Immigrants are positive for economy

In the long-run, they expand productive capacity, stimulate investment, and promote specialization, according to Giovanni Peri, an associate professor at the University of California, Davis, and a visiting scholar at the Federal Reserve Bank of San Francisco. He also says there's no evidence that immigrants take jobs at the expense of workers born in the U.S. Peri, whose work appears in the Federal Reserve Bank's Economic Letter, reached his conclusions by looking at output, income and employment in states with heavy immigration populations and those with without. (In California, one worker in three was foreign born in 2008; in West Virginia it was one in 100.)

This implies that total immigration to the United States from 1990 to 2007 was associated with a 6.6% to 9.9% increase in real income per worker. That equals an increase of about $5,100 in the yearly income of the average U.S. worker in constant 2005 dollars. Such a gain equals 20% to 25% of the total real increase in average yearly income per worker registered in the United States between 1990 and 2007.

In general, other studies have found that the economic effects of immigration to be a net positive. Unfortunately, this is a highly political, often emotional issue that will likely transcend any Ivory Tower analysis.