Chennai: With their US citizenship remaining uncertain, thousands of immigrants mainly from India and China are contemplating returning to their home countries. As a result the US faces the prospect of brain drain.

This time US will be a bigger loser as those who intend to return to their countries are skilled and experienced professionals, states a study titled, Intellectual Property, the Immigration Backlog, and a Reverse Brain-Drain -- America's New Immigrant Entrepreneurs, Part III, released by the US-based The Ewing Marion Kauffman Foundation.

The research study looked at the number of patents filed by the immigrants, the backlog in immigration, the link to the possibility of people going back to their native land and the resultant impact on the US.

Approximately one in five new legal immigrants and about one in three employment principals either plan to leave the United States or are uncertain about remaining, the study states citing an earlier research, New Immigrant Survey. Already the trend of Indians and Chinese immigrants leaving to go home is being witnessed owing their booming economies.

The latest study on the US immigration backlog, intellectual property and the reverse brain drain states that more than 1 million individuals are waiting in line for legal permanent resident status. The wait time for visas for countries with the largest populations, like India and China, ranged to four years in June - not counting visa processing time - and may be even higher when visas are again available in October.

This backlog is likely to increase substantially, given the limited number of visas available. Approximately 120,120 permanent resident visas are available annually for employment-based principals and their family members in the three main employment visa categories (EB-1, EB-2, and EB-3).

Additionally, the number of visas that can be issued to immigrants from any one of
the major sending countries, China, India, Mexico, and Philippines, is less than 10,000 per year (7 per cent of the total pool of 120,120 available visas per country).

"It is a lose-lose situation for the US; first we lose critical talent that is helping the US compete globally and second, they become our potential competitors. We brought hundreds of thousands of workers to the US on temporary visas, trained them in our technology and market and now we are forcing them to leave - just when they have become even more valuable", remarks Vivek Wadhwa, Wertheim Fellow, Harvard Law School, executive in residence, Duke University.

The research report is authored by Wadhwa along with Professor Guillermina Jasso, New York University, Ben Rissing, research scholar and project manager, Pratt School of Engineering, Master Duke University, Professor Gary Gereffi, director, Center on Globalisation, Governance & Competitiveness, Duke University and Richard Freeman, director, Labour Studies Programme, National Bureau of Economic Research, Havard University.

The Kauffman Foundation study states that foreign nationals residing in the US were named as inventors or co-inventors in 25.6 per cent of international patent applications filed from the country in 2006. And 16.8 per cent of that had an inventor or co-inventor with a Chinese-heritage name. The contribution of inventors with Indian-heritage names was 13.7 per cent showing an increase from 9.5 per cent in 1998.

Both Indian and Chinese inventors tended to file most patents in the fields of
sanitation and medical preparations, pharmaceuticals, semiconductors, and electronics.

According to Wadhwa, a part of the problem has been created by the US expanding the numbers of temporary workers (H-1B visa) and not increasing the numbers of permanent resident visas. "If the US needs skilled migrants, it should bring them here to stay and not as temporary workers."

He says the yearly inflow of talent from the world to US is worth billions of dollars when one factors the cost of educating a skilled professional from childhood to the time they get a degree and multiplying that number with the number of such workers coming to US. "It could be that India has provided more in intellectual-capital to US just over the last decade than all of the financial aid the US has given to India over the last 60 years."

According to earlier studies, the one in four engineering and technology companies founded between 1995 and 2005 had an immigrant founder mostly educated in science, technology, math and engineering related disciplines with 96 per cent holding bachelor's degree and 75 per cent holding master's or doctorate degrees.

These companies employed 450,000 workers and generated $52 billion in revenue in 2006.