If you trade with a faction we can assume that civilisation interact with each other, but normally we would see people traveling betwenn empires and migrate, but in the game that doesn't work at all, so I was thinking about a way to trade popultion in diplomacy, after all we allready can exchange manpower, so why not popluation ? 


That could be a way of getting ride of unwanted population without genocide (like everyone is shoutting about since  a longtime) or to take a popultion you need or what.


I see it to be two thing : 

- Each type of popultaion is use as a ressource likes strategique and luxuries

- We got a special action that propose one of their pop against one of the player pop