That's incorrect. As domestic wages rise in a poor nation, emigration rises because the burgeoning middle class is better able to leave. That's why the US saw such a dramatic increase in immigration from Latin America since 1980, as wages have soared (relatively) there. The US now sees more immigration from Latin America every ten years, than it did in a century from 1880-1980. The desperately poor aren't the primary source of emigration around the world, they're mostly unable to move from their location. It's overwhelmingly not the Chinese or Indian poor (a billion people earning sub $5 per day) that are emigrating to the US, it's their middle class and higher - the truly poor can't move from their spot.

One of the most obvious examples of this - for generations, health care professionals in low-development nations have been emigrating, seeking higher incomes in the developed world. That's despite the fact that they're almost always middle class or higher in their own country. You could see this in action over the last 50 years across poor nations in Asia, Eastern Europe and Latin America. Currently the middle class is flooding out of various poor Eastern European nations, seeking a better life in eg Britain.

There were about a dozen articles posted on HN about this concept when the Syrian refugee crisis was peaking.