The current U.S. administration is openly hostile toward Chinese researchers and students. FBI Director Christopher Wray said in February that Chinese academics and scientists posed a “whole-of-society” spying threat, after which the State Department shortened visa stays from five years to one for Chinese grad students in sensitive fields.

The president himself was reported last month to have told corporate executives that “almost every student that comes over to this country is a spy,” apparently in reference to Chinese students.

This hostility is one reason why Chinese students and researchers are now staying home, according to a Thursday piece in the South China Morning Post. It’s not the only reason though.

Among researchers, probably an even more significant factor is the fact that the pay is now much better in China than in the U.S., the destination for more than half the Chinese students who opted to study overseas last year. In one case cited in the piece, a postdoctoral research fellowship in China came with pay of more than $87,800 a year, whereas the average package over in the U.S. was just $47,000.

“The problem of the brain drain no longer exists. One important reason is the salary. Another reason is Trump,” Chen Guoqiang, director of the Centre for Synthetic and System Biology at Tsinghua University, told the Morning Post. “Unless there is an irresistible offer, such as a post in a very, very top laboratory, most people choose to avoid America.”

According to a Chinese education leader quoted in a Times Higher Education report in March, a decade ago seven Chinese students were leaving for every one that returned, but today six in seven students return.

Another factor appears to be recent improvements in Chinese universities, which have now given the country sixth place in the Times Higher Education global rankings. The Chinese Academy of Sciences recently said it would review its talent evaluation system, to correct a bias that favored those who went abroad to study.