Taking a long term view, half a century or a century out, at the rate the world is currently developing, it seems possible there will be no poor countries left to supply cheap labour. Most of the world will be wealthy, except for a few basketcases mired in warlordism and economic isolation, such as Congo, Burma, or North Korea today. Such regions will certainly have still have plenty of poor desperate people - but they will not have the education, etc., that the migrating masses driving the economies of the highly developed countries do today. They will be malnourished and illiterate and no one will want them as immigrants, just as they are unwanted as immigrants today. The rest of us seem to be on track to be part of one competitive globalized labour pool.
Based on the animation above, a half century out, 2070; the demographic disparity is significantly less pronounced in Japan.
From a US perspective going from 3.62 avg children to replacement rate (2) is much more severe than going from 2 to 1.73.
*Though, this data does put an interesting perspective on european immigration and the great depression from 1910-1930. From replacement rates, 4.24 (1880) to 2.22 (1940)
I suspect India may want them. (though with the most population in the world they may not). I work with several people from India who moved to the US, and all noticed a major quality of life drop despite much higher income just because in India you can hire servants for $1/day, so anyone with education is used to have servants making meals, cleaning the house, driving them around, and other such tasks. In most places where someone reads this there a minimum wage laws so you couldn't hire servants so cheap. (don't ask me how someone survives on $1/day in India).
The rest of us of course wouldn't know how to handle uneducated migrating masses.
