Analyzing gender gaps in bicameral legislatures: How asymmetrical institutions affect the supply and demand for female candidates

Abstract In bicameral legislatures, gender representation varies significantly between chambers. Historically, Japan's upper house has maintained a proportion of women twice that of the lower house. However, electoral systems alone cannot fully explain this disparity. We argue that seemingly gender‐neutral legislative institutions influence both voting behavior and candidates' willingness to run, contributing to significant disparities in gender representation in bicameral legislatures. To test this argument, we conduct two survey experiments exploring the underlying mechanisms from the perspectives of voters and candidates. Our findings suggest that informing voters about the upper house's subordinate role increases support for female candidates in upper house elections. Furthermore, women display a greater willingness to pursue office when assured of job security in the upper house, while men exhibit less interest when made aware of its limited authority to appoint the prime minister. This study enhances our current understanding of the effects of asymmetrical institutions between chambers from a gender perspective.