SAN DIEGO (Border Report) — U.S. Secretary of State Marco Rubio recently estimated that as many as 50,000 Chinese students enrolled in California colleges and universities could have their visas revoked in the near future.

President Trump has said the Chinese students are “exploiting U.S. universities,” outlining policies his administration calls “Put America First, Not China.”

At schools like the University of California at San Diego, close to 18 percent of the student population is made up of international students, many from China, according to UCSD assistant professor of economics Guarav Khanna.

Khanna has researched the impacts of foreign students on universities and college towns in the U.S.

“They are very important sources of revenue, and this is particularly important at public universities, they pay full-fee tuition and they essentially cross-subsidize local in-state students,” Khanna told Border Report. “They make attending school cheaper for local students.”

Khanna also says his research shows international students are a boom for the U.S. economy.

“They are buying cars, renting apartments and that helps the local economies that surround these college towns — when they graduate, they have a pretty big impact on the U.S. economy because they are often working in these high-tech sectors and STEM-fields sectors that cause innovation.”

Cal Matters recently published an article detailing how revoking visas for Chinese students will have severe consequences for the state of California.

According to Khanna, many Chinese students at schools such as UCSD are facing a lot of uncertainty and stressful times.

“Think about it, you’re a college student and someone suddenly says you can’t be in this university, you can’t be in this country, it will change their entire life so they might be looking at other avenues, their home country or in other destinations such as Canada, the U.K. or Australia.”

The White House policy does not mean every Chinese student will have their visas revoked, but it does mean all will have to face more scrutiny and background checks, Khanna says.

“They are going to check their social media, things like that and we’re going to start aggressively revoking visas of Chinese students that are part of the Communist Party or part of an institution that has links to the military in China.”

Over the last few months, thousands of international students have lost their visas after participating in protests or for getting traffic citations or other minor infractions.

According to Politico, Rubio has asked U.S. embassies to stop scheduling all new visa interviews for international students.