A Global Analysis of the Effectiveness of Policy Responses to COVID-19

It took one year of collaborative efforts to develop vaccines for the SARS-Cov-2 virus at the heart of the COVID-19 pandemic. During that time, governments implemented many mitigation policies in an effort to curb the spread of the virus with varying results. In this paper, using country-level daily time series from Our World in Data, we undertake a global analysis of the propagation of the virus, policy responses to the pandemic, human mobility patterns, and inferred compliance levels. Publicly available datasets provide an opportunity to study how the virus, rules, and vaccines influenced human behaviour, highlighting the effects of high death counts and mortality ratios on people’s willingness to comply with policies and demonstrating evidence of long-term fatigue. Compliance was quantified as the correlation between the stringency of government policies and willingness to stay at home. Compliance dropped from over 85% in the first half of 2020 to less than 40% at the start of 2021, driven by various factors including economic necessity and optimism coinciding with the rollout of vaccines. A variety of policies were implemented worldwide in response to COVID-19 ranging from facial coverings to restrictions on mobility and these are compared using an empirical assessment of their impact on the growth rate of case numbers. Our analysis makes a strong case for masks as the most cost-effective non-pharmaceutical intervention currently available. Specifically, masks were strongly correlated with declining cases, four times more impactful than school closures, and approximately double that of other mobility restrictions (workplace closures, cancellation of public events, and stay-at-home requirements). Gathering restrictions were the second most effective, delivering declines over two weeks versus the one-month timescale for masks. International Travel Controls and Public Information Campaigns had negligible effects. We also assess how socioeconomic factors explain compliance with “lockdown-style” policies and establish that literacy rates and income support played key roles in maintaining compliance and enabling citizens to cope during the pandemic. A 10% increase in a country’s literacy rate was associated with a 3.2% increase in compliance, while income support of greater than half of previous earnings was found to deliver up to 4.76% more compliance.