The Center for American Progress says it will improve American household incomes by $189 billion/year.
[I]t is worth noting that very different think tanks employing two different models have come to the same result: Legalization of immigration will expand the U.S. economy and incomes, while an “enforcement only” policy of further restrictions will only depress economic activity.Quoting CAP:
The U.S. government has attempted for more than two decades to put a stop to unauthorized immigration from and through Mexico by implementing “enforcement-only” measures along the U.S.-Mexico border and at work sites across the country. These measures have failed to end unauthorized immigration and placed downward pressure on wages in a broad swath of industries.Comprehensive immigration reform (CIR) would benefit the US economy by something on the order of $2.5 trillion (the studies agree).
Oh, and that fantasy of stuffing all the undocumented into boxcars and shipping them out of the country?
Mass deportation reduces U.S. GDP by 1.46 percent. This amounts to $2.6 trillion in cumulative lost GDP over 10 years, not including the actual cost of deportation.