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/
The ideology of the Demographic Transition, may well be condemning the West, particularly Europe to oblivion, according to other authorities:
http://www.breitbart.com/london/2018/02/08/africa-expert-warns-western-aid-contribute-migrant-crisis/
“Africa specialist Stephen Smith has warned that the next migrant crisis is on the horizon as Africa’s population continues to boom and that Western aid, particularly education, may contribute to Africans seeking a better life in Europe. Mr. Smith, the author of the new book La ruée vers l’Europe, or The Rush To Europe, warned that the exploding demographics of Africa will have direct consequences for Europe. According to Smith, in the coming decades, young Africans will likely migrate to Europe as the slowly developing economies of their home nations cannot provide them jobs, Europe1 reports. “It’s this pyramid of age that makes 40 per cent of the population less than 15 years old,” Smith said and added, “The migratory pressure can only increase.”
Smith also noted the common misconception that those who come to Europe are from poor economic backgrounds saying middle-class migrants “are the ones who come out of the water, who have a view of the world, who know where to go, who are on Facebook, who have a mobile phone and the 2,000 or 3,000 euros needed to embark on the journey.”
The West has been digging its own grave, with the help of its “ intellectuals.”