Visa limits create 'brain-drain' in U.S.

The United States faces a "reverse brain-drain" as workers with special skills return to their home countries because of strict limits on visas, researchers at Duke and other universities say.

More than a million engineers, scientists, other skilled workers and their family members are competing for 120,000 permanent U.S. resident visas every year, the researchers at Duke, New York University and Harvard University found.

Employment visas are even more limited, with fewer than 10,000 a year from any single country. That means many people must wait years to get visas.

The result is a loss for the U.S., which benefits from foreign-born innovators, say the researchers, who released their study this week.

Duke Provost Peter Lange, the university's top academic officer, said in a statement that the findings were significant.

"We know from our own experience here that students from China, India and other nations can play an outstanding role in advancing knowledge and creating new jobs, especially in cutting-edge fields," Lange said.

Among key findings:

* Foreign nationals residing in the United States were inventors or co-inventors in 25.6 percent of international patent applications filed from the United States in 2006.

* Foreign nationals contributed to more than half of the international patents filed by a number of large, multinational companies, including Qualcomm (72 percent), Merck & Co. (65 percent), General Electric (64 percent), Siemens (63 percent) and Cisco (60 percent).

* In 2006, 16.8 percent of international patent applications from the United States had an inventor or co-inventor with a Chinese-heritage name, up from 11.2 percent in 1998. The contribution of inventors with Indian-heritage names increased from 9.5 percent to 13.7 percent.

The study is the third in a series showing how immigrants helped make the U.S. more competitive.