&gt; but that even in a hypothetical future where overpopulation is not a problem it must continue to drop.<p>This supposes that population is currently dropping because of overpopulation. I see no evidence of that. China is your best candidate as a counterexample, and it falls flat.<p>They&#x27;ve rescinded the one child policy. If you are right, fertility should climb there... but the initial indications are that a people trained to be low-fertility continue to be low-fertility even after the training stops.<p>I&#x27;m not exactly shocked.