[zeestephen]

I don't know your particular circumstance.

My own experience is based on foreign Ph.d graduates from USA universities.

STEM graduates - science, technology, engineering, math.

About 80% of the Ph.d’s from China, India, Russia, and Eastern Europe apply for and receive Green Cards or Citizenship.

The situation is reversed for Japanese, Western Europe, and oil rich Middle East Ph.d’s.

About 80% of them return to their native country.

I assumed that was because the standard of living and employment prospects are as good as or better than in the USA.

If I am mistaken, I apologize.

[Greysard]

I assumed that was because the standard of living and employment prospects are as good as or better than in the USA.

I can think of only two reasons:

1. Graduates from Western Europe are too lazy to file papers. It doesn't cost that much, but it will take time and effort.
2. Graduates from Western Europe do not expect the USA to ever be better than their own countries. In other words, they come from stable and rich countries and expect no need for a backup home. Nothing bad happened in Europe in their lifetime, after all.

Obviously, people from China, India, Russia prefer to invest into the GC and the US citizenship "just in case." Fortunes of countries change pretty fast (ask Greece.) Having papers allows them to live in the USA and in their native countries, and to travel freely, without visas. Getting US residence papers looks like a very good idea, even if you aren't sure if you will ever live here.