"As governments going as far back as imperial Rome have discovered, when cultural and economic conditions discourage parenthood, not even a dictator can force people to go forth and multiply."
He goes on to argue that those who continue to have a large number of children are decidedly politically conservative, and by Darwinian inference, destined to inherit the earth. It's really quite a neat theory. Like in economics, it is tempting to make demographic generalizations because it presents us with the illusion that we either have a definitive answer and/or a solution. However, as I have learned in the last few months, the devil really is in the details.
First problem is that, today, low fertility exists in poor and rich societies alike. Secondly, the causes of low fertility are not the same across the board - in some places, it's because it is too expensive to have lots of children, in others, it's because the government tells you that you can't. Thirdly, different societies have different appetites and capacity for change - some can adjust as they get richer, others can't. And finally, there is that massive elephant in the closet: Globalization. People the world over can increasingly choose where to live and have children, and no one could definitively tell you how this 're-alignment' will play out.
I bring up the article only because when I read it in March, I bought in to its conclusions hook, line, and sinker: it appealed to my economic sensibilities. Having been (at least partially) educated about the intricacies of demographics, it would take a lot more thoughtful analysis to convince me.