Education doesn’t guarantee social mobility, writes Rachel M. Cohen in The Atlantic. “In the 21st century, the best anti-poverty program around is a world-class education,” Barack Obama declared in his 2010 State of the Union address. It ain’t necessarily so, writes Cohen. Geography plays a big role in whether a child born to low-income parents will rise to the top of the economic ladder, concluded a 2014 study led by Stanford’s Raj Chetty. The economists found that “a poor c