Responding to my post the other day (about the claim that entitlement programs discourage people from having kids) Ramesh Ponnuru replies here with the fair point that cultural differences among nations mean that you can't expect a perfect correlation between generosity of social program and decline in fertility. He writes: "So, for example, a country that starts with a cultural preference for large families may end up with larger families than a country without that preference, even if entitlements are larger in the latter country. The studies I cited recognize these complexities and deal with them as best they can."
Well, fair enough. These matters aren't simple (Matthew Connelly, author of an invaluable history of the population-control movement, has come to believe that we really have no idea why fertility goes up or down). But I'm now at a loss to see how Ponnuru's argument could ever be disproved. Low-fertility Germany and Russia support it (the general trend). So do high-fertility France and Norway (cultural differences). If he can generalize when it suits him but then get all particular when that suits him, there's nothing to argue about.
Ponnuru is also surprised by the commenters on my post who want to discourage people from having children. I guess he's new to the curious fact that many, many people are obsessed with the idea that other people should not reproduce. It's a curious and, I think, ugly side of human nature, and one that appears across the ideological spectrum.