Unayama (2002) points out that the regional price index used in "National Survey of Prices" has an inconsistent property, which he calls "average value incoherency." To cope with this difficulty, he proposes a new index. Here, I propose another formula that is close to the current index formula and at the same time that can avoid the incoherency. Thus, the proposed index is easier to understand, and since it is closer to the current formula, it may be more comparable with previous survey results.
