffington Post on Tuesday that Romney's budget plan is "alchemy."

"Lead cannot be turned into gold. Two plus two cannot equal five," Summers told HuffPost. "And 20 percent across-the-board tax cuts cannot be squared with balanced budgets without raising middle-class taxes or eviscerating government."