Quantifying the social distancing privilege gap: a longitudinal study of smartphone movement

Background In response to the coronavirus pandemic, social distancing became a widely deployed countermeasure in March 2020. We examined whether healthier and wealthier places more successfully implemented social distancing. Methods Mobile device location data were used to quantify declines in movement by county (n=2,633) in the United States of America, comparing April 15–17 (n=65,544,268 traces) to baseline of February 17 - March 7. Negative binomial regression was used to estimate gradients of privilege across eleven healthcare and economic indicators, adjusting for rurality and stay-at-home mandates. External validation used separate venue-specific data from Google Location Services. Findings Counties without stay-at-home orders showed a mobility decline of −52·3% (95% CI: −50·3%, −54·3%), slightly less than the decline in mandated areas (−60·8%; 95% CI: −60·0%, −61·6%). Strong linear gradients in privilege were observed. After adjusting for rurality and stay-at-home orders, counties in the highest quintile of social distancing mobility restriction had: 52% less uninsured, 47% more primary care providers, 29% more exercise space, 27% less food insecurity, 26% less child poverty, 17% higher incomes, 14% less overcrowding, 9·6% more racial segregation, 8·2% less youth, 7·4% more elderly, and 6·2% less influenza vaccination, compared to least social distancing areas. Interpretation Healthier and wealthier counties displayed a social distancing privilege gap, measured via smartphone mobility change. Structural inequities in this key countermeasure will influence immunity, and disease incidence and mortality. Funding None