What is that empirical data? I'm curious, not being snide.
Some raw data http://www.epi.org/publication/bp359-guestworkers-high-skill...
A good analysis of several data sets with links to raw data http://spectrum.ieee.org/at-work/education/the-stem-crisis-i...
Nearly everything I've read indicates that immigration doesn't really hurt wages, except perhaps those of recent immigrants.
What is that empirical data? I'm curious, not being snide.