I don't have a source either, but this has been a concerning trend since around 9/11. First, there is the perception that "things are improving" back in the mot

I don't have a source either, but this has been a concerning trend since around 9/11. First, there is the perception that "things are improving" back in the motherland. The middle class is expanding, and the quality of life is improving. Second, it's hard to get work visas in the US, and there is the perception of hostility towards foreigners (Bush's wars, Trump's election, etc). The "reverse braindrain" is a serious problem that the US is experiencing in recent years, because the educated foreigners have chosen to get the hell out or have been forced out. I know a few Chinese with graduate degrees in engineering who are considering returning to China after banking a few more years of American wages. They are heading back to an environmental disaster, but oh well, "progress".