By JON HILSENRATH
U.K. and U.S. central bankers are trying an experiment once attempted with limited success in Japan: They can't push short-term interest rates much lower, so they're trying to revive the economy by pumping lots of money into the financial system.
This is how it works: A central bank can print money, which it does in digital form by crediting the accounts of banks with cash. In exchange for the cash given banks, the Federal Reserve and the Bank of England are scooping up financial assets -- everything from government bonds, in the case of the U.K. central bank, to commercial paper, mortgage-backed securities and other assets in the case of the Fed.
