The Immediate Effect of COVID-19 Policies on Social-Distancing Behavior in the United States

Abstract

Objective: Although anecdotal evidence indicates the effectiveness of coronavirus disease 2019 (COVID-19) social-distancing policies, their effectiveness in relation to what is driven by public awareness and voluntary actions needs to be determined. We evaluated the effectiveness of the 6 most common social-distancing policies in the United States (statewide stay-at-home orders, limited stay-at-home orders, nonessential business closures, bans on large gatherings, school closure mandates, and limits on restaurants and bars) during the early stage of the pandemic.

Methods: We applied difference-in-differences and event-study methodologies to evaluate the effect of the 6 social-distancing policies on Google-released aggregated, anonymized daily location data on movement trends over time by state for all 50 states and the District of Columbia in 6 location categories: retail and recreation, grocery stores and pharmacies, parks, transit stations, workplaces, and residences. We compared the outcome of interest in states that adopted COVID-19-related policies with states that did not adopt such policies, before and after these policies took effect during February 15-April 25, 2020.

Results: Statewide stay-at-home orders had the strongest effect on reducing out-of-home mobility and increased the time people spent at home by an estimated 2.5 percentage points (15.2%) from before to after policies took effect. Limits on restaurants and bars ranked second and resulted in an increase in presence at home by an estimated 1.4 percentage points (8.5%). The other 4 policies did not significantly reduce mobility.

Conclusion: Statewide stay-at-home orders and limits on bars and restaurants were most closely linked to reduced mobility in the early stages of the COVID-19 pandemic, whereas the potential benefits of other such policies may have already been reaped from voluntary social distancing. Further research is needed to understand how the effect of social-distancing policies changes as voluntary social distancing wanes during later stages of a pandemic.

Keywords: COVID-19; difference-in-differences; social distancing; stay-at-home.

Figure 1

Aggregate trend in presence at home relative to the start date of the first social-distancing policy implemented in each state during the coronavirus disease 2019 pandemic, using Google community mobility data, United States, February 15–April 25, 2020. The x-axis shows the number of days relative to implementation of the first social-distancing policy. The y-axis shows changes in presence at home relative to the baseline period (January 3–February 6, 2020). The vertical line indicates the day the first social-distancing policy went into effect in the state.

Figure 2

Effect of implementation of statewide stay-at-home policy on presence at home during the coronavirus disease 2019 pandemic, using Google community mobility data, United States, February 15–April 25, 2020. Gray areas highlight 95% CIs. The x-axis shows the number of days relative to implementation of the first social-distancing policy. The y-axis shows changes in presence at home relative to the baseline period (January 3–February 6, 2020). The horizontal line indicates zero estimated coefficient.

Figure 3

Effect of implementation of social-distancing policies on presence at home during the coronavirus disease 2019 pandemic, United States, February 15–April 25, 2020. Gray areas highlight 95% CIs. The x-axis shows the number of days relative to implementation of the first social-distancing policy. The y-axis shows changes in presence at home relative to the baseline period (January 3–February 6, 2020).