Since the currency crisis in 1998, Korea has experienced continuous current account surpluses. Recently, the current account surplus increased more rapidly—amounting to 7.7 percent of GDP in 2015. In this paper, we investigate the underlying reasons for the widening of Korea's current account surpluses. We find that the upward trend in Korea's current account surpluses is largely explained by its demographical changes. Other economic variables are only helpful when explaining short run fluctuations in current account balances. Moreover, we show that Korea's current account surplus is expected to disappear by 2042 as it becomes one of the most aged economies in the world. Demographic changes are so powerful that they explain, quite successfully, the current account balance trends of other economies with highly aged populations such as Japan, Germany, Italy, Finland, and Greece. When we add the real exchange rate as an additional explanatory variable, it is statistically significant with the right sign, but the magnitude explained by it is quite limited. For example, to reduce the current account surplus by 1 percentage point, a 12 percent depreciation is needed. If Korea's current exchange rate is undervalued 4 to 12 percent less than the level consistent with fundamentals, it is impossible to reduce Korea's current account surplus to a reasonable level by adjusting the exchange rate alone. Another way to reduce current account surplus is to expand fiscal policies. We find, however, that the impact of fiscal adjustments in reducing current account surplus is even more limited. According to our estimates, reducing the current account surplus by 1 percentage point requires an increase in budget deficits (as a ratio to GDP) of 5 to 6 percentage points. If we allow endogenous movements of exchange rate and fiscal policy, the impact of exchange rate adjustment increases by 1.6 times but that of fiscal policy decreases that it is no longer statistically significant.
The Role of the Current Account in Exchange Rate Determination : A Comment on Rodriguez