Working Paper: NBER ID: w31442
Authors: Laurent Bouton; Garance Genicot; Micael Castanheira; Allison L. Stashko
Abstract: This paper studies the manipulation of electoral maps by political parties, known as gerrymandering. At the core of our analysis is the recognition that districts must have the same population size but only voters matter for electoral outcomes. We propose a model of gerrymandering that allows for heterogeneity in turnout rates across individuals. We show how this modifies the gerrymandering strategies: the novel pattern is to pack-crack-pack along the turnout dimension. That is, parties benefit from packing their supporters when they have too low turnout rate as well as their opponents when they have too high turnout rate. In between, they create cracked districts that mix moderate-to-high-turnout supporters with lower-turnout opponents. This produces testable empirical implications about the link between partisan support, turnout rates, and electoral maps. Using a novel empirical strategy that relies on the comparison of maps proposed by Democrats and Republicans during the 2020 redistricting cycle in the US, we bring such empirical implications to the data and find support for them.
Keywords: gerrymandering; differential turnout; electoral maps; partisan strategy
JEL Codes: D72
Edges that are evidenced by causal inference methods are in orange, and the rest are in light blue.
| Cause | Effect |
|---|---|
| turnout rates of different voter groups (K16) | strategic decisions made by gerrymanderers (D72) |
| low turnout of supporters (D79) | packing supporters (L87) |
| high turnout of opponents (D72) | packing opponents (L87) |
| turnout rates (K16) | gerrymandering strategies (D72) |
| average turnout rate of individuals in partisan groups (D71) | probability of winning district (C46) |
| higher turnout among opponents (D72) | greater risk to gerrymanderers' electoral success (D72) |