[davidw]

> If engineers are fungible, and there are many other people on the market who can do the same thing, then why have a guest worker program like H1B?

If you think it through, one reason is pretty obvious: jobs can also go to those people in wherever they happen to be born, in many cases. Letting them come to your country makes things better for everyone. Remember, the labor market is not a zero-sum game, a "lump of labor": http://en.wikipedia.org/wiki/Lump_of_labour_fallacy