Thread by @tgrayeb

So after looking at a bunch of stats here’s a (fairly long) thread on my thoughts re Japanese demographic decline: married Japanese couples actually have a lot of kids – more than couples in almost any other rich country.

What seems to actually differentiate Japanese (and Korean) demography from the rest of the rich world is not so much low immigration or even low marriage rates, it’s the incredibly low proportion of children born out of wedlock.

That’s not to say Japanese marriage rates aren’t low, but they’re not significantly different from other rich countries. Japan’s marriages-per-year rate is actually above the OECD average, and Japanese people are getting married younger than many Europeans.

And while the proportion of Japanese people aged 15-49 who are married (48.6%) IS in the lowest quintile of OECD countries, it’s not drastically far off from the 53% average. It just doesn’t strike me as a gap big enough to be dispositive.

These are not new facts, and have been talked about in a handful of op-eds, but when I saw the numbers in my first graph I was still amazed at how drastic the difference between Japan’s in-marriage and outside-marriage birthrates are.

And looking at the data, I’m not convinced that “low marriage rates” is a viable explanation. Even if you increased Japan’s marriage rate to 62.3%, making it the highest in the OECD, net birthrate still wouldn’t break 10 per 1000. It’d still be among the lowest in the world.

It is worth mentioning that the percentage of the population aged 15-49 is lower in Japan (~42%) than any other OECD country (avg. ~46%), which itself drags down birth rates. But that doesn’t explain how the demography got that way – just how far these trends have advanced.

In 2017 there was some talk about a study which suggested that 19% of Japanese adults under 50 had never been married, but the 2012 US census said the same thing about 20% of Americans 20 and up. And a 2015 Eurostat study said that 28% of Europeans 20+ had never married, either.

A lot gets said about immigration, but that doesn’t seem like a serious differentiating factor to me. Japan’s net migration rate and percentage of the population that’s foreign-born are low, to be sure, but still roughly comparable to many Central European countries.

So that brings me back to out-of-wedlock births. Last year I had a class with Mark Ramseyer, who mentioned that the ratio of kids born out-of-wedlock was lower in Japan (~2%) than the rest of the OECD (avg. ~39%).

Prof. Ramseyer guessed that if you looked at kids born in-wedlock per 1000 people it would look similar to other rich countries. Lo and behold, he was right. Japan’s in-wedlock birthrate is actually above the OECD average.

If Japan had an out-of-wedlock birthrate on par with the OECD average, its net birthrate would be the 7th highest in the group. In actuality, Japan is last. This has actually been talked about a bit in Japanese media: newsweekjapan.jp/stories/world/…

I reached my original babies-per-couple-per-year ratio by taking the births-per-1000 numbers and paring down the births by the in-wedlock ratio and dividing the 1000 first by the percentage of people ages 15-49 and then by the percentage of that group who are married.

The final population number is divided by 2 because, well, couples. But the end result is that if you had 1000 people representative of the Japanese population, you would have 101 married couples aged 15-49 having 7 to 8 kids a year.

By comparison a 1000-person United States would have 115 couples in that age bracket having 7 kids a year. In France it’s 119 couples having 5 kids a year.

But in those countries the unmarried people are having kids too – sometimes more kids than the couples. Not so in Japan (and South Korea). I don’t really have any hypotheses about why that is and I’m not going to try to guess.

It’s worth making a disclaimer that I’m not advocating any policies or making any value judgments here, just trying to parse some statistics that can help make sense of Japan’s oft-discussed demographic crisis.

You frequently see the population decline attributed to things like low immigration, marriage rates, work culture, expectations of women, those darn kids, etc. Most of which probably play their own part but none of which quite match up with all the data.

And of course many of those things can contribute to explanations of why there are so few out-of-wedlock births in the first place. But that’s the question I’m interested in seeing more perspectives on.

There’s an endless stream of articles and mini-documentaries in the foreign press asking “why is Japan’s birthrate so low?” But looking at the data this way, it seems to me that the question could/should be narrowed to “why are *unmarried* Japanese having so few kids?”

You could even ask “why do married Japanese couples have SO MANY kids?” Though I imagine most people wouldn’t really care as much about the answer to that, given the demographic situation at hand.

So this is just my personal take on things based on the demographic data I’ve been able to find.