[A. Pole]

If you can get a 170 IQ all the 140s on earth are no substitute.

People with 140 IQ are minuscule part of every population (not speaking about "170 IQ"). Also very high IQ does not correspond with very high productivity (I knew extremely bright engineers who preferred to spend their time on talking, playing games or reading books etc ...)

[JasonC]

There are 3 billion people in the newly developing world, who had no access to a serious education a generation ago but who now do. The pool of talent has expanded about 5 fold in one generation (compare educated populace today to US and Europe a generation ago). H-1bs are all about skimming the cream from the global IQ distribution and recruiting it here. The top half of 1% of that number is tens of millions people, on the order of a million fresh every year. H-1bs are 1-2 orders of magnitude smaller, again.

[Feldkurat_Katz]

I knew extremely bright engineers who preferred to spend their time on talking, playing games or reading books etc ...

I think you are making this one up...