1 and 3 only

1 and 4 only

2 and 3 only

2 and 4 only

Phillips’s original curve concerned increases in nominal wages, not increases in the price level

Phillips’s observations suggested that his curve was generally stable between 1861 and 1957

Phillips curves are generally concerned with increases in the price level, not increases in nominal wages

Phillips curves have generally been fairly stable since 1957

0%

Between 0% and 5%

5%

Over 5%

Because in the long run, government policies will ensure that unemployment is at its natural rate.

Because in the long run, the labour market will settle so that unemployment is at its natural rate

Because of the quantity theory of money

Because its true shape is unknown

rise in the expected rate of inflation

A natural disaster which temporarily disrupts production

A rise in the benefits paid to unemployed people.

An increase in the labour force