It's a bit strange that the author doesn't mention the population projections published in The Lancet a few years ago (https://www.thelancet.com/infographics-do

It's a bit strange that the author doesn't mention the population projections published in The Lancet a few years ago (https://www.thelancet.com/infographics-do/population-forecast https://www.thelancet.com/infographics-do/population-forecas...). They note a lot of the problems with the UN projections, which include the modeling but also include other factors, like the effect of female education. In the few years since their study came out, their numbers appear to be more accurate than the UN approach of assuming fertility ends up at 1.69 everywhere.