Immigration is a fundamentally incomplete answer that is designed to placate people who don't want to think to deeply about the actual issues. What happens to

Immigration is a fundamentally incomplete answer that is designed to placate people who don't want to think to deeply about the actual issues. What happens to the countries they are emigrating from? Especially if we do as politicians say and "only accept the best", what does that imply happens to the emigrating nation? Are those countries stable then? And are they also now or in the future experiencing population decline? If population growth is due to being poor, is the strategy to keep them poor?