Washington ? The economy in the third quarter galloped ahead faster than an initial estimate, which was already the swiftest in nearly two decades. That burst, along with a surge in consumer confidence, raised hopes for the recovery’s staying power.

The broadest measure of the economy’s performance, gross domestic product, increased at a 8.2 percent annual rate in the July-to-September quarter, even better than the 7.2 percent rate estimated a month ago, the Commerce Department said Tuesday.

The new GDP reading — embraced by President Bush as proof of the effectiveness of his administration’s economic policies — represents the strongest growth since the first quarter of 1984, when the economy surged at a 9 percent pace. The new estimate is more than double the 3.3 percent rate in the second quarter.

“I think the economy is back,” declared an optimistic Mark Zandi, chief economist at Economy.com. “It has evolved from a very fragile recovery to a sustainable rebound.”

In other economic news, consumers’ confidence in the economy climbed in November to the highest level in more than a year as people perceived the job market to be turning around, the Conference Board reported. The private research group’s consumer confidence index rose to 91.7 in November, up from a revised 81.7 in October.

“The surge in consumer confidence couldn’t come at a better time,” said Joel Naroff, president of Naroff Economic Advisors. “Households are becoming more confident about the labor markets and the future in general and that bodes well for this crucial holiday shopping season.”

Some analysts believe the economy is growing at a slower but still healthy rate of about 4 percent in the current October-to-December period, as some of the stimulus that helped in the third quarter — tax cuts and a wave of mortgage refinancing — fades.