Abstract
The vote-value disparity becomes the one of essential indices to reform or evaluate the election system. For example, the disparity ratio in the value of one vote in the House of Representatives in Japan is 2.524 in 2010 and has considered an illegal state. Several reform bills are proposed to rectify the disparity. In this paper, I would like to consider the bills from the point of view of the limit of reduction in the disparity ratio. At first, I show the limit of reduction in the disparity ratio is decreased to 2.098 in 2011 from 2.153 in 2006. Furthermore, even if seat allocation formula designed to give disproportionately preferential treatment is reformed, it is 1.898. Another weighty bill to cut a single-seat constituency from five prefectures without increasing seats in other prefectures is not effective because the ratio is 1.931. It is important to numerically recognize disparity risk.
