The term "good loss" is most commonly attached to valiant efforts by underdog sports teams, but it may just as well fit a Rust Belt region that has suffered decades of population drain.

In numbers released today, the U.S. Census Bureau estimates that the seven-county Pittsburgh metropolitan area lost 2,967 residents between July 1, 2007, and July 1, 2008. From among 363 metro areas nationally, it was one of 50 to lose population, and only Detroit, Cleveland, Flint, Mich., and Youngstown lost more people during that span.

But here's the silver lining on an ever-gray topic: The local region's estimated annual loss was by far the smallest in this decade. Every other year since 2000, the combination of Allegheny, Armstrong, Beaver, Butler, Fayette, Washington and Westmoreland counties lost twice as many residents as in 2007-08, including a plummet of more than 15,000 residents in 2004-05.

Allegheny County was entirely responsible for the region's population drop last year. Allegheny showed a net loss of 3,326 residents, according to the census estimates, which are based on births, deaths, addresses on Internal Revenue Service tax filings, and other data. That means the other six counties had a net gain of 359, largely as a result of migration into Butler and Washington counties.

But even Allegheny County officials could be pleased by shrinkage that was about one-third the rate of what previously occurred in the decade. It remains the 30th largest county in the country, with 1,215,103 residents, while the metropolitan area is still 22nd biggest, with 2,351,192 people.

"It is good news that the population decline has slowed down," said county spokesman Kevin Evanto. "The turnaround has to start somewhere ... and it's better to have this conversation rather than one about population decline expanding exponentially."

Analysts of the local improvement point primarily to the strength of Western Pennsylvania's economy, which has consistently had an unemployment rate below the national average. Other areas that might have ordinarily drawn transplants from Pittsburgh have suffered worse in the recession, slowing the out-migration that has headed the region's population story for the past half-century.

Chris Briem, a regional economist at the University of Pittsburgh who studies population trends, said such fluctuations in economic migration represent the biggest local variable. More deaths than births occur in the region every year because of its relatively old population, and that is not forecast to change soon.

Considering the Pittsburgh economy's relative strength, Mr. Briem said he would not be surprised if the population figures released a year from now look even better for the region.

"It can take some time if you lose your job, a year or two or more, to make a big decision to move," he said. "July 1, 2008, might be just the beginning of where we see the impact of these migration decisions on the local population."

The Southwestern Pennsylvania Commission, a planning agency for nine counties, actually forecasts that they will gain 468,161 people in the span between 2005 and 2035. Such long-term predictions can be dicey, but Executive Director James Hassinger expressed confidence that the regional population will bottom out by 2015 and slowly tick upward afterward.

"This is part of that period where things are shifting," considering the new numbers, he said.

The mirror image of the local trend is a slowdown in what had been meteoric population gains in some parts of the South and Southwest. Las Vegas, for example, experienced its smallest population gain in nearly 20 years. The housing market's collapse has many people stuck in place, unable to sell and buy homes across the country.

"It's the bursting of a 'migration bubble,'" said William H. Frey, a demographer at the Brookings Institution. "Places that popped up in migration growth in the superheated housing markets earlier in the decade are now just as quickly losing their steam."

The nation's fastest-growing metro areas were Raleigh, N.C., and Austin, Texas, both home to major college campuses and high-tech industries.

The local counties' estimated July 1 populations, with their net annual gain or loss, were: Allegheny, 1,215,103 (-3,326); Armstrong, 68,790 (-214); Beaver, 172,476 (-547); Butler 182,902, (+1,168); Fayette, 143,925 (-451); Washington, 206,407 (+975); Westmoreland, 361,589 (-572).

For more details on population changes of counties and metropolitan areas, visit www.census.gov.