Cain mum about those giving him economic advice

Republican presidential candidate Herman Cain is quick to discuss his economic plan. But he isn't saying just who helped him create it.

Cain calls it the 9-9-9 plan. It would set a corporate flat tax at 9 percent and a personal flat tax at 9 percent, and establish a 9 percent national sales tax. The payroll tax, the estate tax and the tax on capital gains would be eliminated.

He was asked on "Fox News Sunday" who helped him develop the plan. Cain said he isn't at liberty to identify anyone but the chairman of his economic advisers.

Cain says the others are well-known business owners, but he doesn't want to compromise their confidentiality by naming them publicly.

The Cain campaign didn't respond to an Associated Press request for information.