5.3 Monetary policy

Monetary policy uses interest rates, money and credit conditions, or the exchange rate to influence aggregate demand and the price level. In many economies the central bank, not the finance ministry, sets the policy instrument.

A lower policy rate can reduce borrowing costs, raise asset prices and weaken the exchange rate, encouraging consumption and investment. The strength and timing depend on confidence, debt, banks and expectations.

If the central bank cuts rates and households refinance cheaper mortgages, disposable income and consumption may rise; if banks are unwilling to lend, the transmission is weaker.

Changing the policy rate does not mechanically change inflation immediately, and monetary policy cannot remove a physical supply shortage.

A central bank can change a policy interest rate, buy or sell assets, alter reserve or liquidity conditions, and use communication or targeted credit measures. The precise toolkit depends on the monetary system.

Open-market purchases can increase bank reserves and lower yields; sales can do the opposite. Forward guidance works through expectations. These tools influence spending only through financial-market and behavioural responses.

Buying government securities may lower longer-term yields and make investment finance cheaper, but the effect is limited if firms lack profitable projects or banks tighten lending standards.

The central bank does not simply “print money into every household account”, and a tool’s intended direction is not guaranteed when confidence or banks’ balance sheets constrain transmission.

An expansionary monetary stance lowers the effective cost of finance or increases liquidity to support demand; a contractionary stance raises financial restraint to reduce inflationary pressure. A neutral stance is consistent with the central bank’s estimate of stable conditions.

The stance is relative to the economy’s needs and neutral rate, not just the level of the policy rate. A low rate may still be contractionary if inflation and the neutral rate are even higher.

A rate rise from 2% to 3% may be contractionary during weak demand, but expansionary in a high-inflation economy if it remains below the rate needed to slow spending.

“High” and “low” are not enough to classify policy; compare the instrument with inflation, expectations, output and the neutral benchmark.

A change in monetary policy can shift aggregate demand by changing consumption, investment, net exports and sometimes asset prices. The direction is clearer than the size of the effect.

Lower interest rates usually reduce the cost of borrowing and the reward for saving, may raise asset values, and can weaken the exchange rate. Higher rates generally work in reverse. Banks, confidence, debt and the trade response determine the transmission.

A rate cut may increase mortgage disposable income and investment, shifting AD right. If the economy is near capacity, the main result may be a higher price level rather than much extra real output.

The AD shift is not the same size in every economy, and monetary expansion cannot instantly shift productive capacity or cure a supply shock.