When Tradition Tries to Overrule Demography

I was off from work today, catching up on various personal projects as well as catching up on my neglected blog feed reading - and I saw that Andrew Gelman recently wrote about a museum exhibit in France that included a set of pronatalist posters from the 1920s. The material was produced by the Alliance nationale pour l’accroissement de la population française, a group that spanned the political spectrum at the time. Their message was simple: a “normal” family should have three children. The posters framed this as a national necessity.

The exhibit highlights a recurring pattern in demographic reasoning. Once a society reaches low infant and child mortality, the long‑term replacement level is about 2.1 children per woman. The posters didn't reference this. Instead, they promoted a target that was higher than what stable population dynamics require. The intent was not stability. It was growth. France had just come out of the First World War and was concerned about falling behind Germany in population and industrial capacity.

Gelman points out that the “ideal number of children” is not the same as the number people actually have. Ideals often reflect cultural narratives rather than lived behavior. The posters treated the ideal as a factual requirement. They also ignored the distribution of family sizes. Some households have no children or only one. Policymakers may have assumed that others needed to compensate by having three.

The comments on the post add useful context. One reader notes that the poster’s population pyramid shows an expansive structure rather than a stable one. Another points out that immigration is not considered at all. Others mention that similar rhetoric persists today, including recent French political language about “demographic rearmament.”

The exhibit is a reminder that demographic claims often blend arithmetic with ideology, something that touched a chord for me particularly after just publishing my book which also explores some similar themes . When governments promote a specific family size as a national duty, the argument usually rests on selective assumptions about stability, growth, and identity. Gelman’s post shows how easy it is for a cultural ideal to be presented as a demographic fact, even when the numbers tell a different story.