How does a pandemic affect an economy? Obviously, it’s a multilayered topic and FRED has limits to what it can reveal. The good news, of course, is that large-scale pandemics are rare. So the economic effects for most of these outbreaks are hard to see by graphing data. But we can take two of the most extreme examples, which will have visible effects in the data: the Black Death of the mid 14th century and the Spanish flu of 1918-1920.