Dependency ratios are already causing difficulties in health, social care, pensions and labour force - those will be turbo-charged. More 'left behind' areas. Potential (at 80% drop over 2 gens) to enter a vicious cycle of high tax, low innovation, increasing decline.
I'm sceptical that eg cheaper houses will cause societies to 'pull out of it' when population drops, if having 0 or 1 child has become the norm. And in democracies, the response may be to shaft the young even more as their relative voting power declines (certainly what has happened in UK).
I agree extinction is unlikely, due to Amish if nothing else. But long term societal upheaval and negative consequence seems larger than anything other than climate change. And unlike the latter, where there's a lot of effort, it's one that is largely ignored.
I think it’s because climate change is tending towards BAD whereas the fertility one is just tending towards DIFFERENT. It’s more like AI than climate change.
See, this makes me think our economic models are wrong, rather than the fertility rate.
But it’s economy in the very widest sense - as in, within human societies, healthy middle-age-range adults are required to care for both the old and the young. If the adults-to-old ratio is very unbalanced that’s not great. And adults only come from babies.
(I am also very unbothered about rates of 1.7 ish - a slow decline feels manageable and possibly a good thing. But 100 old people -> 15-20 new people feels very unstable.)