Based on imperfect information, use the aggregate demand–aggregate
supply (AD-AS) model to graphically illustrate the difference between demand-pull
and cost-push inflation. Explain your graphs in words.
4. Assume that an economy is initially at the long-run equilibrium, and the
short-run aggregate supply curve is derived from the sticky-price model.
a. Use the AD-AS and Phillips curve diagram to illustrate graphically how the inflation rate
and unemployment rate respond both in the short run and in the long run to an unexpected
expansionary monetary policy.
b. Use the AD-AS and Phillips curve diagram to illustrate graphically how the inflation rate
and unemployment rate respond both in the short run and in the long run to the
announcement of a credible plan of expansionary monetary policy when people have
rational expectations.
