Andrew Follett says the U.S. tax code penalizes uneven income streams, with taxpayers earning the same $500,000 over five years facing sharply different bills.

Andrew Follett says the U.S. tax code penalizes uneven income streams, with taxpayers earning the same $500,000 over five years facing sharply different bills. A steady $100,000 earner pays $67,500; income concentrated in year five can top $100,000.