The only answer is to give them full citizenship and make them Americans.

Economic fallacy of the make work bias. If scientists become cheap commodities, they will start to switch jobs until the salaries equalize the other options again. Case in point: In the early 1800s about 98% of the US population was in agriculture. Now the number is less than 2%. In the middle, farms started to get commodotized and it became less and less lucrative to be a farmer so farmers switched to higher paying jobs. Imagine what would have happened if 98% of us were still in farming?

I don't think that idea applies in this case.

The imported scientists have less natural job mobility than native scientists for several reasons: racism, poor English, and cultural differences.

They probably also have serious artificial barriers to switching jobs and industries because of their visas.

This law is removes the enormous artificial benefit of American citizenship (due to military, cultural and financial dominance) from one industry (science). This will change science dramatically compared to other industries.

Should a student prefer a career in an industry with artificial barriers firmly in place (like law or finance or management or even plumbing) or a career where American citizenship affords no benefit (like science or migrant farming)?

I think I'd like to be a neo-farmer in 2008. With a little land, a few solar panels and access to clean water I'm sure most of us here could make a go of it. Multi-purpose robots are coming soon - they'll be able to help out when the harvest arrives.

So you welcome [Asimov's] Caves of Steel scenario. Why not.

Added to my reading list. I'll try to track down the 1989 BBC radio version.

What kind of a future do you imagine in which science is analogous to subsistence farming?

Something like this: http://www.youtube.com/watch?v=B3DyxaCYlfg&fmt=18