"Neither the government nor corporations make tax returns public, and a company’s taxable income often differs from the profits disclosed in annual reports. Companies report their cash outlays for income taxes in their annual Form 10-K, but it is impossible from those numbers to determine precisely how much, in total, corporations pay to governments. In Apple’s last annual disclosure, the company listed its worldwide taxes — which includes cash taxes paid as well as deferred taxes and other charges — at $8.3 billion, an effective tax rate of almost a quarter of profits.
However, tax analysts and scholars said that figure most likely overstated how much the company would hand to governments because it included sums that might never be paid. “The information on 10-Ks is fiction for most companies,” said Kimberly Clausing, an economist at Reed College who specializes in multinational taxation. “But for tech companies it goes from fiction to farcical.”
Yes, it's pretty much speculation. But it makes for good theater: NYT has put together an accusing graphic to provoke a sense of outrage:
More to come on the subject.