“Doshusei” is one of the most drastic reforms in the Japanese domestic public system so far. In the midst of the arguments, the experiment of “Doshusei” has just started including of a political intention in Hokkaido since 2004. We tried to focus our research under situations such as the development of new political movements. Furthermore, our study applies the theory of Interregional Payment Balances (IPB) to an actual regional economy (Doshusei). From this application study of IPB, it was possible to make suggestions for the regional economic policies, especially, in the following three areas. 1. The deficit in IPB has been formed when the imports of a region are higher than the exports. It is said that it is to increase the regional income per capita partially. However, it is not true in the region economically. The deficit in the IPB has been usually made up by the central government as a “gift.” From this it can be seen that regional economy lacks a self support system. Certainly the deficit in the IPB is evidence of a weakness of economic power in Japanese regions. The intention of this paper tried to far clarify than the former researches. 2. Profit in a regional economy is brought about more by the amount of consumption in the region than the amount of imports. This conclusion, of course, does not always mean that a closed economy is better than an open economy, but it is true that an open economy (seldom the orientation of an extreme open market) is not profitable for the region. 3. IPB depends on the scale of inclination of marginal consumption and marginal import. These two curves show different slopes. The former curve is related to net savings and the latter to net trade. Both slopes are not completely fixed but actually variable. These two curves (innumerable) always hold the same points of equilibrium in relation to each other. An important finding is that there are innumerable points of the same equilibrium. In this sense, IPB fits within the theory of general equilibrium. It is possible to escape from the so-called simultaneous dilemma of interregional unbalance through this analysis. As above, we have been tried to the evidence some issues through a research of an economic model of Doshusei. We set up the several forecast numbers. It shows examples of an advanced study of IPB.

JEL classification : R₁₁, R₁₃