Roll rates measure how often legislators vote with their party's majority. 📏 Counterfactual Roll Rate Simulation

This study addresses a key challenge in political science: distinguishing genuine partisan agenda control from mere coincidence when observing low roll rates.

We develop counterfactual simulations of what roll rates would look like without actual party influence. By applying these across 87 US legislative bodies (110 congressional sessions and 86 state houses), we test whether observed roll rates genuinely reflect party power or could occur randomly.

📄 Key Findings

Our analysis shows that low roll rates can indeed indicate significant partisan influence in certain contexts, especially when institutional rules grant parties more agenda control. However, this interpretation holds only after accounting for baseline risks of majority-party rolls. 🪫 Implications

This nuanced understanding reshapes how political scientists interpret roll rates as evidence of party power. We demonstrate that the same statistical measure can mean different things depending on institutional context and time period, particularly highlighting findings around 2019's post-Reed's rules House. 📏 Counterfactual Roll Rate Simulation

Our approach provides a clearer methodological path for evaluating partisan agenda control across diverse political institutions.