Why does AI nations lose pop over time?

[Thrake]

I noticed in my last game that AI unciv at least tend to lose pop overtime, and I don't understand why, it doesn't make sense.

For exemple, Yemen starts with 100k pop and ended in 1936 with 84k (-16%) while Brunei starts with 53k and ended with 48k (-10%). I didn't check Brunei closely but I was neighbouring Yemen all along and can state they barely spent time anytilme at war, afterwards they were my spherelings and where left untouched. Most of the time they were unciv (which rules out massive migration to America) with no standing army. The only other mechanic that I'm aware of and that can explain population loss is epidemics but I don't believe that it can come up so often that it actually decrease natural pop growth.

So my question is, how in these conditions can the AI manage to lose pop? It's not just these countries, almost all unciv (didn't check civ and these are biased because of migration to America), like Punjab or Sindh seem affected.

 

[TheDungen]

Did they have many revolts? The soldiers in revolts are drawn from your pops so if you fight a lot then you may lose a lot of pops.

 

[Thrake]

No and at best it should only happen to a few countries, not globally.

 

[TheDungen]

No and at best it should only happen to a few countries, not globally.

I don't know I see many countries get uprising after uprising.

 

[Thrake]

I don't know I see many countries get uprising after uprising.

There were my neighbours (playing Persia), I noticed just a 3k rebelion in Yemen and was lookely closely at total pop to evaluate how tasty their lands were. Can't say for Brunei but Panjab, Nejd,... all seemed to lose pop out of nowhere.

Edit: loaded save game as Yemen and they have 9k rebels for pan nationalists and 6k for commies with 0 spawnable stacks. Just 2 small movements and 4.87 militancy.

They researched up to organic chemistry so should be under effect of medicine for a while.

Fun fact: the focus for their single region is for promoting bureaucrats when they already have 4.17% of that pop. No wonder why the unciv never get anything done even post westernization.

Re-edited:
And they never had a standing army anyway so they can't lose pop to rebelions.

 

[KevinG]

Certain events like cholera are more likely to occur the less provinces you have. I believe under 10 total provinces increases the chance slightly. Also the AI usually picks the worst option, so instead of losing 4% population in a tuberculosis outbreak, the AI instead opts to take the 10% loss. Since small unciv nations are usually one state, that means whenever they get hit with cholera or some other disease they will lose 10-20% of their total population. Have this happen 5 times in a game and their natural pop growth can't keep up. I've played games as civilized nations where I get hit by multiple cholera/influenza/tuberculosis/potatoes famine events so for an unciv with no medicine/organic chemistry it's easy to see why their pop keeps declining.

 

[Thrake]

Right, thanks, I guess it makes sense even if it feels pretty wrong than a country that can't get anything done because it has no pops won't try to keep them alive in an attempt to be a bit less useless than it use to be.

 

[luitzen]

Certain events like cholera are more likely to occur the less provinces you have. I believe under 10 total provinces increases the chance slightly. Also the AI usually picks the worst option, so instead of losing 4% population in a tuberculosis outbreak, the AI instead opts to take the 10% loss. Since small unciv nations are usually one state, that means whenever they get hit with cholera or some other disease they will lose 10-20% of their total population. Have this happen 5 times in a game and their natural pop growth can't keep up. I've played games as civilized nations where I get hit by multiple cholera/influenza/tuberculosis/potatoes famine events so for an unciv with no medicine/organic chemistry it's easy to see why their pop keeps declining.

Whenever I play countries like Serbia, Wallachia or Greece I usually reload when I got struck by things like cholera.

 

[KevinG]

Whenever I play countries like Serbia, Wallachia or Greece I usually reload when I got struck by things like cholera.

Smaller countries are definitely hit harder by province and state wide disease events. Cholera spreading to 5 provinces in Russia might kill 0.2% of the population but in Serbia it will kill 10-20%. Influenza is the only disease that affects big and small nations equally because all provinces get the negative modifier.

 

[wetblowdryer]

Also worth mentioning that uncivs don't experience much natural pop growth. Anything with <31 life-rating don't gain provincial growth bonuses. Many uncivs are in regions with <35 life-rating that's otherwise standard in Europe. Also, no technology bonuses, no reforms, etc. They only gain pops by conquering, or by relying upon a very very measly modifier that grows their population naturally. So, a bad event can wipe out much of their population with no way to recover. Losing 10% of your population in a German state with 40 life-rating, a few reforms, and technologies is nothing in comparison.

 

[KevinG]

Another thing to note is that most disease events fire based on a % chance for each country. This means that if if all of the Balkans is owned by turkey, the provinces there will receieve a fraction of the disease events than if the balkans broke free and splintered into Serbia/Bulgaria/Bosnia/Albania/Montenegro/Romania. 5 smaller countries get 5x the disease events of one bigger country even if they occupy the same amount of land and population.

It's honestly just bad design principles because the paradox coders aren't very statistically savvy.

 

[Thrake]

Also worth mentioning that uncivs don't experience much natural pop growth. Anything with <31 life-rating don't gain provincial growth bonuses. Many uncivs are in regions with >35 life-rating that's otherwise standard in Europe. Also, no technology bonuses, no reforms, etc. They only gain pops by conquering, or by relying upon a very very measly modifier that grows their population naturally. So, a bad event can wipe out much of their population with no way to recover. Losing 10% of your population in a German state with 40 life-rating, a few reforms, and technologies is nothing in comparison.

Ahahah, yeah, it's a wonder how these regions became populated. It's like people stopped having babies the moment they settled there and every pandemic or war is dwindling pops since then!

 

[Nicolaes]

Development rates around 30 and bad pop increase tech actually cause a general population decline in non-civilised countries.