Causal impact of masks, policies, behavior on early covid-19 pandemic in the U.S.

Abstract

The paper evaluates the dynamic impact of various policies adopted by US states on the growth rates of confirmed Covid-19 cases and deaths as well as social distancing behavior measured by Google Mobility Reports, where we take into consideration people’s voluntarily behavioral response to new information of transmission risks in a causal structural model framework. Our analysis finds that both policies and information on transmission risks are important determinants of Covid-19 cases and deaths and shows that a change in policies explains a large fraction of observed changes in social distancing behavior. Our main counterfactual experiments suggest that nationally mandating face masks for employees early in the pandemic could have reduced the weekly growth rate of cases and deaths by more than 10 percentage points in late April and could have led to as much as 19 to 47 percent less deaths nationally by the end of May, which roughly translates into 19 to 47 thousand saved lives. We also find that, without stay-at-home orders, cases would have been larger by 6 to 63 percent and without business closures, cases would have been larger by 17 to 78 percent. We find considerable uncertainty over the effects of school closures due to lack of cross-sectional variation; we could not robustly rule out either large or small effects. Overall, substantial declines in growth rates are attributable to private behavioral response, but policies played an important role as well. We also carry out sensitivity analyses to find neighborhoods of the models under which the results hold robustly: the results on mask policies appear to be much more robust than the results on business closures and stay-at-home orders. Finally, we stress that our study is observational and therefore should be interpreted with great caution. From a completely agnostic point of view, our findings uncover predictive effects (association) of observed policies and behavioral changes on future health outcomes, controlling for informational and other confounding variables.

The role of mask mandates, stay at home orders and school closure in curbing the COVID-19 pandemic prior to vaccination

“…Additionally, they did not adjust for epidemics beginning at different time points in different locations or socio-demographic variables ( 14 ). The studies by Kaufman et al, Chernozhukov et al and Gallaway et al all suggest wearing masks in public locations is beneficial ( 20 , 21 , 23 ).…”

“…Moreover, an analysis of the impact of policy measures has suggested that nationally mandating face masks for employees early in the pandemic could have reduced the weekly growth rate of cases and deaths by more than 10 percentage points in late April and could have led to as much as 19 to 47 percent less deaths nationally by the end of May. Cases would have been larger by six to 63 percent without stay-at-home orders and larger by 17 to 78 percent without business closures ( 21 ). Hypothetical mask models support these results and one such study suggested that even weak (ineffective) masks could be useful in curbing disease transmission ( 22 ).…”

Zorro versus Covid-19: fighting the pandemic with face masks

“…Appropriate public hygiene and control policies would consist of mandatory mask wearing. Given the clear effect of mask wearing on infections and fatalities and the fact that a mandatory mask policy involves little economic disruption (19) and is economically attractive, we also recommend extending mandatory face mask use even for children (over 6 years of age). Attitudes regarding altruism, tolerance, and solidarity do not appear to be sufficient to achieve the necessary levels of mask wearing.…”

“…However, potential biases, especially regarding the failure to control for other non-pharmaceutical policies, have been reported. Very recently, an econometric study demonstrated the positive results of introducing masks for employees in US states in April 2020 (19). Likewise, in Germany, the introduction of mandatory mask wearing has reduced the growth rate of Covid-19 cases.…”

Public Awareness of Mask Usage in 29 Countries

“…Without vaccination and magic bullet, one of the essential items that can protect people from the disease is a face mask 1 2 . The effectiveness of wearing masks has been reported in the United States 3 , Germany 4 , Hong Kong 5 , and other regions 6 . Yet, recognition of its importance varies across nations and even within a country.…”