P.S.: > Just consider how accurate past population estimates have been. Uh, fairly accurate as far as I know? There were always bad extrapolations and naive p

P.S.: > Just consider how accurate past population estimates have been. Uh, fairly accurate as far as I know? There were always bad extrapolations and naive papers and articles, but the state of the art predictions didn't do badly, especially after data quality improved. Also, again, the major driver for the predicted dynamics is the collapse in fertility rate that has already happened, and no longer needs to be predicted. This is a vastly simpler question now than it was in the 70s. Look at this graph: https://population.un.org/wpp/Graphs/Probabilistic/FERT/TOT/935 https://population.un.org/wpp/Graphs/Probabilistic/FERT/TOT/... Of course in 1970 it's almost impossible to predict how quickly Asia will experience the cultural, economic and technological changes that reduced the fertility in Europe dramatically over the previous century. Today the transition towards small family sizes has happened. We still have drift (as we see in Europe too) but the important major driver of going from roughly 6 children per woman to 2 children per woman has happened. So the biggest uncertainty factor in old forecasts is gone.