Super interesting data points! Just thinking about the world population being 250-400million in AD1000 is a huge change to most people's mental models.<p>However, the basic premise of the article is a bit in question - that GRRM/readers indicate that the world itself is realistic - SOCIAL realism is the more abject term here. Lots of numbers are thrown about in the books - even on a relativistic scale these are (as the post stated) incredibly improbable. But its not particularly important to the enjoyment of the story or the "realism" that people claim to attach to.