> This is a contentious claim, as there are different measures of “enough kids”.
I don’t agree with the comment you’re replying to, but I should add that while there are different measures, the range is extremely narrow. Most western countries are at fertility levels where without immigration they will cease to exist entirely in relatively short order.
... for values of "cease to exist entirely" measured in "populated by millions of people, but considerably fewer millions than before" and values of "relatively short order" measured in centuries.
I don’t agree with the comment you’re replying to, but I should add that while there are different measures, the range is extremely narrow. Most western countries are at fertility levels where without immigration they will cease to exist entirely in relatively short order.