Interdependence and the Cost of Uncoordinated Responses to COVID-19

Abstract

Social distancing is the core policy response to COVID-19. But as federal, state and local governments begin opening businesses and relaxing shelter-in-place orders worldwide, we lack quantitative evidence on how policies in one region affect mobility and social distancing in other regions and the consequences of uncoordinated regional policies adopted in the presence of such spillovers. We therefore combined daily, county-level data on shelter-in-place and business closure policies with movement data from over 27 million mobile devices, social network connections among over 220 million of Facebook users, daily temperature and precipitation data from 62,000 weather stations and county-level census data on population demographics to estimate the geographic and social network spillovers created by regional policies across the United States. Our analysis showed the contact patterns of people in a given region are significantly influenced by the policies and behaviors of people in other, sometimes distant, regions. When just one third of a state’s social and geographic peer states adopt shelter in place policies, it creates a reduction in mobility equal to the state’s own policy decisions. These spillovers are mediated by peer travel and distancing behaviors in those states. A simple analytical model calibrated with our empirical estimates demonstrated that the “loss from anarchy” in uncoordinated state policies is increasing in the number of non cooperating states and the size of social and geographic spillovers. These results suggest a substantial cost of uncoordinated government responses to COVID-19 when people, ideas, and media move across borders.

Test sensitivity is secondary to frequency and turnaround time for COVID-19 surveillance

“…Continued clarification of these within-host dynamics would increase the impact and value of this, and other [31,32,35,36] modeling studies. Finally, we modeled participation in surveillance testing regimens (or refusal thereof) as statistically independent between individuals, but health-related behaviors have been shown to be socially [37] and geographically [38,39] correlated. Clustered refusal of surveillance testing, or refusal to isolate upon testing positive, could present challenging barriers to implementation.…”

Modeling the combined effect of digital exposure notification and non-pharmaceutical interventions on the COVID-19 epidemic in Washington state

“…Looking ahead to future work, we are considering the question of coordination between different regions when deploying digital exposure notification as part of a suite of non-pharmaceutical interventions. The United States has seen a highly spatially varied response to the COVID-19 pandemic, with significant consequences to epidemic control ( 73 ) . Under the conditions of varying cross-county and cross-state flows, we seek to quantify the empirical efficiency gap between coordinated and uncoordinated deployments and policies around testing, tracing, and isolation in which a digital exposure notification system can aid.…”

College Openings in the United States Increased Mobility and COVID-19 Incidence

“…These data measure the number of devices that are detected each day in each CBG, from July 15th through Sunday September 13 th . SafeGraph data have been used in several recent publications (3)(4)(5).…”