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 analyzed the partisan bias of the 2022 redistricting for 25 prefectures subject to redistricting. Our simulations are designed to comply with the redistricting rules that the Council abides by. This dataset contains sampled districting plans and accompanying summary statistics for the Japanese House of Representatives for the 25 prefectures subject to redistrict following the demographic shifts reflected in the 2020 Census, according to relevant legal requirements.