In 1982, foreign-born engineers constituted about 3.6% of all engineers employed in the United States, 13.9% of which were naturalized; and foreign-born Phds in Engineering constituted 15% and 20% were naturalized. In 1985, foreign-born Phds represented almost 33% of the engineering post-doctorate researchers in US universities. Foreign-born Phd engineers often accept postdoctoral positions because other employment is unavailable until green card is obtained. A system that further incentivising replacement of US-citizens in the upper echelons of academic and private sector engineering firms due to higher educational attainment relative to native-born engineer who for the most part do train beyond undergraduate level.