Earnings reports from I.B.M., Google, and General Electric have shown that the world economy, particularly in Asian and emerging markets, is still churning ahead—even as the U.S. economy is slowing down.

That trend is underscored today by Caterpillar, which sells the tractors, bulldozers, and other heavy equipment used to build infrastructure in rapidly industrializing countries. Its first-quarter earnings rose 13 percent, more than expected, to $922 million, or $1.45 per share, compared with $816 million, or $1.23 per share, in the quarter a earlier.

Sales climbed 18 percent, to $11.8 billion. Sales outside North America—which now account for 58 percent of Caterpillar's business, up from 53 percent a year ago—rose 30 percent. In North America, sales were up just 4 percent.

"Even though we're currently weathering a recessionary storm in the United States, we expect the rest of the world to continue to invest in infrastructure growth well into the next decade," Jim Owens, Caterpillar's chief executive, said.

Exporters like Caterpillar have also benefited from the weak dollar, which makes their products more competitively priced abroad. Of the increase in sales this quarter, the impact of the dollar added 17 percent.

Strong global demand could generate earnings for a number of American companies that will prove stronger than current forecasts. And that could buoy stocks, notes Tom Lauricella in the Wall Street Journal.

And in a reversal from the last downturn, manufacturing may be among the few winners.

"Growth in exports...will tend to put the manufacturing sector in better stead than some other parts of the U.S. economy," Richard Fearon, Eaton's chief financial officer, told the Journal. "So this is a little bit the opposite of what happened in 2000 and 2001."