The impact of permanent residency delays for STEM PhDs: Who leaves and why

This paper assesses whether delays in obtaining permanent residency status can explain recent declines in the share of Chinese and Indian PhD graduates from US STEM programs who remain in the US after their studies. We find that newly-binding limits on permanent visas for those from China and India with advanced degrees are significantly associated with declines in stay rates. The stay rate of Chinese graduates declines by 2.1 percentage points for each year of delay, while Indian graduates facing delays of at least 51/2 years have a stay rate that is 10.6 percentage points lower. The per-country permanent visa cap affects a large share of STEM PhDs who are disproportionately found in fields of study that have been crucial in stimulating US economic growth yet enroll relatively few natives. Finally, results suggest that the growth of science in countries of origin has an important influence on stay rates, while macroeconomic factors such as GDP per capita affect stay rates only via their impact on science funding. We conclude that per-country limits play a significant role in constraining the supply of highly skilled STEM workers in the US economy.