A change in the expected rate of inflation

A natural disaster which temporarily disrupts production

Improved technology which increases labour demand

A rise in the price of imported inputs

To secure generally stable prices, governments should aim to keep the money stock stable over time

Government efforts to reduce unemployment have lags, so when they take effect, it may be too late

Government efforts to hold unemployment below the natural rate will lead to accelerating inflation if people form adaptive expectations about the inflation rate

If the unemployment rate exceeds the natural rate, wage flexibility will return the rate to the natural rate quite quickly.

They assume that people take account of all information

They assume that, on average, people’s forecasts are correct

They imply that expected changes in demand have no effects on unemployment or the price level

They imply that unexpected changes in demand have long-lasting effects on both unemployment and the price level

Efficiency wages may hold wages below the equilibrium level.

Workers may resist wage cuts which reduce their wages below those paid to other workers in the same occupation

Prices may be sticky downwards in some markets because consumers prefer stable prices

Prices may be sticky downwards in some markets because consumers may judge quality by price

The central bank will make its interest rate decisions solely by considering whether actual inflation goes above or below the target

The central bank will decrease the interest rate if there is a demand shock which reduces aggregate demand

The central bank will increase the interest rate if there is a supply shock which permanently reduces aggregate supply

The central bank may not increase the interest rate if there is a supply shock which temporarily reduces aggregate supply