British MPs don't always follow party lines, even when ideology points toward strong discipline.
➡️ Data & Methods
- Original dataset of MP votes and speeches (1992-2015).
- New estimations of MPs' ideological positions within their party.
🔍 Key Findings
- Ideological extremity interacts with government control to trigger rebellion.
- Extremists are loyal in opposition but rebel more when their party governs.
- Rebel MPs emphasize their votes through speeches ('grandstanding').
🧬 Why It Matters
- Existing models of party discipline don't account for this pattern.
- Rebellion strategy depends on both the MP's position within the party and whether that party is governing or in opposition.
