OPTIMIZATION FOR THE MULTI-MEMBER CONSTITUENCY SYSTEM

Abstract

The focus of this study is to propose the optimization technique to solve the multi-member constituency system, which selects multiple members from a single constituency. In the optimization model, the objective function is to minimize the maximum difference of one vote for the electoral district. In addition, using this technique, we present the optimal division for each parliamentary election of 47 prefectures. As a result, the limit value of the maximum difference of one vote is obtained for each prefecture. Furthermore, based on this result, we can evaluate and analyze the current division of local elections (prefectural assembly elections) which has a large difference compared with the national election (the single-member constituency system in the House of Representatives).