Aggregate Demand Policies
Both fiscal and monetary policy changes shift the AD curve. Let us see how, starting with a fiscal expansion. See figure 6.2. In the upper panel, the initial LM and IS schedules correspond to a given nominal quantity of money and the price level P0. The equilibrium is at point E and there is a corresponding point on the AD schedule in the lower panel. When there is a fiscal expansion, the IS schedule shifts outward and to the right. At the initial price level there is a new equilibrium at point Elwith higher interest rates and higher level of income - and spending. Thus at the initial level of prices, P0, equilibrium income and spending are now higher. This is shown by plotting point El in the lower panel. Point El is a point on the new aggregate demand curve ADl. Doing a similar exercise at other points on the original AD leads us to the derivation of the new aggregate demand curve ADl. We see that the aggregate demand curve has shifted to the right because of fiscal expansion. A fiscal contraction produces the opposite result.
Now, let us study the effect of change in monetary policy on the aggregate demand curve. See figure 6.3. An increase in the nominal stock of money implies a higher real money stock at each level of prices and thus shifts the LM curve to LMl in the upper panel.
The equilibrium level of income rises from Y0 to Yl at the initial price level, P0. Correspondingly, the AD curve moves out to the right, to ADl, with point El in the lower panel corresponding to El in the upper panel. The AD curve shifts up in exactly the same proportion as the increase in the money stock. For instance, at point K the price level, Pl, is higher than P0 in the same proportion that the money supply has increased. Real balances at K and ADl are therefore the same as at E on AD.