This must be one of those cosmopolitan elites I’ve been hearing about

I think Mr. Yglesias is a pretty smart guy, and his posts on Iran of late have been admirably sane, which makes his confused recent posts on national birthrates all the more surprising. I can only assume he’s being willfully obtuse when he writes that

I think part of what drives these anxieties is the intuition that if birth rates fall and fall eventually the human race will dwindle to nothing.

But of course! All those people anxiously observing demographic changes throughout the world actually fear a Children of Men scenario. All those last-man-on-earth sexual fantasies certainly couldn’t compensate for the incapacity to field a halfcourt pickup game (please — no WNBA jokes).

An alternate theory holds that people are specifically concerned for their own birth rates — particularly relative to other potentially competitive nations (cf. France vs. Germany through the second half of the 19th century). Nor, I think, is this merely a politico-military challenge. I always find it curious when the same people who would never dream of banning theories of evolution from the classroom steadfastly refuse to infer any actual significance from them.

Part of that whole evolutionary imperative involves the necessity of passing on our genes. If not us personally, then our family. If not our family, then our closest match (as opposed to the guy on the other side of the world), and so on.

I know of no reason why this ceases to be the case simply because we as a society have reached an advanced stage of modernization. Granted, we no longer need to have 8-10 children because we don’t know who will make past adolescence or we need the labor, but it would still be nice to avoid sub-replacement fertility.

Mr. Yglesias notes that

a developed country that did find itself in desperate need of additional workers can always let more immigrants in.

Ah yes, we can always import a helot class. Or perhaps Rome is your preferred ancient analogy? While it’s true that Dalmatia supplied some of Rome’s better late-period emperors, on the whole its policy of bolstering its depleted population (particularly military) via immigration didn’t turn out too well.

The fact that demography-watchers on the right go against their own political beliefs (as Mr. Yglesias rightly notes) in warning those across the aisle of the instability of the welfare state in the face of falling birthrates only goes to show how this fundamental issue transcends ideology.

While I don’t think much of Georgia’s Romanian solution, there are a handful of material drivers throughout history that you really can’t mess with. Demography is one of them.

UPDATE: Nicholas Eberstadt has a related piece on Russia’s considerable demographic troubles.

(Hat tip: Ross Douthat)