Graph of the year (decade?) so far: the economy with and without the boost from people borrowing more money against their houses while interest rates were low. If that still sounds like so much confusing math to you, the upshot is that we Americans have borrowed like crazy to keep the economy going, but that can. not. last. What we borrow, we must repay. The blue bars have to go meet the red bars down in negative land eventually. source: Calculated Risk