Assignment 4 goanho jeon 7722139

1. a) An increase in the money supply shifts the LM curve to the right in the short run. This moves the economy from point A to point B in the figure: the interest rate falls from r1 to r2, and output rises from Y to Y2. The increase in output occurs because the lower interest rate stimulates investment, which increases output. Since the level of output is now above its long-run level, prices begin to rise. A rising price level lowers real balances, which raises the interest rate. As indicated in the figure, the LM curve shifts back to the left. Prices continue to rise until the economy returns to its original position at point A. The interest rate returns to r1, and investment returns to its original level. Thus, in the long run, there is no impact on real variables from an increase in the money supply

b) An increase in government purchases. An increase in government purchases shifts the IS curve to the right, and the economy moves from point A to point B, as shown in the figure below. In the short run, output increases from Y to Y2, and the interest rate increases from r1 to r2. The increase in the interest rate reduces investment and “crowds out” part of the expansionary effect of the increase in government purchases. Initially, the LM curve is not affected because government spending does not enter the LM equation. After the increase, output is above its long-run equilibrium level, so prices begin to rise. The rise in prices reduces real balances, which shifts the LM curve to the left. The interest rate rises even more than in the short run. This process continues until the long-run level of output is again reached. At the new equilibrium, point C, interest rates have risen to r3, and