A Partisan Solution to Partisan Gerrymandering: The Define-Combine Procedure
Winner of the Society for Political Methodology Miller Prize for the best work appearing in Political Analysis in 2024
Abstract
Redistricting reformers have proposed many solutions to the problem of partisan gerrymandering, but they all require either bipartisan consensus or the agreement of both parties on the legitimacy of a neutral third party to resolve disputes. In this paper, we propose a new method for drawing district maps, the Define- Combine Procedure, that substantially reduces partisan gerrymandering without requiring a neutral third party or bipartisan agreement. One party defines a map of 2N equal-population contiguous districts. Then the second party combines pairs of contiguous districts to create the final map of N districts. Using realworld geographic and electoral data, we employ simulations and map-drawing algorithms to show that this procedure dramatically reduces the advantage conferred to the party controlling the redistricting process and leads to less-biased maps without requiring cooperation or non-partisan actors.
Coverage & explainers
- The Dangers of America's Gerrymandering Problem—And How to Fix It TIME Ideas · August 14, 2025 By Benjamin Schneer and Maxwell Palmer
- This research could make elections fairer Harvard Kennedy School · April 22, 2024 Video; Benjamin Schneer on gerrymandering and the Define-Combine Procedure
- How politicians can draw fairer election districts the same way parents make kids fairly split a piece of cake The Conversation · February 20, 2024 By Schneer, DeLuca and Palmer
- Cutting the Gerrymandering Cake: "Define-Combine Procedure" Reduces Partisan Bias in District Maps Yale ISPS · January 30, 2024 By Rick Harrison
redistrictingpartisan gerrymanderingrepresentationsimulation methodselectoral reformdivide and choose