There's nothing stopping high birth rates in areas where quality of life is low - it just has to be balanced by high death rates. Suppose there's a country wher

There's nothing stopping high birth rates in areas where quality of life is low - it just has to be balanced by high death rates. Suppose there's a country where it's possible to feed a million people, and there are already a million people. There is no economic growth. Suppose about a quarter of the population is women of childbearing age, and they each have a baby every five years, so each year there are 50,000 new people. That's perfectly sustainable as long as 50,000 of people die each year. That's 1/20 of the population dying each year, so that implies high death rates and short lifespans. It would suck, but it would be sustainable. And that's pretty much how the world was for most of history.