I'll settle for an answer to this question: "Dr. Sowell, unemployment is very low right now. What will the probable effects be of the removal of 11.5 million workers from the country on the GNP?" As a starting point, I'd suggest taking Alan Greenspan's statements to the Senate in 2003 and 2004 on immigration. You may reply when ready.
UPDATE: Saying that "studies don't produce knowledge" is a cheap shot when you don't point to problems in the study. Pew Hispanic center's study on the benefits of immigration was hardly the only one out there that showed positive effects of immmigration on the national economy. And you're dodging the question I asked. Try again. (It's in paragraph two.)