[dariusj18]

So the source for that appears to be http://www.ggdc.net/maddison/oriindex.htm "Statistics on World Population, GDP and Per Capita GDP, 1-2008 AD" but I can't find the methodology used. It is definitely an interesting spreadsheet to look through.

[xyzzyz]

Maddison is garbage source for anything pre 1800s, FWIW. His all "data" before 1800s is completely made up. See http://faculty.econ.ucdavis.edu/faculty/gclark/Book_Reviews/...