Estimating the Causal Effects of Institutional Constraints on Redistricting

• In Event: Redistricting and Representation

Abstract

In redistricting, map drawers are tasked with balancing many competing priorities, from drawing legally compliant plans to manipulating the partisanship of districts. Many plans end up in court, while others are passed along partisan lines with little fanfare. Despite the consequences of these processes for representative democracy in America, little is known about how each state's institutions affect the plans drawn. We first provide a formal model of institutional leeway, where we estimate the degree to which legal constraints, partisan control of institutions, and levels of review allow map drawers to impart bias into congressional maps. We then provide some of the first causal evidence of how institutional leeway directly leads to biases in redistricting maps, using a continuous differences-in-differences-in-differences approach. Identification comes from the difference over time. We then difference out "unintentional" biases imparted from rules and geography by using representative samples of simulated redistricting plans.

Authors

• Cory McCartan, Harvard University

• Emma Ebowe, Harvard University

• Christopher Kenny, Harvard University

• Tyler Simko, Harvard University

• Michael Zhao, Harvard University

• Kosuke Imai, Harvard University