I've noticed in the past few months that fast-food establishments that never used to now have tip jars out for their grossly underpaid workers to help managements continue to avoid paying these people a fair wage. A lot of this cash -- small amounts per worker -- will not be reported as taxable income, perhaps hurting state and federal finances over time. But then, many rich folks are better than the poor at avoiding taxes, at least as a percentage of their income. Warren Buffett likes to note this, though I don't see him making many many charitable contributions to the U.S. Treasury.
Investment income is far better protected from the tax man than is earned income.
-- Robert Whitcomb