For one thing, it really is only “from France to Sweden”—aggressive state pro-natalist policies have shown little effect outside the narrow geographic corridor from France to the Nordic countries. In many other places and times—from Soviet Russia to modern Singapore—governments have tried all sorts of policy innovations to encourage family formation and childbearing. There have been tax breaks for parents, years-long paid maternity leave, the awarding of big cash “baby bonuses”—even attempts to subsidize the housing of grandparents so that they could take care of the kids in order for mothers to return to work. The places where the policies have been most successful are France and the Nordic countries. So the successes have been geographically and culturally localized while the instances of failure have spanned the globe.

And how successful have these policies been in France and the Nordic states? Well, the replacement fertility rate is 2.1, which is the number of children born, per lifetime, to the average woman. In Sweden the fertility rate today is 1.67. In Switzerland it’s 1.53. In Norway it’s 1.77. In the Netherlands it’s 1.78. In Finland it’s 1.73. Only France is in spitting distance of replacement, with a total fertility rate (TFR) of 2.08. In other words, the “successes” Harney points to aren’t just localized—they’re not even all that successful.

With the exception of France, of course. France has been obsessing about its fertility rate and pursuing pro-natalist policies since 1938. However, it’s pretty clear that the single most successful aspect of France’s pro-natalism hasn’t been free daycare for working mothers and encouragement of women in the workforce. It’s immigration. Native-born French women have a fertility rate of 1.7—just about what you see in the Nordic countries. France’s big fertility boost comes from its large immigrant population, whose fertility rate is a gaudy 2.8.