Suchergebnisse

Intro -- Contents -- Preface -- Introduction -- How (not) to spot a gerrymander -- The universe of possibilities -- Theory meets practice -- Adding things up -- Conclusion: What's next? -- Explainer: Compactness, by the numbers -- I Political thought -- Measuring partisan fairness -- Proportionality -- Partisan symmetry -- The efficiency gap -- Ensembles and outliers -- Conclusion: Debating fairness -- Interviews: Concepts of representation -- Redistricting: Math, systems, or people? -- Introduction -- A people problem -- A systems problem -- A math problem -- A systems problem, v.2 -- A people problem, v.2 -- Political geography and representation -- Introduction -- Urban geography and partisan tilt -- Sampling at different scales -- Seats-votes plots -- East versus West -- Conclusion -- II Law -- Explainer: A brief introduction to the VRA -- Race and redistricting -- Introduction -- Into the thicket: The constitutional framework -- Elaboration: The statutory framework -- Uneasiness: Recasting frameworks in the 1990s -- Hostility: Race, redistricting, and the Roberts Court -- Conclusion: Future of the VRA -- Law, computing and redistricting in the 1960s -- Against computers -- The apportionment revolution meets the computer revolution -- The widening gap between equality and fairness -- The law of gerrymandering -- Backdrop -- Partisan vs. racial gerrymandering -- Constitutional provisions regulating partisanship -- Alternative approaches -- A call to action -- III Geography -- Race, space, and the geography of representation -- Introduction -- Population distribution: cause and effect -- Geography on multiple scales -- Concluding thoughts: Pay attention to race -- The elusive geography of communities -- Community as a principle of representation -- Are communities places or not? -- The functional logic of regional definition.

Abstract
American democracy is currently heavily reliant on plurality in single-member districts, or PSMD, as a system of election. But public perceptions of fairness are often keyed to partisan proportionality, or the degree of congruence between each party's share of the vote and its share of representation. PSMD has not tended to secure proportional outcomes historically, partially due to gerrymandering, where line-drawers intentionally extract more advantage for their side. But it is now increasingly clear that even blind PSMD is frequently disproportional, and in unpredictable ways that depend on local political geography. In this paper we consider whether it is feasible to bring PSMD into alignment with a proportionality norm by targeting proportional outcomes in the design and selection of districts. We do this mainly through a close examination of the "Freedom to Vote Test," a redistricting reform proposed in draft legislation in 2021. We find that applying the test with a proportionality target makes for sound policy: it performs well in legal battleground states and has a workable exception to handle edge cases where proportionality is out of reach.

© 2020 The Author(s). Published with license by Taylor and Francis Group, LLC. The recent wave of attention to partisan gerrymandering has come with a push to refine or replace the laws that govern political redistricting around the country. A common element in several states' reform efforts has been the inclusion of competitiveness metrics, or scores that evaluate a districting plan based on the extent to which district-level outcomes are in play or are likely to be closely contested. In this article, we examine several classes of competitiveness metrics motivated by recent reform proposals and then evaluate their potential outcomes across large ensembles of districting plans at the Congressional and state Senate levels. This is part of a growing literature using MCMC techniques from applied statistics to situate plans and criteria in the context of valid redistricting alternatives. Our empirical analysis focuses on five states—Utah, Georgia, Wisconsin, Virginia, and Massachusetts—chosen to represent a range of partisan attributes. We highlight situation-specific difficulties in creating good competitiveness metrics and show that optimizing competitiveness can produce unintended consequences on other partisan metrics. These results demonstrate the importance of (1) avoiding writing detailed metric constraints into long-lasting constitutional reform and (2) carrying out careful mathematical modeling on real geo-electoral data in each redistricting cycle.

AbstractWe consider the measures of partisan symmetry proposed for practical use in the political science literature, as clarified and developed in Katz, King, and Rosenblatt (2020, American Political Science Review 114, 164–178). Elementary mathematical manipulation shows the symmetry metrics to have surprising properties that call their meaningfulness into question. To accompany the general analysis, we study measures of partisan symmetry with respect to recent voting patterns in Utah, Texas, and North Carolina, flagging problems in each case. Taken together, these observations should raise major concerns about the available techniques for quantitative scores of partisan symmetry—including the mean–median score, the partisan bias score, and the more general "partisan symmetry standard"—with the decennial redistricting underway.