Rising Fertility in Highly-Developed Countries

I’ve always suspected that the link between economic development and fertility is more complicated than the standard story of inverse relationship. Increased economic opportunities increase the opportunity costs of having children, and this decrease fertility. Counterbalancing this, though, is the possibility that kids are a normal good in the sense that demand increases with income: as we get richer, we are more willing to give up income to have kids. Additionally, advances in IT seem to be pushing down the opportunity cost of children by making flexible work arrangements (particularly telecommuting) more feasible. It’s possible that at some point the pro-natal factors could come to dominate the anti-natal.

According to some new research published in Nature, there does seem to be a development threshold above which the standard relationship is reversed [WaPo story, gated nature article, annoying ungated version]. The results indicate that the standard story remains true for most countries, but once countries reach a very high level of development – around 0.85-0.9 on the Human Development Index – fertility begins to increase.


If this trend is real and continues to higher levels of development, the long-term relationship between development and fertility should be U-shaped (or maybe even J-shaped!). As someone who likes people and would like to see as many of them as possible, I think this is great news. The Simonian future of a trillion humans might not be quite so far off, after all.

Hat tip: Contexts Crawler

5 Responses

  1. Wow, a trillion humans – what a Utopia! (that’s sarcasim if not obvious)

    • Did I mention they’ll all be good-looking, polyamorous, immortal cyborgs? Well, apart from the primitivist terrorist cells. Those guys will continue to be an annoyance. Some of the less enlightened of us will hunt them for sport.

  2. So kids are a bit of investment and a bit of consumption and the importance of the two bits changes as income increases?

    • I’d say they’re mostly consumption goods in developed countries (where everyone is pretty much capable of taking care of their own retirement). The decreasing importance of the investment aspect surely has an effect on some less developed countries, but I doubt it’s significant in the trend I point to here.

      Cost has been going up with foregone employment opportunities, but is now falling somewhat with IT; and demand is increasing with income.

  3. There are some serious doubts about the Nature paper’s conclusions, including substantial statistical bias in their methodology. See my recent guest post on the Stubborn Mule:

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