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As the national debate intensifies around immigration, a new study from the University of California School of Global Policy and Strategy is challenging conventional wisdom about "brain drain"鈥攖he idea that when skilled workers emigrate from developing countries, their home economies suffer.

Published in Science, reveals high鈥恠killed emigration from developing countries may actually boost economic development, human capital and innovation in migrants' countries of origin.

With the U.S. undergoing sweeping immigration policy shifts鈥攚hich include tighter work visa rules, student visa restrictions and return migration barriers鈥攖he new research highlights how these changes will reverberate through the U.S. labor market and economies around the world.

"Global prosperity rises when countries have access to U.S. labor markets," said Gaurav Khanna, study co-author and associate professor at the UC San Diego School of Global Policy and Strategy. "And the U.S. benefits when it continues to attract the best global talent鈥攚hether it's tech innovators or trained nurses. But if we shut the door, we risk losing those global gains."

Migration creates shared prosperity across borders

The research offers compelling evidence that the opportunity to migrate to countries like the United States encourages people in lower鈥恑ncome countries to invest in education and training, creating downstream effects that strengthen both home and host countries.

The researchers also found that high鈥恠killed migrants often maintain professional ties across borders, facilitating trade, investment and innovation. Migrants returning from the U.S. to their home countries, for example, have helped connect domestic firms to international supply chains and research partnerships.

"A lot of trade works through human networks," said Khanna. "If you've worked in the U.S. and return home, you know the people, the standards, the markets鈥攁nd you can help build business relationships. That creates lasting value."

A global chain reaction

The paper documented how expanded migration opportunities can trigger a positive chain reaction. When the U.S. increased nursing visa access for Filipinos, for example, enrollment in nursing schools surged鈥攃reating nine new nurses in the Philippines for every one who migrated. Similar trends were observed in India, where increased access to H-1B visas increased the earnings of Indians in the U.S. by 10% and raised IT employment in India by 5.8%.

Khanna and co鈥恆uthors from Yale, Cornell, the World Bank, and other institutions, argue that recent changes in U.S. immigration risk undercutting both U.S. innovation and global progress.

"Earning a U.S. salary is incredibly lucrative," said Khanna, who is a faculty affiliate at the 21st Century India Center. "That motivates many people to acquire skills even if they never leave. Some eventually return home and work in their local economy; others send money back that helps educate children or launch businesses. All of this contributes to development. And for the U.S., by staying open to global talent, the country strengthens both its economy and the broader world."

To understand whether high鈥恠killed emigration helps or harms the countries people leave behind, the authors reviewed dozens of recent studies that took advantage of natural experiments. These include sudden changes in visa policies, international lotteries and other real鈥恮orld events. The authors then analyzed how people and economies changed in response to these events鈥攁nd compared them to similar groups that weren't affected.