An official website of the United States government
Gerrymandering is the manipulation of redistricting to influence the results of a set of elections for local representatives. Gerrymandering has the potential to drastically swing power in legislative bodies even with no change in a population’s political views. Identifying gerrymandering and measuring fairness using metrics of proposed district plans is a topic of current research, but there is less work on how such plans will be perceived by voters. Gathering data on such perceptions presents several challenges such as the ambiguous definitions of ‘fair’ and the complexity of real world geography and district plans. We present a dataset collected from an online crowdsourcing platform on a survey asking respondents to mark which of two maps of equal population distribution but different districts appear more ‘fair’ and the reasoning for their decision. We performed preliminary analysis on this data and identified which of several commonly suggested metrics are most predictive of the responses. We found that the maximum perimeter of any district was the most predictive metric, especially with participants who reported that they made their decision based on the shape of the districts.
more »
« less
The impact of highly compact algorithmic redistricting on the rural-versus-urban balance
It is commonly believed that, in congressional and state legislature elections in the United States, rural voters have an inherent political advantage over urban voters. We study this hypothesis using an idealized redistricting method, balanced centroidal power diagrams, that achieves essentially perfect population balance while optimizing a principled measure of compactness. We find that, using this method, the degree to which rural or urban voters have a political advantage depends on the number of districts and the population density of urban areas. Moreover, we find that the political advantage in any case tends to be dramatically less than that afforded by district plans used in the real world, including district plans drawn by presumably neutral parties such as the courts. One possible explanation is suggested by the following discovery: modifying centroidal power diagrams to prefer placing boundaries along city boundaries significantly increases the advantage rural voters have over urban voters.
more »
« less
- Award ID(s):
- 1841954
- PAR ID:
- 10217105
- Date Published:
- Journal Name:
- Proceedings of the 28th International Conference on Advances in Geographic Information Systems
- Page Range / eLocation ID:
- 397 to 400
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
More Like this
-
-
Abstract Political conflicts about energy and climate change policies often have local implications, yet little is known about local public opinion towards these policies. Here, we estimate support towards 26 climate change mitigation policies for 402 German counties and for up to four points of time using multilevel regression and poststratification. We find that local support for climate policies varies by up to 60 percentage points across German counties with large disparities between the rural and urban population. While support for the expansion of wind power plants and solar power plants have converged over the last years, attitudes on the phase-out of coal power have polarized across regions. Using a spatial panel analysis, we find that support for the expansion of wind and solar plants correlate with the actual development of solar and wind capacities in these regions. Moreover, the spread of climate policy opinion is strongly determined by spatial diffusion as change in one region positively influences the trajectory of policy opinion among its neighbors.more » « less
-
We consider the problem of political redistricting: given the locations of people in a geographical area (e.g. a US state), the goal is to decompose the area into subareas, called districts, so that the populations of the districts are as close as possible and the districts are ``compact'' and ``contiguous,'' to use the terms referred to in most US state constitutions and/or US Supreme Court rulings. We study a method that outputs a solution in which each district is the intersection of a convex polygon with the geographical area. The average number of sides per polygon is less than six. The polygons tend to be quite compact. Every two districts differ in population by at most one (so we call the solution balanced). In fact, the solution is a centroidal power diagram: each polygon has an associated center in ℝ³ such that * the projection of the center onto the plane z = 0 is the centroid of the locations of people assigned to the polygon, and * for each person assigned to that polygon, the polygon's center is closest among all centers. The polygons are convex because they are the intersections of 3D Voronoi cells with the plane. The solution is, in a well-defined sense, a locally optimal solution to the problem of choosing centers in the plane and choosing an assignment of people to those 2-d centers so as to minimize the sum of squared distances subject to the assignment being balanced. * A practical problem with this approach is that, in real-world redistricting, exact locations of people are unknown. Instead, the input consists of polygons (census blocks) and associated populations. A real redistricting must not split census blocks. We therefore propose a second phase that perturbs the solution slightly so it does not split census blocks. In our experiments, the second phase achieves this while preserving perfect population balance. The district polygons are no longer convex at the fine scale because their boundaries must follow the boundaries of census blocks, but at a coarse scale they preserve the shape of the original polygons.more » « less
-
Debates over racial voting, and over policies to combat vote dilution, turn on the extent to which groups’ voting preferences differ and vary across geography. We present the first study of racial voting patterns in every congressional district (CD) in the United States. Using large-sample surveys combined with aggregate demographic and election data, we find that national-level differences across racial groups explain 60% of the variation in district-level voting patterns, whereas geography explains 30%. Black voters consistently choose Democratic candidates across districts, whereas Hispanic and white voters’ preferences vary considerably across geography. Districts with the highest racial polarization are concentrated in the parts of the South and Midwest. Importantly, multiracial coalitions have become the norm: in most CDs, the winning majority requires support from non-white voters. In arriving at these conclusions, we make methodological innovations that improve the precision and accuracy when modeling sparse survey data.more » « less
-
null (Ed.)The congressional incumbency advantage reflects an inequity in competition—candidates receive an electoral edge simply because they hold office. Scholars have identified an array of factors that contribute to the incumbency advantage; however, the role of electoral campaigns has been largely ignored. We argue that campaigns are a mechanism through which the incumbency advantage works. All else constant, incumbents focus their campaigns on factors that reflect their standing position, such as their familiarity to voters and actions taken for their district/state. Voters consequently rely on such incumbency factors when making their decisions. The outcome is challengers are at an extreme disadvantage, and campaigns offer scant substantive engagement. We offer evidence for these dynamics with a large-scale content analysis of campaign websites and an experiment. In so doing, we highlight a challenge to theories of democratic representation that focus on equal competition and/or substantive campaign engagement.more » « less
- Free Publicly Accessible Full Text
-
Accepted Manuscript1.0
- Conference Paper:
- https://doi.org/10.1145/3397536.3422249
