Kirk Doran, Ying Shen, and I have just finished the final draft of our paper that looks at how the increase in the number of Chinese graduate students affected the productivity of their advisors in American universities. I can’t believe it’s been 9 years since Kirk and I met and began to collaborate on what turned out to be a very productive research project that examined various aspects of the productivity of professional mathematicians. (See here, here, here, and here, for some of the papers we’ve already published).
The Cultural Revolution destroyed the Chinese higher education system and China sent few students to doctoral programs abroad during those years. There was a pre-existing body of Chinese-ethnic scientists in the United States, but the flow into this group was virtually halted. After 1978, Deng Xiaoping’s reforms encouraged Chinese students to acquire their graduate training in Western universities. This policy shift led to a huge increase in the number of Chinese students studying in doctoral programs abroad, and particularly in American universities.
Our paper measures the impact of this supply shock on the productivity of their advisors in the discipline of mathematics, and the figure neatly summarizes our key findings. The number of papers published by American advisors with Chinese ancestry increased substantially after the opening up of China. Because of “ethnic complementarities,” a tendency for the Chinese students to be mentored by Chinese-American advisors, the supply shock opened up many new sources for research collaboration for these advisors, resulting in more published papers.
The supply shock also affected the American advisors who did not have Chinese ancestry. The relatively fixed size of mathematics graduate programs virtually guarantees that American graduate students were crowded out by the Chinese students. The departments that attracted most of the Chinese students were ethnically “mixed” departments–a Chinese-American mathematician was present in the department actively advising students prior to the opening of China. There was an obvious drop in the productivity of the American (i.e., non-Chinese) advisors employed in the mixed departments most affected by the supply shock. Those advisors experienced a decline in the number of students they mentored and in the number of papers they published.
The lesson is obvious, but worth emphasizing repeatedly. As is typical with supply shocks, there are winners and losers. In fact, there are winners and losers even when there are very sizable ethnic complementarities that benefit a particular segment of the scientific workforce.
The paper is forthcoming in the Journal of Human Resources.