By Vivek Wadhwa,
One of the most contentious issues in the skilled-immigrant debate is the H-1B visa, which allows qualified immigrants to work for U.S. tech companies on a temporary basis. Proponents of raising the H1-B visa cap say the nation faces a dire shortage of engineering talent and needs more of these visas to stay competitive. Detractors insist that there is no engineer shortage and that America should close its doors to foreigners because they take jobs away from citizens. Battles break out in Capitol Hill over the number of visas allocated because there are no hard data to back either side.