Impacts of social distancing policies on mobility and COVID-19 case growth in the US

Gregory A Wellenius,Thomas C Tsai,Katherine Chou,Brian Williams,Catherine Bendebury,Valeria Espinosa,Krishna Gadepalli,Tomer Shekel,Christopher Pluntke,Adam Pearce,Chaitanya Kamath,Damien Desfontaines,Arran Schlosberg,Andrew M Dai ,Ashish K Jha,Jonathan Hennessy,Alex Fabrikant,Andrew Oplinger,Swapnil Vispute,Benjamin Jacobson ,Bryant Gipson,Chinmoy Mandayam,Andrew Widdowson,Shailesh Bavadekar,Zan Armstrong,Charlotte Stanton,Royce Wilson,Adam Boulanger,Evgeniy Gabrilovich

doi:10.1038/s41467-021-23404-5

Abstract

Social distancing remains an important strategy to combat the COVID-19 pandemic in the United States. However, the impacts of specific state-level policies on mobility and subsequent COVID-19 case trajectories have not been completely quantified. Using anonymized and aggregated mobility data from opted-in Google users, we found that state-level emergency declarations resulted in a 9.9% reduction in time spent away from places of residence. Implementation of one or more social distancing policies resulted in an additional 24.5% reduction in mobility the following week, and subsequent shelter-in-place mandates yielded an additional 29.0% reduction. Decreases in mobility were associated with substantial reductions in case growth two to four weeks later. For example, a 10% reduction in mobility was associated with a 17.5% reduction in case growth two weeks later. Given the continued reliance on social distancing policies to limit the spread of COVID-19, these results may be helpful to public health officials trying to balance infection control with the economic and social consequences of these policies.

Highlights

Social distancing remains an important strategy to combat the COVID-19 pandemic in the United States
While multiple reports have examined the links between state-level social distancing policies, changes in mobility, and changes in case growth trajectories during the early phase of the pandemic[7,8,9,10,11,12,13,14,15,16,17,18], it remains unclear which state-level policies are most effective in mitigating the spread of the virus
We observed three waves of state-level responses to COVID-19: (1) a first wave occurring during the first 2 weeks of March, 2020 with state of emergency declarations, (2) a second wave during the week of March 16 where a variety of specific social distancing orders were enacted, and (3) a third wave during the last 2 weeks of March consisting of orders for residents to shelter in place (Fig. 1)

Summary

Introduction

Social distancing remains an important strategy to combat the COVID-19 pandemic in the United States. As the pandemic spread to new clusters of infection in the United States, efforts at containment and mitigation have been largely at the discretion of state and local governments, leading to a patchwork of directives to encourage social distancing These policies have included state emergency declarations, work-from-home policies, school closures, closures of non-essential businesses and services, limits placed on large social gatherings, bans on in-restaurant dining, and shelter-in-place orders[6]. We sought to: (1) quantify the effect on mobility of state emergency declarations, social distancing policies, and shelter-in-place orders, (2) identify which policies are most effective in reducing aggregate mobility, and (3) estimate the impact of changes in mobility on COVID-19 case growth in subsequent weeks. Decreases in mobility were associated with substantial reductions in case growth 2–4 weeks later

Methods

Results

Conclusion