47-Prefecture Redistricting Simulations

The goal of the 47-Prefecture Simulation Project is to generate and analyze redistricting plans for the single-member districts of the House of Representatives of Japan using a redistricting simulation algorithm. In this project, we use a redistricting simulation algorithm to generate redistricting plans that both limit the number of split municipalities and minimize the voting weight disparity (一票の格差) within each prefecture. Our simulations are designed to comply with the redistricting rules that the Council abides by. We will start with the 19 prefectures subject to redistricting and plan to expand the scope of our research to all 47 prefectures. This repository contains code to sample districting plans for the Japanese House of Representatives for the prefectures subject to redistrict following the demographic shifts reflected in the 2020 Census, according to relevant legal requirements. This dataset contains the sampled plans and accompanying summary statistics.