Revealing exacerbated socioeconomic stratification of urban mobility: A case study in Beijing, China

As the COVID-19 pandemic recedes, urban life, economic activities, and transportation systems appear to have returned to normal. Yet latent post-pandemic impacts on shifts in socioeconomic stratification within human mobility remain under-explored. Using large-scale longitudinal mobile signaling data for nearly 8 million residents in Beijing between 2019 and 2024, weighted using census data and integrated with social attributes and housing price data, this study examines how socioeconomic stratification patterns and mobility behaviors evolve across socioeconomic groups. Here, we show that the potential stratification has intensified in the post-pandemic era. First, the place-level and inter-group contact-based socioeconomic stratification index increased by 34.83% and 32.34%, respectively. Counterfactual simulations reveal that shortened travel distances and homogeneous mobility preferences reduced opportunities for cross-group encounters. Second, residential proximity and shared social attributes significantly explain variations in opportunities for inter-group co-presence. Spatial disparities in urban infrastructure configuration can either mitigate or reinforce mobility-related socioeconomic stratification across locations. Collectively, this study underscores that spatial context, socioeconomic characteristics, and behavioral preferences shape mobility stratification, offering empirical evidence for understanding post-pandemic socioeconomic stratification dynamics.