By Derek Thompson

Baltimore did not need more negative publicity this week. But in a bit of fateful timing, the Equality of Opportunity Project of Harvard University has released two papers concluding that the income mobility for poor children in Baltimore City is worse than in any large county in America. Every year spent in Baltimore “reduces a child’s earnings by 0.7 percent per year, generating a total earnings penalty of approximately 14 percent for children who grow up there from birth,” Raj Chetty and Nathaniel Hendren write.

Geography is not quite destiny. But neighborhoods can dramatically shape the economic prospects of those who grow up there. One hour south on the I-95 of Baltimore is Fairfax, Virginia, one of the 10 best large counties for low-income children. Growing up in Fairfax for 18 years raises a typical low-income child’s household earnings by 11 percent by the time he’s in early adulthood. All else equal, the difference between growing up in Fairfax rather than Baltimore, these studies say, amounts to hundreds of thousands of dollars of lifetime earnings.

The two new studies, beautifully summarized in a portfolio of articles in the The New York Times, arrive at one unmistakable conclusion: Some cities and neighborhoods keep their residents stuck in vicious cycles of poverty while others have a proven track record of turning poorer children into economic success stories. One study looked at low-income families who took vouchers from the government in a randomized 1990s study, which moved thousands of families from housing projects to counties with less poverty. A new analysis of the experiment shows that “every year spent in a better area during childhood increases a child’s earnings in adulthood.”

In other words, the value of moving to a county with high upward mobility is not just a matter of where, but also when: The earlier the move, the better the outcome.

Read More The Curse of Segregation – The Atlantic.