[kubanczyk]

Just for the sake of fun and clashing some worldviews, I am quite concerned that the population size will be shrinking.

As soon as some nation makes contraceptives economically available, the native population growth goes negative. Do you know many families with three children? Because that seems like a minimal number, no?

Immigrants who (1) come when younger, and further (2) have more children mask this problem a bit, but their supply is limited. (Sorry for my insensitivity, I'm not from The West myself.) The easy contraceptives will get to even poorest countries in a generation or two. There will be a Big Shrink before the narrative of fertility takes hold again.