Selection bias or not - I am saying across any employers out there, go ahead and ask folks. Maybe you don't realize how many people in your companies are or were on H-1B and came via this route.

The H-1B program is heavily used by graduates from US institutions.

I would welcome someone actually studying this rigorously. I am confident my observations will hold. There is also no evidence to assume that Indian consulting services occupy the majority of H-1Bs.