The COVID-19 pandemic has disrupted Americans’ daily mobility, which could contribute to greater social stratification. Relying on SafeGraph cell phone movement data from 2019 and 2020, we use two indices proposed by Phillips and colleagues (2019) to measure mobility inequality between census tracts in the 25 largest U.S. cities. These measures capture the importance of hubs and neighborhood isolation in a network. In the earliest phases of the pandemic, neighborhood isolation rapidly increased, and the importance of downtown central business districts declined. Mobility hubs generally regained their importance, whereas neighborhood isolation remained elevated and increased again during the latter half of 2020. Linear regression models with city and week fixed effects find that new COVID-19 cases are positively associated with neighborhood isolation changes a week later. Additionally, places with larger populations, more public transportation use, and greater racial and ethnic segregation had larger increases in neighborhood isolation during 2020.

中文翻译：

---

COVID-19 大流行期间的社区隔离

COVID-19 大流行扰乱了美国人的日常活动，这可能会导致更大的社会分层。依靠 2019 年和 2020 年的 SafeGraph 手机移动数据，我们使用 Phillips 及其同事（2019 年）提出的两个指数来衡量美国 25 个最大城市人口普查区之间的流动性不平等。这些措施体现了网络中集线器和社区隔离的重要性。在大流行的最初阶段，社区隔离迅速增加，市中心中央商务区的重要性下降。移动枢纽总体上重新发挥了重要作用，而社区隔离在 2020 年下半年仍然升高并再次增加。具有城市和周固定效应的线性回归模型发现，新的 COVID-19 病例与一周后的社区隔离变化呈正相关。此外，在 2020 年，人口较多、公共交通使用较多以及种族和民族隔离程度较高的地方，社区隔离的增加幅度较大。