Americans not particularly interested in economics might not give much thought to other countries' experiments with negative rates, especially now that we seem to have the opposite problem. They probably should. It is hard to call the long, strange trip of rates below zero a success, but it didn't blow up markets either. The next time there is an emergency, or maybe the time after that, central banksincluding the Federal Reservecould go back to the negative-rate drawing board. Forcing people to spend Economists have long wondered how to jump start an economy that won't respond to even very cheap borrowing costs. Forcing people to spend instead of saving their money was one of their ideas, but it wasn't practical until recently. And, even if it made sense on paper, it upended people's historic understanding of money. The first interest payment was recorded in ancient Babylon more than 4,000 years ago. Almost since people gave up bartering, money, in whatever form, has served at least two purposes: a medium of exchange but also a way to store up the fruits of their labor to buy something in the future. Matching that deferred consumption up with people or governments that wanted to spend money they didn't have yet is where interest came in. Into uncharted territory Earning something for your cash was a way to reward you for parting with it temporarily and compensating you for the risk it might not get paid back. That price has fluctuated, but it was always a positive number