And Slemrod is invariably on the low end of the estimates of compliance costs. Most range around $225-250 billion - with some much higher.List them.
Tax Foundation $197 B ('02)
Economist Walter Williams - compliance costs of from $250 - $500 billion each year.
Finance Department at Baylor Univ.:
"It is well known that the U.S. income tax system has enormous compliance costs. Economists generally view compliance costs as the sum of direct payments made to tax lawyers and tax accountants for tax-related services plus the opportunity cost of time spent by everyone else. Everyone else basically includes firms and individuals who complete their own tax forms and deal directly with the IRS with respect to tax audits and litigation (rather than employ tax professionals to do the dirty work for them). A cursory survey of the tax compliance literature yields estimates (based upon this specific compliance definition) ranging from $200 to $300 billion, or approximately 1.7 to 2.5% of GDP. "
Add that to the $300 of the lead-in to this thread:
http://www.freerepublic.com/focus/news/1487572/posts?page=1
and you're easily up to $500-600 billion.