In economics, money creation is the process by which the money supply of a country or a monetary region (such as the Eurozone) is increased. There are two principal stages of money creation. First, the central bank introduces new money into the economy (termed 'expansionary monetary policy') by purchasing financial assets or lending money to financial institutions. Second, the new money introduced by the central bank is multiplied by commercial banks through fractional reserve banking; this expands the amount of broad money (i.e. cash plus demand deposits) in the economy so that it is a multiple (known as the money multiplier) of the amount originally created by the central bank.
Central banks monitor the amount of money in the economy by measuring monetary aggregates such as M2. The effect of monetary policy on the money supply is indicated by comparing these measurements on various dates. For example, in the United States, money supply measured as M2 grew from $6407.3bn in January 2005, to $8318.9bn in January 2009.