In Ferguson, Missouri, a community of 21,000 where the poverty rate doubled since 2000, the dynamic has bred animosity over racial segregation and economic inequality. Protests over the police killing of an unarmed black teenager on Aug. 9 have drawn international attention to the St. Louis suburb’s growing underclass. Such challenges aren’t unique to Ferguson, according to a Brookings Institution report July 31 that found the poor population growing twice as fast in U.S. suburbs as in city centers.