Japan's electoral reform in 1994 sparked debate about how candidate positioning adapts. This study analyzes ~7,500 election manifestos using quantitative scaling to estimate ideology across eight House of Representatives elections. We find a clear pattern: candidates' positions converge dramatically under single-member districts (SMDs), while diverging significantly within multimember districts (MMDs). When intraparty competition is absent in MMDs, partisan alignment becomes stronger - the opposite effect previously expected from spatial theories.
🔍 Data & Methods
- Analyzed ~7,500 Japanese election manifestos post-reform.
- Used advanced quantitative scaling to measure ideology objectively.
📊 Key Findings
- Candidates move ideologically toward the center in Single-Member Districts.
- They diverge dramatically within Multi-Member Districts (MMDs).
- Without intraparty competition, candidates in MMDs align even more strongly with their partisans.
💡 Why It Matters
This nuanced result clarifies the relationship between electoral systems and Japanese political behavior. The divergence without copartisans challenges conventional spatial theory expectations.
