Vegard Skirbekk shows that many of those who were part of Europe’s population explosion died before reaching childbearing age, which is not true in the developing world. This means the European boom had a smaller impact on global population. Take one of Skirbekk’s comparisons, Denmark and Guatemala. In 1775, prior to the onset of its transition, Denmark had a population of 1 million and a population density of about twenty people per square kilometre. In Guatemala in 1900, these numbers were about the same. Because Denmark’s population boomed earlier, just two to three children per woman survived to adulthood during its transition. By the time Denmark’s total fertility rate fell below 2.1 in the 1950s, its population had expanded to 5 million. By contrast, Guatemala’s transition only began in 1900. By the 1990s, the average Guatemalan woman was giving birth to five children who survived to childbearing age. Today there are 15.5 million Guatemalans. When Guatemala’s transition is complete, it is projected to have a population of about 24 million. Its transition will have produced a population expansion five times that of Denmark. Multiplied across many countries, this explains why the West’s share of world population dropped so rapidly after 1950.
That is all from Eric Kaufmann’s excellent Whiteshift: Populism, Immigration, and the Future of White Majorities.