Consider the economy of Hicksonia

a. The consumption function is given by

C = 200 + 0:75(YT )

and the investment function is

I = 20025r:

Government purchases and taxes are both 100. For this economy, graph the IS curve for r ranging

from 0 to 8.

b. The money demand function in Hicksonia is

M

P

d

= Y100r:

The money supply M is 1,000 and the price level P is 2. For this economy, graph the LM curve for r

ranging from 0 to 8. Find the equilibrium interest rate r and the equilibrium level of income Y .

c. Suppose that government purchases are raised from 100 to 150. How does the IS curve shift? What

are the new equilibrium interest rate and level of income?

d. Suppose instead that the money supply is raised from 1,000 to 1,200. How does the LM curve shift?

What are the new equilibrium interest rate and level of income?

e. With the initial values for monetary and scal policy, suppose that the price level rises from 2 to 4.

What happens? What are the new equilibrium interest rate and level of income?

f Derive and graph an equation for the aggregate demand curve. What happens to this aggregate demand

curve if scal or monetary policy changes, as in parts (c) and (d)?