The money supply is the total amount of liquid or near-liquid assets in the economy.
The Federal Reserve, or the Fed, manages the money supply, trying to prevent either recession or serious inflation by changing the amount of money in circulation.
The Fed increases the money supply by buying government bonds in the open market, and decreases the supply by selling these securities.
In addition, the Fed can adjust the reserves that banks must maintain, and increase or decrease the rate at which banks can borrow money. This fluctuation in rates gets passed along to consumers and investors as changes in short-term interest rates.
The money supply is grouped into four classes of assets, called money aggregates. The narrowest, called M1, includes currency and checking deposits. M2 includes M1, plus assets in money market accounts and small time deposits.
M3, also called broad money, includes M2, plus assets in large time deposits, eurodollars, and institution-only money market funds. The biggest group, L, includes M3, plus assets such as private holdings of US savings bonds, short-term US Treasury bills, and commercial paper.
The size of the money supply is an important determinant of the level of spending in the economy and its control is a particular concern of MONETARY POLICY. However, the monetary authorities have a problem because given the number of possible definitions of the money supply, it is difficult for them to decide which is the most appropriate money supply category to target for control purposes. Moreover, having targeted a particular definition they face the added difficulty of actually controlling it because of the potential for asset switching from one category of money to another.
For most of the 1980s the authorities targeted M3 for control purposes, but in recent years have switched to M0 and M4 as ‘indicators’ of monetary conditions in setting ‘official’ INTEREST RATES (see MONETARY POLICY COMMITTEE). See LEGAL TENDER.
The size of the money supply is an important determinant of the level of spending in the economy, and its control is a particular concern of MONETARY POLICY. The monetary authorities have a problem, however, because, given the number of possible definitions of the money supply, it is difficult for them to decide which is the most appropriate money supply category to target for control purposes. Moreover, having targeted a particular definition, they face the added difficulty of actually controlling it because of the potential for asset-switching from one category of money to another. For example, if the authorities target M3 (mainly currency plus bank deposits) for control purposes, this may not be sufficient in itself to reduce spending. Spenders may simply use their building society deposits (M4 type money) or national savings (M5 type money) to finance current purchases.
In the 1980s the UK government, as part of its MEDIUM-TERM FINANCIAL STRATEGY, set ‘target bands’ for the growth of, initially, sterling M3 and later M0. In recent years, formal targeting of the money supply has been abandoned, although the authorities have continued to ‘monitor’ M0, together with M4, as ‘indicators’ of general monetary conditions in the economy in setting ‘official’ INTEREST RATES (see MONETARY POLICY COMMITTEE). See LEGAL TENDER.