Rock Center Fellow Vivek Wadhwa discusses how visa hurdles and other obstacles on the road to permanent residency are forcing many foreign Silicon Valley entrepreneurs, and the jobs they generate, out of the U.S.

In this edition of Need to Know, the program explores the debate about legal immigration.

First: should the government make it easier for foreign-born, hi-tech workers to stay in the United States, as companies like Google, Facebook and Microsoft argue? Or are these workers already undercutting the job market for Americans? Need to Know’s Rick Karr travels to Silicon Valley and to New York City to investigate.