The Treasury Department has published a handy summary of the CBO's immigration reform analysis. If tables are too much for you, here's the one-sentence summary: Immigration is good for the economy.
As somebody who's pointed out that the CBO cannot perfectly predict the future, let me say, once more: The CBO cannot perfectly predict the future. There is a difference between the best, most trusted, nonpartisan economic modeler we have and an oracle.
And yet: The CBO is the best, most trusted, nonpartisan economic modeler we have. And we don't have an oracle. That's why this report really matters to the debate about how this law will affect the economy. From here on, if you want to make the case that comprehensive immigration reform is bad for the deficit, bad for GDP, or bad for employment, you have to make another very difficult case: That, for some reason, you know something about the future that the Congressional Budget Office doesn't.