The U.S. Chamber of Commerce would prefer that you not know that the U.S. corporate tax code leaks revenue like a sieve. Chamber spokesman Martin Regalia complains about the media's and Sens. Carl Levin's (D-MI) and Byron Dorgan's (D-ND) treatment of a recent GAO report on corporate tax avoidance. Once again, the GAO data has been twisted and misinterpreted by those seeking to attack corporate America....Many news reports claim that the GAO study revealed that almost two-thirds of companies in the US usually pay no corporate income taxes. What the GAO report actually said was that for the period between 1998 and 2005, corporations — not necessarily the same corporations — had no tax liability for one of the eight years in question. That's totally a fair point. In fact, on the BudgetBlog last week, Adam rapped Levin for using the term "tax trickery" to explain why so many corporations had no tax liability in at least one year of the report's window. But Regalia does the smart (from his perspective) thing and avoids addressing Dorgan's point that The tax system that allows this wholesale tax avoidance is an embarrassment and unfair to hardworking Americans who pay their fair share of taxes. We need to plug these tax loopholes and put these corporations back on the tax rolls. Right. The statutory federal corporate income tax rate is 35 percent (almost 40 percent when state taxes are included), but 35 percent is really more of a theoretical construct. The tax code has so many loopholes that corporations rarely actually pay that rate on their profits. In fact, according to Tax Analysts, corporations, on average, paid a tax rate of 25.5 percent from 2002 to 2006. Additionally, the GAO report's timeframe -- 1998 to 2005 -- covers not only the "Dot Com" boom, but also the most recent recovery. By the end of 2005, firms on the S&P 500 had reported 14 straight quarters of double-digit growth. But the GAO report tells that, on average, every year within this time period some two-thirds of all corporations operating in the U.S. paid no corporate taxes. If Regalia's insistence that the GAO report does not indicate mass tax fraud -- a reasonable claim -- is true, then we should all gawk in wonder at a tax code that taxes corporations mostly in theory only.