"The question for historians, sociologists, and demographers is whether replacement level fertility is compatible with modern values of individuality, choice, and control, and if so, how." I hope more academics will take up this question, rather than assuming the answer must be "no."

"Even if fertility rates drop as fast as projected, the top of the population spike will be in about 2080. We will only get back down to our current population in about 2150. One way or another, we need accelerated, human-created solutions to climate change."

www.briefingbook.info/p/the-econom...

Hannah: "After the Spike … explores all of these population issues in more detail. As is quite rare for a book looking at birth choices and reproductive decisions, it’s compassionate rather than preachy or pushy… a very good anchor to inform and open up these conversations."

We discuss climate impacts and much more in After the Spike: Population, Progress, and the Case for People. afterthespike.com

Hannah’s substack: www.sustainabilitybynumbers.com/p/population...

Another is we’re looking, in part, at India—which ends up being meaningfully different.

One difference is that Phil and Melissa are looking, in part, at cohort fertility at ages when women haven’t yet completed their fertility. They are previewing a likely future of completed fertility. We’re restricting to cohort parity at age 40. So the past.

Thanks Jacob. Gift link: www.nytimes.com/2025/06/29/o...

Thanks Kyle!