【明報專訊】Quantitative easing can be understood as "pumping money into an economy and working to lower interest rates that central bankers do not usually control" so that banks can make loans, which will stimulate economic activity. The commonest way of QE is to purchase debt (債券) on a large scale. Doing so has the same effect as printing vast quantities of money, but the authorities need not turn on their printing machines. It may be called "expanding the balance sheet". The Fed buys government or other bonds and "writes down" that it has done so. After making the money available to lenders, the amount of money sloshes round the economy, which may expand.