How much population loss to not have a significant impact?

We’ve had a few apocalypse threads recently, so let me ask a related question: how much population loss could we suffer without a significant impact? Assume that the population loss is rapid and evenly spread.

I think that economically the U.K. could brush off a loss of 1% - 600K - very easily. We’ve over 2M unemployed, after all. I think 5% - 3M - would have a significant economic impact, though that’s a gut feeling and I can’t quantify it.

Then there’s the psychological impact…

Is it all over the population or is spread in certain groups? Because that is how wars have effect on populations. You might shrug off 600,000 dead all over your population, but 600,000 dead from the 18 to 25s young men (which is the group a war hits most) means 600,000 seniors leaving the work force who are not replaced, 600,000 young women without partners, 600,000 or more potential births which never take place etc.

In my OP I ask that you assume the loss is evenly spread.

A very interesting question, Sticking with the UK here’s the figures since 1960 (on the table about a screen down in the article). Over that time the crude death rate has dropped from 12 per thousand to 9.0 per thousand, indicating an annual death rate of around 1% is the normal baseline.

Personally I think doubling it (ie another 1% on top) would have an enormous impact, but would probably not preciptaite the collapse of society.

. By comparison, the 1918 Influenza pandemic killed roughly 0.5% of the UK population (disproportianatley young adults though). And while you didn’t see a total breakdown of civilisation in 1918 it certainly had an impact (albeit somewhat lost in the larger impact of the war that preceded it).

The Black Death killed off between one quarter and two thirds of Europe’s population in the mid-thirteenth century, and yet, the continent managed to recover within a few decades; in fact, many historians believe that the Plague actually benefited society in the long term.

I’m not saying that the Black Death didn’t have a significant impact, of course; but it didn’t lead to the long-term collapse of society, or to any major setback in the development of science and technology. Based on that, my answer to the OP’s question is something like 75%, as society today is more stable than it was in the Middle Ages.

I’m not so sure, I think modern society’s greater complexity and interconnectedness make it more fragile rather than less. When 90 per cent of the population were involved in subsistence agriculture and were pretty much self-sufficient for their basic needs a mass die-off was easier to shrug off.

In WWII over 16% of Poland’s population died (the highest % of any country). It made a huge impact on individuals, but I don’t think the country as a whole was devastated because of the population loss. It wasn’t shrugged, but it was withstood.

Cite: http://en.wikipedia.org/wiki/World_War_II_casualties

It depends how fast the die-off is. If it happens all at once, then yeas, I agree that we won’t make it. But if it’s spread out over a handful of years, like the Black Death, I think modern societies (and modern governments) will be able to adapt quickly enough.

Evenly distributed, I think we could pretty easily handle 5%. Economically, it doesn’t seem like that would be likely to hurt much ( the currently unemployed would fill those holes to a large extent).

Psychologically, there would be some issues, the severity depending to a large extent on what they die of (quick? grisly?), but I’d expect a recovery fairly quickly from that level at least.

There are 800-900,000 missing persons in the US annually. I am not saying they’re all dead… But as Jim Butcher mentioned in his books, that’s close enough to the herd predation rate for wild animals.