CLARKONOMICS: Just days ago, Clark shared news that many people are beginning to feel more confidence about the economy and their own situations. Yet at the same time, people with money in the stock market have been more nervous lately as the Dow dances at, above and below 10,000.

Where exactly is the worry coming from? There's concern about the PIGS -- Portugal, Ireland, Greece and Spain -- and the fiscal hot water they're in. Greece is running huge budget deficits, and Spain's unemployment is over 20 percent right now.

That has created worry about the possibility of bailouts for entire European countries -- not just individual banks.

Here in the United States, we are beginning to see signs of a recovery, though jobs are still far from abundant. So the worry about the other shoe dropping now centers on PIGS.

Yet Clark sees more reasons for optimism than pessimism. Considering what we've been through, we're in better shape than he might have expected.

If you are a stock investor, it's important to remember your horizons. It's too risky to be in the stock market if you need your money in the next year or two. Yet if you won't need it until retirement in 20 or 30 years, there's no reason to be unnecessarily cautious.