[8 marks]
In its initial depreciation after a money supply rise, the exchange rate jumps from E 1 up$/€ to E 2 , a depreciation greater than its long-run depreciation from E 1 to E 3. The exchange rate is said to overshoot when its immediate response to a disturbance is greater than its long-run response. Exchange rate overshooting is an important phenomenon because it helps explain why exchange rates move so sharply from day to day. The economic explanation of overshooting comes from the interest parity condition.
Question 4 (a) Using the AA/DD framework, explain the separate effects of a temporary monetary expansion and a temporary fiscal expansion on the exchange rate, output and the current account. [10 marks]
Effects of a Temporary Increase in the Money Supply
An increased money supply shifts AA1 upward to AA2 but does not affect the position of DD. The upward shift of the asset market equilibrium schedule moves the economy from point 1, with exchange rate E 1 and output Y 1, to point 2, with exchange rate E 2 and output Y 2. An increase in the money supply causes a depreciation of the domestic currency, an expansion of output, and therefore an increase in employment.
At the initial output level Y 1 and given the fixed price level, an increase in money supply must push down the home interest rate, R. We have been assuming that the monetary change is temporary and does not affect the expected future exchange rate, E e, so to preserve interest parity in the face of a decline in R (given that the foreign interest rate, R*, does not change), the exchange rate must depreciate immediately to create the expectation that the home currency will appreciate in the future at a faster rate than was expected before R fell. The immediate depreciation of the domestic currency, however, makes home products cheaper relative to foreign products. There is therefore an increase in