Economic mobility — the ability of a poor kid to rise out of poverty — is lower in metro Atlanta than in any other major metropolitan area in the country. If you can’t say that metro Atlanta is where the American Dream comes to die, you also can’t claim that the dream is alive and well here.

On average, just four of 100 children born into the lowest-earning 20 percent of metro households are able to fight their way into the top earning 20 percent. Even more damning, 45 of the country’s 100 largest metro areas have mobility rates at least twice as high as that of metro Atlanta. (The study uses millions of anonymous tax returns to track unnamed individuals from childhood well into their earning years.)

And since this is going to come up anyway, let’s confront it: Our low ranking is not simply a function of race. The analysis found that low-income white children from metro Atlanta also have a hard time making their way into top-earning households. Nor do metro Atlanta’s economic struggles explain much. According to the study’s authors, “the vast majority of the difference in mobility across areas is unrelated to economic growth.”

So what does matter? School quality appears to matter. Areas with a higher concentration of two-parent families and church attendance tend to do better. And economic segregation and geographic mobility matter. Economic mobility is low in areas in which low-income people are trapped in traffic without an efficient transit system. Put simply, they lack the means to break out of their communities to compete for better-paying jobs.

And here’s where stereotypes once again become a problem.

Metro Atlanta has not been able to address its crippling transportation problems, nor has it been willing to embrace transit. In part that’s because of a perception that transit is an inner-city amenity that suburban areas do not need and should not have to subsidize.

Yet Atlanta suburbs need transit far more than the inner city, which already boasts low commuting times.

I understand that claim will be controversial, but look at the data. According to a recent book, “Confronting Suburban Poverty in America,” metro Atlanta ranked fourth in the country in the growth of suburban poverty from 2000 to 2010. Today, 87 percent of the region’s poor live in the suburbs. Seventy-nine percent of those who rely on housing vouchers live in the suburbs.

Look also at the demographic data: Between 2000 and 2010, the black population within the city of Atlanta fell by 11.26 percent, while the white population rose by 16.45 percent. From 2010 to 2012, the city’s population grew by 5.6 percent, a faster growth rate than Gwinnett County and twice the rate of Cobb. Most of that’s an influx of young, college-educated people to Atlanta, which now has a higher percentage of college-educated people than Cobb.

And who’s moving to Cobb, Gwinnett and other suburban areas? Between 2000 and 2010, the black population of Cobb grew by 50 percent, its Hispanic population grew by almost 80 percent and its white population fell by 2.72 percent. In Gwinnett, the black population grew by 146.5 percent, and the Hispanic population by 152.6 percent.

We are creating a region in which poor and minority families — drawn to suburban areas by cheaper housing — are becoming trapped there without transit in a form of economic segregation, while the inner city gentrifies and prospers. We can see it happening, yet do nothing.