The increase in gross domestic product, the broadest measure of the economy's performance, in the July-September quarter was more than double the 3.3 percent rate registered in the second quarter, the Commerce Department reported Thursday.
The 7.2 percent pace marked the best showing since the first quarter of 1984. It exceeded analysts' forecasts for a 6 percent growth rate for third-quarter GDP, which measures the value of all goods and services produced within the United States.
"Inventories managed to plunge in the quarter. The decline in inventories is twice as large as the second quarter," CitiGroup senior economist Steven Whiting told CBS Radio News. "This leaves us optimistic that growth will remain strong over the next few quarters."
The economy's recovery from the 2001 recession has resembled the side of a jagged cliff; a quarter of strength often has been followed by a quarter of weakness. But analysts are saying that pattern could be broken, considering increasing signs the economy finally has shaken its lethargy and is perking up.
"The economy is just shaking off a weak period here, and if we can keep demand growing at a good rate, we should see signs of employment improving," said Whiting.
Near rock-bottom short-term interest rates, along with President Bush's third round of tax cuts, have helped the economy shift into a higher gear during the summer, economists say.
"The growth rate is a testament to the power of monetary and fiscal stimulus to boost final demand," said CBS MarketWatch Washington Bureau Chief Rex Nutting. "John Maynard Keynes would be proud of his disciples, Alan Greenspan and George W. Bush."
The next challenge is making sure the rebound is self-sustaining, the economists say.
To sustain the recovery, economists told CBS News Correspondent Anthony Mason, the economy will have to create jobs. With demand up, they predict, companies will have to produce more, and that means hiring more workers.
"But that's hope. It's faith. It's not showing up yet. And that is the one wild card that could derail this recovery," says Bill Cheney, chief economist for John Hancock.
Democrats argued that the tax cuts contributed to a record budget deficit in the recently ended 2003 fiscal year and have done little to spur significant job growth.
Although the nation's payrolls grew by 57,000 in September — the first increase in eight months — the economy needs to add a lot more jobs than that each month to drive down the 6.1 percent unemployment rate, analysts have said.
"Going forward it's going to be very hard to do that," Whiting said.
The administration has argued that as economic growth improves, meaningful job creation will follow. Bush will be counting on that as he heads into the 2004 presidential election season.
Amid signs that the recovery is regaining traction, the Federal Reserve on Tuesday decided to hold a key short-term interest rate at a 45-year low of 1 percent. Super-low short-term rates may give consumers and businesses an incentive to spend and invest more, boosting economic growth.
Economists believe the economy will grow at a slower — but still healthy — 4 percent rate in the final quarter.
In the third quarter, consumers ratcheted up their spending at a brisk 6.6 percent annual rate. That was the biggest increase since the first quarter of 1988 and was up from a 3.8 percent pace in the second quarter.
Consumers in the third quarter spent lavishly on big-ticket items, such as cars, boosting such spending by a whopping 26.9 percent rate. And, they also spent briskly on "nondurables" such as food and clothes, which grew at a 7.9 percent pace, the strongest showing since the first quarter of 1976.
While consumers have been the main force keeping the economy going, there are more signs that businesses are starting to do their part.
Especially encouraging was the 15.4 percent growth rate in spending by businesses on equipment and software in the third quarter. That marked the largest increase since the first quarter of 2000 and was up from a 8.3 percent growth rate in the second quarter.
Sustained turnarounds in capital spending and in hiring are crucial to the economy's return to full throttle. Economists said business wants profits to improve and wants to be sure of the recovery's vigor before it goes on a spending and hiring spree.
The red-hot housing market, powered by low mortgage rates, also contributed to the strong showing on third quarter GDP. Investment on residential projects grew at a 20.4 percent rate, the biggest increase since the second quarter of 1996, and more than three times the 6.6 percent growth rate seen in the second quarter.
Federal government spending, which grew at a 1.4 percent rate, was only a minor contributor to GDP in the third quarter. Spending on national defense was flat. But in the second quarter, military spending on the Iraq war — which grew at a whopping 45.8 percent rate — helped to catapult economic growth.
A better trade picture in the third quarter also contributed to GDP growth.
But inventory reduction by businesses continued to be a drag on the economy and reduced third-quarter GDP by 0.67 percentage point. And a continuing reluctance by businesses to build up stocks suggest that executives remain wary of the rebound's staying power.