The economic expansion of the 1990s brought wage increases and low unemployment, diluting poverty and cutting the number of people living in high-poverty neighborhoods by about 25 percent. Many policy experts believed at the time that the era of urban decay was coming to an end. But as Mr. Jargowsky observes, that’s not how things worked out. In a new analysis of census data, he finds that the number of people living in high-poverty slums, where 40 percent or more of the residents live below the poverty level, has nearly doubled since 2000.
Meanwhile, he writes, poverty has become more concentrated: More than one in four of the black poor, nearly one in six of the Hispanic poor and one in 13 of the white poor now live in a neighborhood of extreme poverty. Impoverished families are thus doubly disadvantaged — by poverty itself and by life in areas ravaged by the social problems that flow from it.