During the time period Stone studied, he wrote that more than 4,200 African-Americans per year moved from Cobb, Fulton, DeKalb and Gwinnett counties to southern suburban areas, such as Henry County. More specifically, "200 black [people] a year, on net, migrated out of DeKalb County to other Atlanta counties, while almost 2,000 white [people] moved in." And in Gwinnett County, "about 2,300 black [people] moved in per year, while about 1,200 white [people] moved out."
It's this additional distinction that Stone, who is in the middle of an ongoing series on national migration, highlights: "Migration within Greater Atlanta has a measurable and significant racial bias. ... About 10 [percent] of the migration in Atlanta involves some kind of racially-biased relocation."
Annually, this net totals about 18,000 people.
"ACS estimates are an annual average taken over five years. They are a sample, and so have a margin of error," Stone said. "For county-level estimates, especially rural counties, that error can be large. Generally, the larger the sample of counties, the more confident I can be that I'm providing correct results.
"So in one-county samples like the ['core'] Atlanta counties. I'll readily admit there may be some degree of sample bias. However, there is no more accurate data, to my knowledge."
Stone wrote that his analysis about migration and how that migration splits among people of different races is meant as a converstation starter -- not the final word.
"Migration within Atlanta is impacted by numerous factors, from transportation access to cost of living to education. But race is also a major factor, and one concerning which any Southern city must, for historical reasons, take extraordinary care," Stone wrote. "Is Atlanta doing a good job measuring up to that task? That’s up to residents to say: hopefully the data I’ve presented here can be useful for informing that discussion."