<i>"The U.S. awarded 22,500 doctorates in natural sciences and engineering in 2007, but more than half of them were awarded to foreign nationals....The report noted that 60% of temporary visa holders who earned doctorates in science in engineering in 1997 were working in the U.S. in 2007."</i><p>Ah, sweet irony...you rarely see it put so plainly in print.  I wonder if the report noted the percentage of US natural science doctorates who have in-field employment after graduation?  It might go a long way toward explaining why US students aren't doing it anymore.<p>As one of the people who filled out the survey in 2007, I think it's telling that even today, not all of my PhD friends who graduated in 2007 have jobs in their field (and no, I don't count "post-doctoral research" as a job).  If the US wants more PhDs in the sciences, they're going to have to do something about the labor market for scientists.  Right now, it's a sucker's bet, and smart kids know it.