Linda Beale is a law professor at the University of Illinois College of law who teaches various courses in the area of federal income tax--statutory construction (tax), introduction to federal income tax, corporate taxation, and introduction to international taxation.
Probably knows something about the subject.
Here's a snip from her blog, commenting on a WSJ Opinion piece by Bruce Bartlett.
Bartlett admits that many illegal aliens are poor and that the poor generally don't have to pay federal income taxes. He notes that a taxpayer who takes advantage of the Earned Income Tax Credit would need to earn about $30,000 before becoming liable for federal income taxes. Yet he seems to suggest that illegal aliens are "escaping" income taxation while not able to so easily escape sales taxes. If they wouldn't owe taxes anyway, are they really escaping taxes?
Good point, as in "D'oh..." The Journal piece is subscription only, but other references (and Ms. Beale's remarks) catch the drift of his argument. She makes a few more points worth checking out, particularly regarding the "underground economy," which circumvents taxation by cash compensation that never appears anywhere. Residential construction, for example, relies heavily on "subs," which is another way to refer to these expenses.