A senior programmer at a fast-growing IT company, Arumbakkam volunteered for the Red Cross in Texas after Hurricane Katrina hit in 2005. He worked on disaster recovery management software to locate displaced persons, track donations and organize aid distribution.

He had hoped to start a nonprofit disaster recovery management solutions company in the United States, but now he's decided he doesn't want to wait any longer for his green card.

When professionals such as Arumbakkam give up on the States, it creates serious economic consequences, said Vivek Wadhwa, lead author of a study on the subject released last week.

"We've set the stage here for a massive reverse brain drain," said Wadhwa, Wertheim Fellow at Harvard Law School's Labor and Worklife Program.

By the end of fiscal 2006, half a million foreign nationals living in the U.S. were waiting for employment-based green cards, according to the study, released by the nonprofit Kauffman Foundation. Titled "Intellectual Property, the Immigration Backlog, and a Reverse Brain-Drain," the study was based on research by Duke, Harvard and New York University. If spouses and children are included, the number exceeds 1 million.

The study looked at the three main types of employment-based green cards, which cover skill-based immigrants and their immediate families. Including pros- pective immigrants awaiting U.S. legal permanent resident status but living abroad, the numbers hit almost 600,000 in the first group and almost 1.2 million in the second.

The number of available green cards in the three categories totals approximately 120,000. "If there are over a million persons in line for 120,000 visas a year, then we have already mortgaged almost nine years' worth of employment visas," said study author Guillermina Jasso, an NYU sociology professor.

The report also notes that foreign nationals were listed as inventors or co-inventors on 25.6 percent of the international-patent app-lications filed from the United States in 2006, up from 7.6 percent in 1998.

U.S. companies bring in many highly skilled foreigners on temporary visas and train them in U.S. business practices, noted Wadhwa, an executive in residence at Duke University's Pratt School of Engineering. Those workers are then forced to leave, and "they become our competitors. That's as stupid as it gets," he said. "How can this country be so dumb as to bring people in on temporary visas, train them in our way of doing business and then send them back to compete with us?"

Many in the engineering profession argue that American tech employers take advantage of the work visa system for their own benefit. They state that though there is plenty of American engineering talent available, employers use the programs to hire cheaper foreign labor.

And others counter the concern that large numbers of foreign residents will depart America. Most immigrants who have waited years for green cards will remain firm in their resolve, given the time and effort they have already invested, believes Norm Matloff, a computer science professor at the University of California at Davis. "People are here because they want to be here," he said. "They place a high value on immigrating."

But while Arumbakkam wants to be here, he has had enough of waiting. And his story is typical of those foreign-born tech professionals who return home.

In July 2001, the then 27-year-old Arumbakkam arrived on a student visa to get his master's in information technology at Clarkson University in Potsdam, New York. He has a bachelor's degree from the highly ranked University of Madras in southern India.

Arumbakkam said he "pretty much loved the society and the infrastructure for advanced education" in the States. In the post-Sept. 11 climate toward foreigners, however, he found it difficult to get work. After sending out countless resumes, he took an internship in Baltimore, followed by a job in Michigan.

That post didn't bring him any closer to his goal of permanent residency, however. He next took a job in San Antonio and insisted his employer secure him a green card. About that time, the government established an "application backlog elimination" center. "My application went straight into this chasm. I don't know what happened after that," he said. "That was pretty much a blow."

In 2005, he landed his current job, where he's happy with the work environment and the salary. His employer applied for a green card when the government rolled out an online system that was supposed to streamline the process.

But since then, with two applications in the works, Arumbakkam has been waiting-and waiting. In the meantime, his work status can't change, meaning no pay raises or promotions.