Hidden migration mechanics?

[General WVPM]

After playing around with the migration target modifiers, I realised there is a requirement which I couldn't find anywhere. In order to migrate from country A to country B, country B (capital only?) either has to be on a different continent than country A or country A and country B must share a border. If neither of these requirements are met, POPs can't migrate between A and B.

Are there more such hidden rules about migration?

Edit: Interesting find:
When all migration_target's have a value of 0, POPs cannot migrate, but when all country_migration_target's have a value of 0, migration works using some strange mechanic which I do not yet understand (apart from the requirement stated above).
Also it seems that only 3 countries can be picked as options to migrate to since the migration screen always displays 3 destinations at max. Edit: the 3 destinations thing only occurs when there are no modifiers at all.

 

[Jorlaan]

Yes there are migration mechanics hidden in files we're not allowed to access. I can't remember specifics but I know there are. It makes it frustrating because I've tried making migration a little more fluid and I can't.

 

[GrounchoVilla]

This is pretty odd, seeing as how many immigrants from Europe lived in places like London.

 

[guillaume88]

Is there a part of luck on which country will attract the migrants ?
I often check the migration map colors, especially in the americas: sometimes Brazil is extra green, sometimes it's Mexico, sometime Chili, etc. And I never managed to make the link with the reforms or the type of regime...

 

[General WVPM]

I've been doing some tests and can conclude that the following factors do NOT play a role*:

• Whether the origin (POP's old province) is bordering the target (POP's new country).
  
• Whether the origin is coastal.
• Target's prestige.
• Target's rank.
• Target's Reforms.
• Distance between, both between origin and new province and between countries.
• Whether the target is landlocked or coastal.
• Technology (though uncivs do not participate in external migration).
• Target's administration (both country wide and local).
• Relations between old and new country.
• Life rating.

*Unless explicitly stated in one of the files.

When removing all modifiers I expected to see an even or random or large country biased distribution of migration. But instead I noticed (in my mod) that Russians love to migrate to the ottoman empire, Transvaal and Krakow. Noone enters Russia, while the UK is being flooded.
Bavaria and most German minors get no immigrants, but Frankfurt often gets a lot.
So far my efforts to explain this behaviour have been in vain...

 

[guillaume88]

http://www.victoria2wiki.com/Migration#Country_Migration_Target

you mean that none of the value in the wiki actually work ?

 

[General WVPM]

http://www.victoria2wiki.com/Migration#Country_Migration_Target

you mean that none of the value in the wiki actually work ?

No, I mean that if you mod all the modifiers out, migration is still biased.
I'm trying to figure what extra factors come into play, for example the fact that to migrate, there must either be a shared border or the nations must be on different continents.
The values on the wiki come from the POP type files, which should work.
There is simply more happening than that.

 

[guillaume88]

I understand now what you're trying to do.

 

[Fanstar1]

No one wants to immigrate in my game

 

[grimkm]

what about wealth? Nowhere do I see access to goods or moneys..surely, most people move for this reason IRL? Or Fun?

 

[Daffius]

Most political reforms and social reforms have an immigrant attraction rate though. However they pale in comparison with the 'hidden' modifier that the new world gets. I had people emigrating from my democratic german paradise (social reforms maxed as well) to the Americas (even none democratic ones).

 

[austrianemporer]

I remembered reading from this really experienced Vicky II player/ modder (forgot his/ her name and forgot if this was 100% true) but voting reforms get certain quotas of immigrants which means certain voting reforms cause the American and Oceanic countries to get certain percentages of immigrants allotted to their voting reform group,

 

[Nerva]

When all migration_target's have a value of 0, POPs cannot migrate, but when all country_migration_target's have a value of 0, migration works using some strange mechanic which I do not yet understand (apart from the requirement stated above).
Also it seems that only 3 countries can be picked as options to migrate to since the migration screen always displays 3 destinations at max. Edit: the 3 destinations thing only occurs when there are no modifiers at all.

