According to a report in yesterday's New York Times, even Alan Greenspan is contemplating a future in which the Fed's short-term rate hikes -- steady as a metronome for roughly a year now -- have little ability to kick the tires on long-term rates. Indeed, the article suggests that those numbers might remain low for the foreseeable future and, perhaps, beyond.

So here's the $64,000 question: What should smart investors do in response?

In a word, nothing. In three more words, zero, zip, nada.

Remember a year or so ago, when everyone and his hot-stock-tipping uncle was predicting bad news for bonds because we were entering a "rising rate environment?" Well, here's a shocker: They were wrong. The bond market has done just fine, thank you very much, with the Lehman Brothers Aggregate Index up roughly 7% over the last 12 months.

The moral of the story -- beyond the fact that you should never pay attention to hot-stock-tipping uncles -- is that they don't call economics the dismal science for nothing. And macroeconomics is especially dismal, mainly because it's so easy to get wrong.

That said, the current sentiment about interest rates could give certain kinds of companies a near-term boost.

Financial concerns such as Bank of America (NYSE:BAC), Washington Mutual (NYSE:WM), and Countrywide Financial (NYSE:CFC) could benefit from the perception that the mortgage-lending business is likely to remain brisk. Homebuilders such as Centex (NYSE:CTX), Pulte Homes (NYSE:PHM), Lennar (NYSE:LEN), and Toll Brothers (NYSE:TOL) might ride that same notion to higher stock prices, too.

But I wouldn't bet on it.

Sentiment has a nasty habit of changing virtually overnight, and the best way to make investment decisions remains the automotive method: Lift the hood and kick the tires.

Indeed, if the price is right, all the aforementioned companies may very well be sound long-term propositions. But when it comes to making that call, Fools should let company fundamentals and valuations -- not macroeconomic forecasts -- be their guide.

Shannon Zimmerman heads up the Fool's Champion Funds newsletter service and doesn't own any of the securities mentioned. The Fool has a strict disclosure policy, and you can read all about it right here.