While a large literature has documented substantial variation in social inequality based on levels of differentiation within secondary school systems, key mechanisms are largely untested. We explore the link between social inequality and intergenerationally mobility in U.S. high schools. We describe patterns in intergenerational mobility in education and in social network composition across high schools in the U.S., using a sample of adolescents from the Add Health study. For each of the roughly 130 middle/high schools in our sample, we estimate intergenerational persistence coefficients: these describe the dependence of a child educational attainment on their parent's educational attainment. Using information on self-nominated friends of each sampled student, we also calculate measures of friend network segregation by mother's education: these indicate the degree to which the distribution of parental education differs between individual friend networks and the overall school population. We then estimate the impact of SES-based stratification of friendship networks on intergenerational mobility. We find that socially segregated schools are associated with lower intergenerational mobility. Precise measures of social segregation within the school show a greater impact on mobility than measures of spatial segregation in the county where the school is located. Schools may be able to affect intergenerational mobility through influencing the social networks that form among their students.

虽然大量文献记录了基于中学系统内部分化程度的社会不平等的巨大变化，但关键机制在很大程度上未经检验。我们探讨了美国高中的社会不平等与代际流动之间的联系。我们使用 Add Health 研究中的青少年样本描述了美国高中教育和社交网络构成的代际流动模式。对于我们样本中大约 130 所中学/高中中的每一所，我们估计了代际持续系数：这些系数描述了儿童教育程度对其父母教育程度的依赖性。使用每个抽样学生的自荐朋友信息，我们还计算了母亲教育程度的朋友网络隔离措施：这些表明了父母教育分布在个人朋友网络和整个学校人口之间的差异程度。然后，我们估计了基于 SES 的友谊网络分层对代际流动的影响。我们发现社会隔离的学校与较低的代际流动性有关。与学校所在县的空间隔离措施相比，学校内社会隔离的精确措施对流动性的影响更大。学校可以通过影响学生之间形成的社交网络来影响代际流动。然后，我们估计了基于 SES 的友谊网络分层对代际流动的影响。我们发现社会隔离的学校与较低的代际流动性有关。与学校所在县的空间隔离措施相比，学校内社会隔离的精确措施对流动性的影响更大。学校可以通过影响学生之间形成的社交网络来影响代际流动。然后，我们估计了基于 SES 的友谊网络分层对代际流动的影响。我们发现社会隔离的学校与较低的代际流动性有关。与学校所在县的空间隔离措施相比，学校内社会隔离的精确措施对流动性的影响更大。学校可以通过影响学生之间形成的社交网络来影响代际流动。