Appendix A
An Examination of the Assumption of Zero Immigration
The assumption of zero immigration was essentially limited to members of this workforce who received their doctorates from foreign universities since the SDR covers a subset of non-U.S. citizens who graduate from U.S. institutions (i.e., those who do not report at the time they receive their degrees that they plan to return to their countries of origin). Data from the National Survey of College Graduates can be used to derive a crude estimate of immigration. In 1993, roughly 11 percent of the doctoral population in fields classified as biomedical science earned their degrees from foreign institutions. The comparable percentage for fields classified as behavioral science was slightly less than 2 percent (NSF 1994).
In addition to the foreign nationals who earned their doctorates abroad, a substantial number of non-U.S. citizens earn their doctorates from American institutions. Between 1963 and 1983, roughly 20 percent of the doctorates in the life sciences from U.S. institutions were awarded to non-U.S. citizens. After 1983 the share increased steadily; it rose to 28 percent in 1988 and 35 percent in 1993 (NRC 1995, 21). Although the SDR attempts to capture those who stay in their sampling frame, it fails to capture (1) those who indicate at the time they receive their degrees that they plan to return to their native countries but remain in the U.S., and (2) those who actually return to their native countries after receiving their degrees but who subsequently come back to the U.S.
A recent study estimates that roughly 40 to 45 percent of the foreign nationals who earned doctorates in the life sciences from U.S. institutions in 1984 and 1987-1988 were working in the United States in 1992 (Finn and Pennington 1994). These data suggest that roughly 10 percent of the life science workforce might be non-U.S. citizens who received their doctorates from American institutions. This is reasonably consistent with the estimate generated by the National Science Foundation from the National Survey of College Graduates. Data reported on this survey indicate that in 1993 about 11 percent of the Ph.D.s in biomedical fields had received their degrees from American institutions.
A comparable estimate was not generated for the behavioral sciences because they were not broken out separately in the Finn/Pennington study. Instead, they were included in the aggregates for the social sciences. It seems likely, however, that non-U.S. citizens who earned doctorates in the behavioral sciences will constitute a
smaller fraction of the behavioral science workforce. This conjecture is supported reasonably well by data from the National Survey of College Graduates that indicate that about 8 percent of the doctorates in behavioral science fields were foreign citizens who received their degrees from American institutions.
References
Finn, Michael, and Leigh Ann Pennington 1994 Foreign Nationals Who Receive Science or Engineering Ph.D.s from U.S. Universities: Stay Rates and Characteristics of Stayers . Oak Ridge, TN: Oak Ridge Institute for Science and Education.
National Research Council (NRC) 1995 Summary Report 1993. Doctorate Recipients from United States Universities. Washington, DC: National Academy Press.
National Science Foundation (NSF) 1994 1993 National Survey of College Graduates, Special Tabulation. Arlington, VA: NSF.