New evidence shows that intergenerational social mobility—the rate at which children born into poverty climb the income ladder—varies considerably across the United States. Is this current geography of opportunity something new or does it reflect a continuation of long-term trends? We answer this question by constructing data on the levels and determinants of social mobility across American regions over the 20th century. We find that the changing geography of opportunity-generating economic activity restructures the landscape of intergenerational mobility, but factors associated with specific regional structures of interpersonal and racial inequality that have “deep roots” generate persistence. This is evident in the sharp decline in social mobility in the Midwest as economic activity has shifted away from it and the consistently low levels of opportunity in the South even as economic activity has shifted toward it. We conclude that the long-term geography of social mobility can be understood through the deep roots and changing economic fortunes of places.

新的证据表明，代际社会流动性——出生在贫困中的儿童攀登收入阶梯的速度——在美国各地差异很大。当前的机遇格局是新事物还是反映了长期趋势的延续？我们通过构建 20 世纪美国各地区社会流动性水平和决定因素的数据来回答这个问题。我们发现，创造机会的经济活动的地理格局不断变化，重构了代际流动的格局，但与“根深蒂固”的人际和种族不平等的特定区域结构相关的因素却产生了持久性。中西部地区的社会流动性急剧下降，因为经济活动已从中西部地区转移，而南部地区的机会水平却持续较低，尽管经济活动已转向中西部地区，这一点就显而易见。我们的结论是，社会流动性的长期地理可以通过地方的深层根源和不断变化的经济命运来理解。