Sorry for the dumb question, but what is "migration_target" vs. "country_migration_target"? Where are they in the files and what do they (normally) do?

Also, from what you said, it sounds like if you zero-out the modifiers in the moddable files, it causes most countries to not get emigrants, but there are still three hidden modifiers that cause up to three countries to always get a modifier and thus be eligible for emigration. One of those might be a form of "luck" which causes the variation in targets -- every so often the game may randomly select a country on each continent to be the target of migration from other continents -- this is probably to make immigration less predictable/boring from game-to-game and year-to-year.

 

[General WVPM]

Sorry for the dumb question, but what is "migration_target" vs. "country_migration_target"? Where are they in the files and what do they (normally) do?

Also, from what you said, it sounds like if you zero-out the modifiers in the moddable files, it causes most countries to not get emigrants, but there are still three hidden modifiers that cause up to three countries to always get a modifier and thus be eligible for emigration. One of those might be a form of "luck" which causes the variation in targets -- every so often the game may randomly select a country on each continent to be the target of migration from other continents -- this is probably to make immigration less predictable/boring from game-to-game and year-to-year.

It appeared there was little to no randomness to me, since the countries were the same when each nation was equal.

The migration decision works as following, first a POP decides what sort of migration he'd like to do:

• Colonial migration
• Emigration
• Internal migration

The country_migration_target comes into play when emigrating and decides what countries are favored. migration_target determines which province within the target is favored.
The target depends on the type of migration, colonial migration is limited to your country's colonies (if any), emigration is limited to the country picked (using country_migration_target) and internal migration is limited to your country's non colonial provinces.

 

[Nerva]

What about the role of Encourage Immigration NF's? Could the AI of certain countries always choose to use that NF and thus they become an immigration target?

I know in vanilla, the Encourage Immigration NF only gives "immigrant_attract = 0.2 #increases attactiveness to immigrants by 20 %", which many people say has no measurable effect whatsoever on foreign immigration, only on internal migration.

However, in the POPs of Darkness mod, the Encourage Immigration NF gives "immigrant_attract = 1 #increases attactiveness to immigrants by 100 %" AND "global_immigrant_attract = 0.2", and having spent a dozen hours running dozens of test games on the effects, I can say with CERTAINTY that WHICH state(s) you put the NF(s) in has a measurable effect on foreign immigration -- the USA gets the largest share of foreign immigrants when the two NF's are in New York (LR50) plus Illinois (LR45), but New York by itself has a larger effect than Illinois by itself.

So, I would suggest looking into whether the Encourage Immigration NF plays a role -- it may normally be an insignificant role in vanilla compared to all the normal modifiers, but when you remove the normal modifiers as you're doing, it could be that the NF makes a big difference.

 

[General WVPM]

What about the role of Encourage Immigration NF's? Could the AI of certain countries always choose to use that NF and thus they become an immigration target?

I know in vanilla, the Encourage Immigration NF only gives "immigrant_attract = 0.2 #increases attactiveness to immigrants by 20 %", which many people say has no measurable effect whatsoever on foreign immigration, only on internal migration.

However, in the POPs of Darkness mod, the Encourage Immigration NF gives "immigrant_attract = 1 #increases attactiveness to immigrants by 100 %" AND "global_immigrant_attract = 0.2", and having spent a dozen hours running dozens of test games on the effects, I can say with CERTAINTY that WHICH state(s) you put the NF(s) in has a measurable effect on foreign immigration -- the USA gets the largest share of foreign immigrants when the two NF's are in New York (LR50) plus Illinois (LR45), but New York by itself has a larger effect than Illinois by itself.

So, I would suggest looking into whether the Encourage Immigration NF plays a role -- it may normally be an insignificant role in vanilla compared to all the normal modifiers, but when you remove the normal modifiers as you're doing, it could be that the NF makes a big difference.

The thing with the vanilla NFs is that they only make that state more attractive, which requires an immigrant to already have picked your country first.
PDM's does attract more people, because of the global_immigrant_attract, which impacts the country_migration_target.