www.anderson.ucla.edu/faculty-and-research/anderson-review/fertility
"[The researchers] chart the dates that 37 groups made the fertility transition, defined as a 10 percent decline in marital fertility."
"France was the clear pioneer, making the fertility transition at the latest in 1827 (other data suggests the transition happened at least two decades earlier). Germany made the transition in 1888, England in 1892 and Italy crossed the line in 1913. The island of Sardinia, in 1934, was the last."
"What the data don’t show is why France led the way. Wacziarg speculates that cultural ideas born in the Age of Enlightenment and developed during the French Revolution played a key role. For example, the revolution occurred with a backdrop of rising anticlericalism, which undermined the Catholic Church’s opposition to fertility controls. Also a factor, he suggests, was the way libertine novels of the 18th century spread the notion that sex could be for pleasure, not just reproduction. Whatever the root cause, he says, having fewer children became socially acceptable."
"While other factors like a drop in child mortality and a later marriage age for women also contributed, the timing of the change, in the first two decades after the French Revolution, “suggests that the social and cultural change around this momentous event may have played a role in changing fertility norms within the village,” the authors write."