Department of Sociology, Vanderbilt University, VU Station B351811, Nashville, TN 37265-1811, USA.
Demography. 2010 Aug;47(3):801-20. doi: 10.1353/dem.0.0117.
Between 1994 and 2006, the ratio of foreign-born scientists and engineers (FSE) to native scientists and engineers (NSE) doubled. I decompose this change into a migration effect (which accounts for migration in general), a proportional college effect (which accounts for the relative proportions of college graduates among migrant and native workers), and a proportional science and engineering (S&E) effect (which accounts for the relative proportions of S&Es among migrant and native college-educated workers). Results show that the migration effect explains about three-quarters of the increase in FSE/NSE during the entire period under study. The proportional S&E effect, which captures changes in the ratio as a result of immigration of S&Es in excess of what would be expected from general migration alone, was largest in 1995-1998, which were years of sustained economic growth. Conversely, a slower economy coincided with a declining proportional S&E effect after 2000. Increases in the annual cap on H-lB visas, an important avenue of entryforforeign-born S&Es, had little effect on the ratio. In short, during 1994-2006, the association between economic swings and the specific, more than proportional migration of S&Es was much stronger than the association between the latter and changes in the H-1B cap.
1994 年至 2006 年间，外国出生的科学家和工程师（FSE）与本土科学家和工程师（NSE）的比例翻了一番。我将这种变化分解为移民效应（解释总体移民情况）、比例学院效应（解释移民和本土工人中大学毕业生的相对比例）和比例科学与工程（S&E）效应（解释移民和本土受过大学教育的工人中 S&E 的相对比例）。结果表明，在整个研究期间，移民效应解释了 FSE/NSE 增长的四分之三左右。比例 S&E 效应则捕捉了由于移民 S&E 超过单纯移民所预期的数量而导致的比例变化，该效应在 1995 年至 1998 年期间最大，当时经济持续增长。相反，2000 年后经济放缓，导致比例 S&E 效应下降。H-1B 签证年度上限的增加，是外国出生 S&E 进入美国的重要途径，但对该比例几乎没有影响。简而言之，在 1994 年至 2006 年间，经济波动与 S&E 的特定、不成比例的移民之间的关联，比后者与 H-1B 签证上限变化之间的关联要强得多。
