Population decline is far from catastrophic

... Countries from Germany to Japan are investing in mass immigration or pro-birth policies on the assumption that they must import enough warm bodies to stave off economic collapse. I think this is mistaken. Falling population on a country level is certainly no catastrophe and, indeed, may be positive. I’ll outline some reasons here.

Historically, the first question is why population declined. If it’s the Mongols invading again then, yes, the economy will suffer. Not because of the death alone, but because wholesale slaughter tends to destroy productive capital as well.

On the other hand, if the population is declining from non-war, we have a well-studied natural experiment in the Black Plague. Which is generally credited with the “take-off” of the West. Because if the population declines by a third while capital including arable land stays the same, you get a surplus. Same resources divided by fewer people....

Now, if the population’s declining not because of a terrible disaster like the Plague, rather because people simply want fewer children, then you don’t even get the massive hit from losing productive people...

So if the Plague was a per capita economic bonanza to Europe, having fewer children should be an even larger per capita bonanza.

Take Germany; before recent rises in immigration, Germans averaged 1.25 children per woman. This translates into a 1/3 decline in population per cycle (i.e every 75 years if people are living 75 years). So without immigration, Germany might expect a 1/3 decline by 2100....

The question breaks into 2 parts: absolute number of people, and changes in age composition. On numbers alone, it’s great for Germans; same physical capital, same amount of land and air and water. True there are fewer taxpayers to amortize shared costs like defense, but these costs are small and, empirically, often scale to the population anyway. For example Holland’s military budget and population are both about 1/5 of Germany’s.

So on numbers it’s great — more stuff for fewer people.

Now the second question is age profile. The key here is that a declining population means fewer working-adults to pay out pensions, but it also means even fewer kids. Who are very expensive. The number that captures both is “dependency ratio,” which is the ratio of workers to children-plus-elderly.

To take a real-world example, the UN expects Germany in 2100 to have 68 million people, compared to today’s 82 million — about a 20% decline. The age profile shifts so they expect a third more over-65’s — from 17 to 23 million. Meanwhile, children 14 and under fall from 11m to 9m. So total dependents goes from 28 million today to 32 million in 2100. Meanwhile, population age 15 to 64 goes from 54 million today to 36 million in 2100. Upshot is today a single working-age person supports half a dependent — 54 million carrying 28 million. But in 2100 that worker will support a single dependent — 36 million carrying 32 million. So far so bad, right?

... First, for over a century now people are not only living longer, but living healthy longer. This is called “health expectancy” and, sticking with Germany, is rising by about 1.4 years per decade.

This implies that 65 year-olds in 2100 will be as healthy as 53 year-olds today. While today’s 65-year-olds are as healthy as 2100’s 78-year-olds. This alone would bring the elderly numbers back down to today’s, but the lower number of children means worker burdens actually decline.

Of course, this would require raising retirement ages in line with health expectancy — 1.4 years per decade — which politicians are obviously deeply reluctant to do.

Second caveat is another long-term trend, economic growth. The irony here is that, from a population growth viewpoint, economic growth is actually the worst-case scenario. Because if the economy crashes instead, then historically the population actually soars — kids become your safety net if the welfare state goes bankrupt. So if we fail to grow, the demographic problem actually solves itself anyway. Either we grow, or population decline was a false alarm anyway.

Quantifying this growth, over the past 50 years Germany has grown 1.65% per year, real per capita. That trends puts a 2100 German worker making 4 times what they do today. Keep in mind this is likely underestimating the benefit, because any outperformance makes Germans richer yet, while any catastrophe probably makes them have more kids.

So, summing up, rising health expectancy implies there will actually be fewer dependents in 2100 Germany, while economic growth implies German workers will be 4 times richer, just on growth alone. The demographic burden plunges by 80% or more.

By the way, if you’re freaked out at the prospect of working an extra 1.4 years per decade, that economic growth alone suggests a 50% decline in worker burdens — twice the dependents on four times the income. So even if politicians are spineless, the welfare burden declines even with more dependents.

Bottom line, whether we look at total numbers or demographically, population decline coming from simply choosing to have fewer kids is nothing remotely catastrophic.

Now, a final point: in a worldwide context, more people does tend to increase investment, therefore innovation and economic growth. This is obvious in the aggregate — there wouldn’t be any factories if there weren’t any humans — but people forget.

So, on a world-wide level, we should have a bias towards more humans, while recognizing that, on a country level, a shrinking population is certainly no catastrophe.