See
also: List of Economic Topics 
MONETARY
POLICY OF CENTRAL BANKS - macroeconomics
Central
banks set monetary policy. The primary objective of monetary policy is either
to influence the price of money (the interest rate) or the quantity of money.
In essence, the two approaches are equivalent; for any quantity of money, there
is an implied interest rate, and vice versa. The relationship between the price
and quantity of money is given by the demand for money.
The
central bank influences interest rates by expanding or contracting base money,
which consists of currency in circulation and banks'
reserves on deposit at the central bank. The primary ways that the central bank
can affect base money is by open market operations or sales and purchases of second
hand government debt, or by changing the reserve requirements. If the central
bank wishes to lower interest rates, it purchases government debt, thereby increasing
the amount of cash in circulation or crediting banks' reserve accounts. Alternatively,
it can lower the interest rate on discounts or overdrafts (basically loans to
banks secured by suitable collateral, specified by the central bank). If the interest
rate on such transactions is sufficiently low, commercial banks can borrow from
the central bank to meet reserve requirements and use the additional liquidity
to expand their balance sheets, increasing the credit available to the economy.
Lowering reserve requirements has a similar effect, freeing up funds for banks
to increase loans or buy other profitable assets.
A
central bank can only operate a truly independent monetary policy when the exchange
rate is floating. If the exchange rate is pegged or managed in any way, the central
bank will have to purchase or sell foreign exchange. These transactions in foreign
exchange will have an effect on base money analogous to open market purchases
and sales of government debt; if the central bank buys foreign exchange, base
money increases, and vice versa. Accordingly, the management of the exchange rate
will influence domestic monetary conditions. In order to maintain its monetary
policy target, the central bank will have to sterilize or offset its foreign exchange
operations. For example, if a central bank buys foreign exchange (to counteract
appreciation of the exchange rate), base money will increase. Therefore, to sterilize
that increase, the central bank must also sell government debt to decrease base
money by an equal amount. It follows that turbulent activity in foreign exchange
markets can cause a central bank to lose control of domestic monetary policy when
it is also managing the exchange rate.
Developing
countries may have problems operating monetary policy effectively. The primary
difficulty is that few developing countries have deep markets in government debt.
The matter is further complicated by the difficulties in forecasting money demand
and fiscal pressure to levy the inflation tax by expanding base money rapidly.
In general, central banks in developing countries have had a poor record in managing
monetary policy.
Finally,
the debate rages on about whether monetary policy can smooth business cycles or
not. A central conjecture of Keynesian economics is that the central bank can
stimulate aggregate demand in the short run, because a significant number of prices
in the economy are fixed in the short run and firms will produce as many goods
and services as are demanded (in the long run, however, money is neutral, as in
the neoclassical model). The Austrian school of economics, which includes Friedrich
von Hayek and Ludwig von Misesan argument, but most economists fall into either
the Keynesian or neoclassical camps on this issue.