1997년 외환위기 이후부터 한국은 지속적으로 경상수지 흑자를 이어 왔으며, 최근 급속히 증가하여 2015년에는 경상수지 흑자 규모가 GDP의 7.7%에 이르고 있다. 본 논문은 한국이 이토록 큰 규모의 경상수지 흑자를 경험하고 있는 이유를 OECD 국가의 자료를 사용하여 분석하였다. 본 논문의 분석결과에 따르면 한국의 경상수지가 최근에 증가하는 이유는 한국이 겪고 있는 인구구조의 변화에 주로 기인한다. 고령화가 많이 진행되고 있는 다른 OECD 국가들의 경우에도 인구구조의 변화는 이들 국가의 경상수지 변화가 장기적으로 변화하는 모습을 대체로 잘 설명한다. 한국의 경상수지는 장차 인구구조의 변화를 반영하여 2042년에는 0으로 줄어 들고 그 후에는 경상수지가 적자로 전화될 것으로 예상되었다. 한국은 경상수지 흑자를 줄이기 위하여 환율을 조정하거나 정부재정을 확대하도록 권고받고 있는데 이러한 정책의 효과는 그리 크지 않은 것으로 분석되었다. 예를 들어 1%의 경상수지를 줄이기 위해 환율은 12%의 절상이 필요하며, 정부재정은 GDP 대비 5-6%의 적자재정이 필요하다. 이러한 수치는 환율 및 재정정책의 내생성을 고려하지 않는 수치이며, 이들 변수들의 내생성을 고려한 경우 환율이 경상수지에 미치는 직접적인 효과는 1.6배 늘어나는 데 그치고 재정정책의 효과는 오히려 감소하는 것으로 분석되었다.
핵심용어: 경상수지, 인구구조, 고령화
In this paper, we present an empirical methodology that explains how current account balances are determined and by employing it, try to diagnose factors that account for Korea's current account surplus. In fact, the IMF has introduced a methodology, the External Balance Assessment (EBA: Phillips et al., 2013), to assess exchange rate and current account gaps that are defined as the difference between current levels and those consistent with fundamentals. For example, the 2016 External Sector Report, by utilizing this methodology, demonstrates that Korea's real effective exchange rate in 2015 was 4 to 12 percent undervalued than the level consistent with fundamentals.
While the IMF's EBA is a state-of-the-art methodology that incorporates major studies in the literature, we feel that it has some limitations when analyzing the movements of Korea's current account balances. The method implicitly assumes that the current account surpluses of these countries will be substantially reduced by changing the exchange rate. However, the current account surpluses of Korea cannot be explained by the exchange rate alone. After the global financial crisis, despite rapid appreciation of the real effective exchange rate, Korea's current account surplus has been continuously increasing.
Korea experienced a currency crisis in 1998. Since then it has experienced continuous current account surpluses. The current account surpluses just after the crisis were extremely helpful for the economy to recover from the crisis. Managing a modest level of current account surpluses has also been beneficial for the economy in preventing future crises. However, Korea's current account surplus in 2015 amounted to 7.7% of GDP, causing a concern that it may be too excessive. This exorbitant reliance on external demand can esca-late political pressures from trading partners to appreciate the exchange rate. It is also argued that maintaining more balanced demand sources by giving domestic demand a greater role is essential for a sustained growth path.
In this paper, we investigated underlying reasons as to why Korea's current account surpluses are widening. We found that the upward trend in Korea's current account surpluses is essentially explained by demographical changes it is currently experiencing. Moreover, we show that since Korea's population is rapidly aging, its current account surplus is expected to disappear by 2042 as it becomes one of the most aged economies in the world. In fact, demographical changes are so powerful that they explain quite successfully the trend of current account balances of other aged economies such as Japan, Germany, Italy, Finland and Greece as well. However, demographics do not explain cross-country differences in the level of current account balances, i.e. the high level of Korea's current account surpluses is mainly explained by a country fixed effect.
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, in order to reduce current account surplus by 1 percentage point, a whopping 12% depreciation is needed. Since other economic variables are yet included as explanatory variables, this can be considered to be the maximum estimate of the effect of the exchange rate changes. If it is true that Korea's current exchange rate is 4 to 12 percent undervalued 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 possibility to reduce current account surplus is expanding fiscal policies. We find, however, that the impact of fiscal adjustments on current account surplus is even more limited. According to our estimates, reducing current account surplus by 1 percentage point requires a 5-6 percentage points increase in budget deficits (as a ratio to GDP).
The above impacts of exchange rate and fiscal policy adjustments are estimated without considering the endogeneity of these policy variables. If we allow endogenous movements of these variables, the impact of exchange rate adjustment is 1.6 times larger, while that of fiscal policy decreases so that it is no longer statistically significant.
When we add other economically fundamental variables such as GDP gap, oil prices, net foreign asset and so on, they contribute to explaining short run fluctuations without much improvement in explaining the trend nor country fixed effects. On the other hand, while the upward trend in Korea's current account surplus since 1997 is mainly explained by demographical changes, the current level of current account surplus, i.e. 7.7% of GDP, is placed quite above the fitted line derived by the economically fundamental variables including demographical changes.
This idiosyncrasy of Korea's current account surplus seems to be related to increasing saving propensity of households especially among aged people. However, we will need further detailed analyses for more rigorous evidence to support this argument.
2. Korea and Global Imbalances
3. Data and Methodology
4. Decomposition of Korea’s Current Account Surplus
5. Policy Implications