  Segregation is a key challenge in promoting more diverse and inclusive
cities. Research based on smartphone data has revealed that segregation can
extend beyond residential areas into everyday activities like visiting shops
and restaurants. The impact of these activities on segregation, however, is
unclear. Some studies suggest that they promote mixing, while others indicate
they reinforce segregation. Here, we elucidate how day-to-day mobility shapes
overall segregation levels, looking at the distinctive segregation experienced
by native and foreign-born individuals. Our study is based on ~320,000
smartphone trajectories collected in Sweden, where immigration creates profound
divides. We find that while mobility levels generally promote mixing for
native-born individuals, foreign-born individuals remain segregated in their
out-of-home activities. Using counterfactual simulations, we show that this
heterogeneous effect of mobility on experienced segregation results mainly from
two mechanisms: homophily and limited travel, i.e., foreign-born individuals
(i) prefer destinations visited by similar individuals, and (ii) have limited
mobility ranges. We show that homophily plays a minor role, while limited
mobility, associated with reduced transport access, limits opportunities for
foreign-born to diversify their encounters. Our findings reconcile conflicting
literature and suggest that enhancing transport accessibility in foreign-born
areas could reduce social segregation.
