Forsyth County's reputation as one of the most affluent commuter communities in the state was affirmed yet again this week, with new census data ranking the county 19th in the nation in median income.

The median household income for a family of four in Forsyth County is $72,945, second in Georgia only to similarly suburban Fayette County at $74,320.

The median income is the midpoint at which half the incomes are below it and half are above it. Georgia's median household income stands at $43,000, about the same as the median income for the country.

For University of Georgia demographer Doug Bachtel, the latest numbers -- based on 2003 data -- are not surprising.

"(Forsyth and Fayette) are suburban counties in the second-fastest growing metropolitan area in the United States," Bachtel said.

Only Los Angeles is growing faster than Atlanta.

Forsyth County's population grew 123 percent between 1990 and 2000, and most of the population growth was from newcomers. Net migration, as opposed to births within the county, accounted for 85 percent of the county's growth between 1990 and 2000.

And most of those newcomers came with college degrees and high salaries in the metro Atlanta area, looking for a community with good schools and low crime, Bachtel said.

"There are affluent people choosing to move there because of the quality of life," he said.

And as the upscale subdivisions and mini-mansions continue to sprout up around Forsyth, they keep coming.

"That affluent growth attracts more affluent growth," Bachtel said.

The housing options in Forsyth tend to exclude those who aren't well-heeled enough to keep up with the prices, Bachtel said.

The median value of an existing home in Forsyth County is now about $250,000, up from $184,600 just five years ago.

"The housing costs just keep going up and up," Bachtel said, noting rental options are few.

"It's a self-fulfilling prophesy -- you've gotta have a pretty thick wallet to live there in the first place."

Forsyth and Fayette, the bedroom community southwest of Atlanta which includes Peachtree City, both have proven to be among the most attractive places to live for the well-paid white-coller workers who have flocked to Atlanta in the past 30 years, Bachtel said. And the metro area's growth has only begun to dramatically affect outlying counties in recent decades, he said.

"Of all the demographic variables in the world, one of the things that causes the most change is urbanization," Bachtel said.

"As the growth in Atlanta spread out, the increased income and educational attainment came with it," he said. "Basically when people come to Atlanta for job opportunities, they seek out places to live for the quality of life, and they bring their income, their education, the three cars, kids and the dogs."