This study estimates the effect of economic integration between South and North Korea for the Six-Party Talk members including the U.S., China, Japan, and Russia by way of Recursive Dynamic Computable General Equilibrium model.
This study predicts four types of changes from the integration, and utilizes previous studies to estimate the volume of the changes. First, it predicts the change in production factors such as labor, capital, land, and natural resources from the integration. Second, the unification, along with the TPP, would expand the market size. Third, it considers improved finances from reduction of military expense and subsidies from the South to the North. Last, it expects that South-North integration would lead to relaxation of tensions in Northeast Asia and enhancement of trust at the international level, which would affect the Six-Party Talk members positively.
This study considers the following two scenarios: one involving efforts undertaken solely by the South and North, and the other with added effort from the Six-Party Talk members. Additionally this study estimates the minimum and maximum from the four changes and creates detailed scenarios. Those scenarios were applied to the Recurve Dynamic Models, and the economic effects were estimated. According to the estimations, South Korea’s GDP would rise about 1.7~3 percent and North Korea’s GDP would rise about 4.3~110.6 percent solely as a result of the economic integration between the two Koreas. Moreover, the U.S. and Japan’s GDP would rise due to the integration and the TPP, and possibly in some sense China and Russia may experience positive effects as well. In particular, it is predicted that Japan would be the leading beneficiary among the members.  
This study suggests the following implications. First, previous studies estimate the effects in fragmented fashion and thus overlook the fact that each economic agent who is confronted with the changes may lead the new equilibrium. This may result in overestimation of the benefits from the integration. Second, economic growth in North Korea would bring forth considerable benefits to Japan. Third, we may have to pursue a coordinated unification policy in that abrupt economic growth of the North Korea may actually have negative effects on other countries.