The sinking relationship between the U.S. and China is hindering scientific cooperation, according to a new working paper from the National Bureau of Economic Research. The paper studies three measures: the mobility of STEM trainees between the U.S. and China, how often scientists in one country used works from another, and scientist productivity.

According to the working paper, Chinese graduates were 16% less likely to attend a U.S.-based PhD program between 2016 and 2019. The paper also reports a steep decline in Chinese citations of U.S. science, though finds no decline in U.S. citations of Chinese research. Finally, heightened anti-Chinese sentiment reduced the productivity of ethnically Chinese scientists in the U.S. by up to 6%.

The paper was written by Robert Flynn and Raviv Murciano-Goroff from Boston University, Britta Glennon from the University of Pennsylvania, and Jiusi Xiao from Claremont Graduate University.

While the productivity declines are still small, the authors warn the effect could grow as both sides escalate nationalist and isolationist policies.

“It’s well established that science has been becoming more and more international in recent decades,” says Glennon, an assistant professor at the University of Pennsylvania’s Wharton School and an NBER fellow.

Yet reduced talent and knowledge flows between the U.S. and China could in turn hinder international scientific cooperation. Nor have Washington and Beijing’s policies resulted in either country gaining an edge in scientific research; the NBER working paper suggests that there’s no clear “winner,” its authors write.

U.S.-China tensions over science

The U.S., in recent years, has put greater scrutiny on Chinese students and academics. The Trump administration revoked visas held by Chinese students, owing to national security concerns, and made it harder for them to get a visa to study at U.S. universities.

The FBI also launched the “China Initiative” in 2018, a program that was meant to be focused on threats such as Beijing-directed espionage and intellectual property theft. In 2020, FBI director Christopher Wray argued that the “Chinese government doesn’t play by the same rules of academic integrity and freedom that the U.S. does,” and accused Beijing of using Chinese students as collectors of intellectual property. 

Yet the China Initiative was highly controversial, as academics, universities, and advocacy groups accused the program of racial profiling and bias against researchers of Chinese descent. 

A significant number of cases were dropped or dismissed, and only a quarter of charges led to convictions, according to the MIT Technology Review. Nearly 90% of those charged were of Chinese heritage. 

The Biden administration formally shuttered the China Initiative in February 2022, saying the program was “not the right approach.” Yet Chinese officials still complain that U.S. border patrol officials are harassing inbound students at U.S. airports.

The NBER working paper’s authors note that Beijing is also to blame for the decline in U.S.-China scientific cooperation. The authors point to President Xi Jinping’s more nationalist stance, as well as instances of Chinese corporate espionage and forced technology transfers that motivated changes in U.S. policy. Still, they note that the fundamental shift was in U.S. policy toward China, rather than the other way around.

U.S. scrutiny of Chinese scientists has backfired in the past. After the Second World War, U.S. security officials stripped Chinese scientist Qian Xuesen, who worked on the Manhattan Project, of his security clearance and placed him under partial house arrest in 1950. Claims that Qian was a security threat were never substantiated. He was released in 1955, following negotiations between China and the U.S.

Qian returned to China, where he eventually jump-started the country’s rocket and space programs.