The Coronavirus and the Great Influenza Epidemic - Lessons from the 'Spanish Flu' for the Coronavirus's Potential Effects on Mortality and Economic Activity. Robert Barro, 2020, Paper, "Mortality and economic contraction during the 1918-1920 Great Influenza Epidemic provide plausible upper bounds for outcomes under the coronavirus (COVID-19). Data for 43 countries imply flu-related deaths in 1918-1920 of 39 million, 2.0 percent of world population, implying 150 million deaths when applied to current population. Regressions with annual information on flu deaths 1918-1920 and war deaths during WWI imply flu-generated economic declines for GDP and consumption in the typical country of 6 and 8 percent, respectively. There is also some evidence that higher flu death rates decreased realized real returns on stocks and, especially, on short-term government bills." Link