How Much Is 'Enough' for Retirement?

When it comes to retirement, no nest egg is ever too big.

But with an economic crisis draining the life from 401(k)s, IRAs and pension plans, a lot of people are asking themselves if they can still afford to retire early, on time or at all.

Individuals "can still set any goal they want," says author and economist Ben Stein. "The question is, can they get to it?"

In recent years, it wasn't unusual for investors to recoup 8 percent or 9 percent annually from their retirement accounts, he says. "Those predictions are now off the table."

Now, our nation's financial predicament has many people challenging the assumptions they'd made about retirement.

"The real question is if retirement as a whole is still relevant," says Stein, author of "How to Ruin the United States of America." The recent economic crisis "has put a crowbar into people's retirement planning," he says. And it "calls into question whether a whole generation of Americans can retire. The result is that all bets are off."