The Scientific American had a great article debating the increased reliance by the U.S. on foreign born STEM students entitled, "Why China and India Love U.S. Universities." An excerpt with important data follows:
Citizens of other countries now receive more than half the Ph.D.s awarded by U.S. universities in engineering, computer science and physics, on top of earning one third of all college degrees in science and engineering. In certain subfields, the disparity is much higher: in electrical engineering, for example, foreign students received 65 percent of all doctoral diplomas in 2001.
These figures should inspire alarm. The unpleasant truth is that the U.S. public education system simply does not produce enough high school graduates who are qualified for college work of any kind, let alone students with a vigorous appetite for math and the sciences. The full depth of America's educational failure is actually masked by the diversity of nationalities among grad students in those fields: Of the 1,777 physics doctorates awarded in 2011, for example, 743 went to temporary visa holders from many lands—and that figure excludes foreign nationals who had won permanent resident status. Only 15 of those 1,777 doctorates were earned by African-Americans.
The influx of students from abroad may now be reaching critical mass. Where economists used to bemoan the “brain drain” that afflicted much of the developing world, many foreign graduates are now taking their American diplomas and returning to their home countries in search of opportunities greater than those they see in the U.S. Stateside university master's programs are packed with foreign students who are scheduled to leave the country as soon as they graduate. In 2009, the most recent year for which such data exist, students on temporary visas earned 27 percent of all master's degrees in science and engineering, including 36 percent of those in physics and 46 percent in computer science. And a 2002 survey found that nearly 30 percent of those candidates had no firm commitment to lives in the U.S. after graduation. That study was conducted before the post-2007 decimation of the U.S. job market—and unless Congress can break its current stalemate, at press time, over immigration reform, the retention rate most likely will drop even further.