Can any of you very astute gentle persons help me to figure out my conundrum. I'm trying to figure out what the "true" tax is when I pay through out the year until it's fully paid. It seems to me that the government is collecting interest on half-the-amount for the entire year but I only get credit for the stated amount. Where does this "interest" go? (This is what happens to a 70 year old man who has lot's of time to think about "strange" paradoxes.)