The so-called Demographic Transition Theory, has been accepted as a matter of faith by warm-hearted, if not, bleeding heart liberals. Give massive quantities of foreign aid to countries like Africa, and their population growth rate will approximate that of the West:
https://en.wikipedia.org/wiki/Demographic_transition
Economic development causes a fertility decline. But, applied to the West, the “theory” ignores a range of other variables which are probably more important, such as feminism, women’s liberation ideology, and general cultural decadence produced by the creation of a consumer society. Correlation does not prove causality. The “theory” seems to be refuted by the case of Africa, where despite masses of foreign aid, and so-called “development,” fertility rates continue to climb, so that over one third of all people on Earth will be African by 2100:
https://qz.com/1099546/population-growth-africans-will-be-a-third-of-all-people-on-earth-by-2100/
https://qz.com/1016790/more-than-half-of-the-worlds-population-growth-will-be-in-africa-by-2050/
