When the Bank of England changes the official interest rate it
is attempting to influence the overall level of expenditure in the economy.
When the amount of money spent grows more quickly than the volume of output
produced, inflation is the result. In this way, changes in interest rates are
used to control inflation.
The Bank of England sets an interest rate at which it lends to financial
institutions. This interest rate then affects the whole range of interest rates
set by commercial banks, building societies and other institutions for their
own savers and borrowers. It also tends to affect the price of financial
assets, such as bonds and shares, and the exchange rate, which affect consumer
and business demand in a variety of ways. Lowering or raising interest rates
affects spending in the economy.
A reduction in interest rates makes
saving less attractive and borrowing more attractive, which stimulates
spending. Lower interest rates can affect consumers’ and firms’ cash-flow – a
fall in interest rates reduces the income from savings and the interest
payments due on loans. Borrowers tend to spend more of any extra money they
have than lenders, so the net effect of lower interest rates through this
cash-flow channel is to encourage higher spending in aggregate. The opposite
occurs when interest rates are increased.
Lower interest rates can boost the
prices of assets such as shares and houses. Higher house prices enable existing
home owners to extend their mortgages in order to finance higher consumption.
Higher share prices raise households’ wealth and can increase their willingness
to spend.
Changes in interest rates can also
affect the exchange rate. An unexpected rise in the rate of interest in the UK
relative to overseas would give investors a higher return on UK assets relative
to their foreign-currency equivalents, tending to make sterling assets more
attractive. That should raise the value of sterling, reduce the price of
imports, and reduce demand for UK goods and services abroad. However, the
impact of interest rates on the exchange rate is, unfortunately, seldom that predictable?
Changes in spending feed through into
output and, in turn, into employment. That can affect wage costs by changing
the relative balance of demand and supply for workers. But it also influences
wage bargainers’ expectations of inflation – an important consideration for the
eventual settlement. The impact on output and wages feeds through to producers’
costs and prices, and eventually consumer prices.
Some of these influences can work more
quickly than others. And the overall effect of monetary policy will be more
rapid if it is credible. But, in general, there are time lags before changes in
interest rates affect spending and saving decisions, and longer still before
they affect consumer prices.
We cannot be precise about the size or
timing of all these channels. But the maximum effect on output is estimated to
take up to about one year. And the maximum impact of a change in interest rates
on consumer price inflation takes up to about two years. So interest rates have
to be set based on judgments about what inflation might be – the outlook over
the coming few years – not what it is today.