Original
Redistricting Reforms Reduce Gerrymandering by Constraining Partisan Actors
Abstract
Political actors often manipulate redistricting plans to gain electoral advantages, a process known as gerrymandering. Several states have implemented institutional reforms to address this problem, such as establishing map-drawing commissions. Estimating the impact of these reforms is challenging because each state structures its processes and rules differently. We model redistricting as a sequential game whose equilibrium solution summarizes multistep institutional interactions as a univariate score. We argue that this score measures the leeway political actors have over the partisan lean of the final plan. Our differences-in-differences analysis demonstrates that reforms reduce partisan bias and increase competitiveness by constraining partisan actors. We perform a counterfactual policy analysis to estimate the effects of enacting recent reforms nationwide. Though commissions are likely to reduce bias, reforms that restrict partisan actors in multiple ways, such as removing veto points (Michigan), are more effective than commissions where parties retain some control (Ohio).
中文
选区重划改革通过约束党派行为者减少不公正划分选区
摘要
政治行为者常常操纵选区重划方案以获取选举优势，这一过程被称为不公正划分选区（杰利蝾螈）。若干州已实施制度改革以应对这一问题，例如设立地图绘制委员会。估算这些改革的影响颇具挑战，因为各州对其程序和规则的架构各不相同。我们将选区重划建模为一个序贯博弈，其均衡解将多步骤制度互动概括为一个单变量得分。我们认为，该得分衡量了政治行为者对最终方案党派倾向的回旋空间。我们的双重差分分析表明，改革通过约束党派行为者降低了党派偏见并提高了竞争性。我们进行反事实政策分析，以估计在全国范围内实施近期改革的效果。尽管委员会很可能减少偏见，但以多种方式限制党派行为者的改革——例如取消否决点（密歇根州）——比政党仍保留部分控制的委员会（俄亥俄州）更为有效。
关键词
选区重划、杰利蝾螈、选举改革、党派偏见、竞争性、制度约束、双重差分、反事实分析