That's the problem. It's too much immigration. Chile's population didn't go over 4.5 million until 1936, but in the game, they get millions of migrants. It gives them a very large advantage against the rest of the continent.
And frankly, there needs to be way for me to restrict emigration from your home country as well.
Yup, although they still have the same blanket modifier for being in the Americas for immigrant attraction. I'd rather they increased the North American modifier a little more and decreased the South American one.
Restricting emigration...was that actually done in this time period? The Russians definitely prevented their people from moving around, but that was because they were serfs, which also aren't properly represented in the game (should be closer to slaves than farmers, in my opinion). And slaves don't emigrate.