Part of the ongoing national debate regarding immigration reform is the question of whether to relax limits on immigration of skilled scientists and engineers. Western Europe, too, is wrestling with this question.
Advocates argue that these skilled professionals contribute to innovation and are important for economic growth. Opponents fear they may displace similar domestic workers and reduce wages.
One aspect of the immigration question is the process of permitting international students in science and engineering to enter doctoral study and to remain in the country once they complete their degrees. Most international students who earn science and engineering doctorates in the U.S. become employed here and stay, but the process of obtaining student visas and permanent residency is highly uncertain, and many talented individuals leave after graduation.
An important question is how much international students contribute to the knowledge base of the countries where they study. They may do this most directly by participating in laboratory science in research universities. In a recently published study, co-authored with A. Mushfiq Mobarak of Yale University and Keith Maskus of the University of Colorado, we made significant progress in answering that question. Using carefully structured statistical methods and a major database on 100 American research universities, we found clearly that both international and domestic students contribute strongly to the advancement of science.
Another important finding, however, is that not all foreign students are alike: fee-paying students enrolling due to economic gains were only half as productive as students who come on scholarship. We also found that it is more productive for a department to have many countries represented than to admit students from just one country.
A substantial amount of economics research shows that scientific research at universities leads to innovation and productivity gains in the private sector. So our findings imply that international students contribute to economic growth whether or not they stay.
Other studies show that immigrants with scientific and technical training continue to contribute to innovation and help raise productivity when they stay and naturalize. On the other hand, increased immigration may make it harder for U.S. citizens to start careers in science and engineering, and may reduce the prevailing level of compensation for current scientists and engineers.
Proposed legislation by both the U.S. House and Senate has suggested expanding the availability of green cards to those who earn graduate degrees in science and engineering. I think this is the right approach for several reasons. These individuals have leading-edge knowledge that can help improve what businesses produce and how they produce it. Some of them may want to use their knowledge to start a business instead of seeking employment, a step that is currently difficult unless they also are ready to invest at least $500,000. A guarantee of permanent residency would inspire more students to apply for and undertake graduate study.
Expanding permanent residency for those earning doctorates at research universities, rather than expanding the program of temporary guest workers, is a possible compromise that would have only a small effect on the job prospects and salaries of other scientists. The total number of science and engineering doctorates awarded to foreign students each year is only about 12,000, and expanding the availability of green cards would affect a fraction of those - perhaps 1,000. Allowing those 1,000 to stay in the United States would strengthen the U.S. economy in the long term.