Estimating Interregional Trade by the Gravity-RAS Method

In creating an intra-regional IOT of one prefecture, estimating the trade among regions is important, one of which, the gravity-RAS method, is examined by applying Aichi prefecture as a case. The interregional trade data within a country continues to be difficult to obtain completely, which forces one to shift from adopting the survey method to some kind of non-survey method in the estimation of the interregional trade coefficients. LQ techniques, gravity models, the RAS method, and others have been developed or applied for such estimation. In this chapter, we summarize related preceding research and explain the gravity-RAS method, a method of estimating interregional trade that is considered here. We estimate the model and examine the degree of difference in the IOT of Aichi Prefecture depending on the given conditions.