2024 Theses Bachelor's

The Impact of Redistricting Commission Design on Partisan Fairness Performance

Luce, Daniel

This study evaluates the performance of independent redistricting commissions (IRCs) on various measures of partisan fairness using the Sequential Monte Carlo simulation method. It also evaluates the impact of institutional design features on partisan fairness by clustering IRCs into two categories based on these features. The findings suggest that IRCs as a whole outperform legislative redistricting on partisan-aware symmetric fairness metrics like the mean-median difference but are less consistent on partisan-aware proportionality metrics and partisan-blind metrics. However, IRC performance does appear to vary based on design criteria. “Type II” IRCs with balanced partisan composition, more unaffiliated commissioners, explicit considerations of partisanship, and non-majoritarian approval mechanisms consistently outperformed legislative redistricting and "Type I" IRCs that lacked such safeguards on partisan-aware mean-median fairness and potentially the partisan-aware efficiency gap. However, Type I IRCs outperformed legislative redistricting and Type II IRCs on the partisan-blind mean-median metric.

Keywords: redistricting, partisan fairness, institutional design, redistricting commissions