Whoops, The Report was Only Off by $700 million?

Here is an article buried in the Arizona Republic about how the report from the Udall institute sites by Robert Robb here was not just 'revised' a little.

University of Arizona researchers understated the amount of state taxes
generated by immigrants by more than $700 million in a study released July 11,
they said Friday.

This still doesn't take into account the other economic impacts I site here. To me, this shows two things: One, how difficult it is to measure the economic impact of a large group of people. Two, everyone should be sceptical of data cited anywhere to support a political agenda (including here, Hell, especially here).