http://www.epi.org/publication/bp356-foreign-students-best-b...

But in all of these cases, studies are of interest only to determine the magnitude of the effect. We have observed thousands if not millions of times throughout history that in a wide variety of occupations, a labor shortage drives up wages and conversely, a labor oversupply eliminates wage increases (though it tends not to actively decrease wages by much, since wages are sticky upward). Increasing labor supply to minimize wage growth is an extraordinarily uncontroversial thing, and only nincompoop contrarian columnists or paid shills would argue differently.