I think the whole thing is a load of nonsense. There are lots of things that are likely to impact fertility rates.
Firstly, it doesn’t at all account for people trying to do something, like generous child tax credits or similar. It requires large numbers of humans to see that the population has declined for centuries, and do nothing to fix this.
Then there is the more high tech stuff, artificial wombs and robot childcare, life extention anti aging tech, or a full tech singularity.
Then there are random economic shifts. A rise in remote work sees many people leaving cities, they move to large countryside houses with room for many children. (And the ability to look after kids while working)
Then there is evolution, biological and cultural.
Then the economic conditions that created the fall in fertility require a level of tech and wealth. What is the proposed model of the economy doing here. If we are reverting to medieval serfdom, fertility will rise. If we are looking at a high tech and wealthy society, why have they not invented any of the techs that would change the game? Is biological immortality really that hard? And more to the point, what disaster would kill 500 million wealthy, high tech people spread across the world that wouldn’t also kill 8 billion people?
I am really struggling to imagine any model of the future that fits their graph. As far as I can tell, their model was constructed by looking at some fertility data, and then pretending that, apart from the changes in fertility and population, nothing else would ever happen.
I think the whole thing is a load of nonsense. There are lots of things that are likely to impact fertility rates.
Firstly, it doesn’t at all account for people trying to do something, like generous child tax credits or similar. It requires large numbers of humans to see that the population has declined for centuries, and do nothing to fix this.
Then there is the more high tech stuff, artificial wombs and robot childcare, life extention anti aging tech, or a full tech singularity.
Then there are random economic shifts. A rise in remote work sees many people leaving cities, they move to large countryside houses with room for many children. (And the ability to look after kids while working)
Then there is evolution, biological and cultural.
Then the economic conditions that created the fall in fertility require a level of tech and wealth. What is the proposed model of the economy doing here. If we are reverting to medieval serfdom, fertility will rise. If we are looking at a high tech and wealthy society, why have they not invented any of the techs that would change the game? Is biological immortality really that hard? And more to the point, what disaster would kill 500 million wealthy, high tech people spread across the world that wouldn’t also kill 8 billion people?
I am really struggling to imagine any model of the future that fits their graph. As far as I can tell, their model was constructed by looking at some fertility data, and then pretending that, apart from the changes in fertility and population, nothing else would ever happen.