lending, turns the actual operation of the monetary transmission mechanism on its head. At all times, when banks ask for reserves, the central bank obliges. According to this model, reserves therefore impose no constraint and the deposit multiplier is therefore a myth. The authors therefore argue that private banks are almost fully in control of the money creation process. John Whittaker of Lancaster University Management School, describes two systems used by the Bank of England. In both systems, the central bank supplies reserves to meet demand. Implications for monetary policy According to the quantity theory of money, the multiplier plays a key role in monetary policy, and the distinction between the multiplier being the maximum amount of commercial bank money created by a given unit of central bank money and approximately equal to the amount created has important implications in monetary policy. If banks maintain low levels of excess reserves, as they did in the US from 1959 to August 2008, then central banks can finely control broad (commercial bank) money supply by controlling central bank money creation, as the multiplier gives a direct and fixed connection between these. If, on the other hand, banks accumulate excess reserves, as occurs in some financial crises such as the Great Depression and the Financial crisis of 2007–2010, then according to some economists this relationship breaks down and central banks can force the broad money supply to shrink, but not force it to grow: Restated, increases in central bank money may not result in commercial bank money because the money is not required to be lent out – it may instead result in a growth of unlent reserves (excess reserves). This situation is referred to as "pushing on a string": withdrawal of central bank money compels commercial banks to curtail lending (one can pull money via this mechanism), but input of central bank money does not compel commercial banks to lend (one cannot push via this mechanism). Following the introduction of interest rates on excess reserves, a large growth in excess reserves occurred in the Financial crisis of 2007–2010, US bank excess reserves growing over 500-fold, from under $2 billion in August 2008 to over $1,000 billion in November 2009. References Sources Monetary policy