“Had France’s population increased at the same rate as England’s since 1760, there would be more than 250 million French citizens alive today.”
French fertility fell from more than 4.5 children per woman to 3.5 in under 40 years, starting in the 1760s. English women were still having six. Blanc’s data comes from geni.com family trees, and the regions that dropped the Church first dropped births first. Economists credit prices and incentives. Here the cause was peasants ignoring the priest.