COVID-19 International Evidence: Some Notable Puzzles

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This article uses international evidence to argue that we still have limited knowledge about the efficacy of widely used preventive actions, such as social distancing and face masks, in containing the spread of the novel COVID-19 virus. I document three puzzles. One, Peru enacted unprecedented lockdowns early in the pandemic, which led to a record contraction in economic activity. The country’s residents also adopted near-universal face mask usage. None of these actions, however, prevented Peru from experiencing the world’s highest per capita mortality rate from the virus. Second, southeast Asian countries practically did not register cases despite being closely interconnected to the source of the virus and adopting rather lax viruscontainment policies. Third, sub-Saharan African countries were largely spared from the virus, despite being considered very high-risk countries at the onset of the pandemic. I also discuss some emerging hypotheses that could explain these puzzles. Rather than rebuffing proven preventive actions like social distancing and face mask usage, this article highlights the limited knowledge we still have on this novel disease.

Key findings:

  • Considerable evidence shows that masks and social distancing reduce the spread of COVID-19, but my review of international evidence indicates other factors may be important as well. In this article, I highlight some puzzles observed in the international data.
  • Peru enacted very strict lockdowns and near-universal face mask usage early in the pandemic, but it could not avoid record deaths.
  • Many countries in southeast Asia recorded practically no COVID-19 cases, despite their proximity to the virus source and limited social distancing. Sub-Saharan Africa did remarkably well in containing the disease despite grim projections at the onset of the pandemic.

Center affiliation: Center for Quantitative Economic Research and the Americas Center

JEL classification: E19, I19

Key words: COVID-19

The Federal Reserve Bank of Atlanta's Policy Hub The author thanks R. Anton Braun, Nikolay Gospodinov, John Robertson, Yongs Shin, and Tom Heintjes for very helpful comments. The views expressed here are the author’s and not necessarily those of the Federal Reserve Bank of Atlanta or the Federal Reserve System. Any remaining errors are the author’s responsibility. Sign up for email updates at