The Daily Ballet of Temporary Integration: Spatio-Temporal Segregation Dynamics in Metropolitan U.S.A.

Elijah Knaap, Sergio Rey, Renan Xavier Cortes, Wei Kang

“A recent wave of scholarship examines the ways that daily activity spaces contribute to the experience of racial and ethnic segregation in large cities. In this paper, we take a different approach, leveraging administrative data on the residential and workplace locations of employees in large American metropolitan regions to examine daily and annual fluctuation in multiscalar segregation. In each MSA we measure racial and ethnic segregation in local residential and workplace “egohoods”, defined as the set of census blocks accessible within a 25 minute walk along the pedestrian transportation network. We then construct multiscalar segregation profiles by increasing the travel bandwidth and re-computing our segregation index. Measuring the gap between residential and workplace segregation statistics at each scale reveals the extent that residential locations play in exacerbating urban segregation, and the role that daily commuting plays in overcoming these patterns to achieve temporary integration. Repeating this process for each year between 2010 and 2017, we quantify the variance in segregation levels over time for each location and at each spatial scale. Our results show that during work hours, the vast majority of cities are highly racially integrated at all spatial scales, thanks to the cosmopolitan nature of urban labor markets, but daily transport patterns and persistent residential segregation work to overcome this temporary state of togetherness, leaving most neighborhoods deeply segregated at night and on the weekends, particularly at smaller spatial scales. We interpret these findings in light of recent COVID-related trends that include increased teleworking and a return to suburbanization.”