"What we are talking about here … is the difference between the Roth IRA, where you do pay the taxes up front, and the regular IRA, where you pay them later," says Dr. Walden, a faculty member in the College of Agriculture and Life Sciences.

"Well, a couple ways to look at this: One depends on the tax rate. For example, if you thought your tax rate was going to be higher today, then you would not want to pay the taxes now. You would want to defer them," he says. "And the opposite if you thought the tax rate was going to be lower.

"But what if you thought your tax rate –- and, of course, this is very hard for anyone to know -– what if you thought, 'Well I’m going to assume my tax rate is going to be the same in retirement as now.' Then the question becomes, 'Well, which is better?'

"And actually many economists and financial people think the Roth is actually better, because if you don’t prepay your taxes, so to speak, and you have some money to invest outside of the IRA, the question becomes, could you invest it at a rate that is as good as the rate that you are getting inside the IRA?

"If the answer is no, then you are actually better off going ahead and prepaying the taxes and taking the Roth IRA.

"Bottomline here -- ... if this sounds confusing -- is that many investment experts say if you are going to do an IRA, go ahead and take the Roth IRA where you prepay taxes."