Paul Kedrosky has dug up this interesting map of the spread of the Black Death in Europe in the 14th century – a process that took place gradually, over a span of four years.
So how would such a map look if used to plot the spread of a pandemic today, Kedrosky wonders? Well:
there would be similarities, of course, but there would also be big differences. Instead of contiguous, banded advance you would see viruses hurled ahead of the index cases by air travel, like spot fires a mile ahead of a Santa Ana-driven wildfire. Instead of bands you would have clusters and jumps, mostly corresponding to airline disease vectors. And instead of four years to travel through a corner of the known world, you would have the virus around the world in four days, as is the case today with this H1N1 swine outbreak.
Interesting coda: in comments, Matt Dubuque notes that when the Black Death wiped out a significant chunk of the English labour force in 1340, remaining agricultural labourers were able to crank their wage rates sky high. Presto! – major resource transfer from rich to poor.
