The Philadelphia Districting Contest: Designing Territories for City Council Based Upon the 2010 Census

Abstract

The City of Philadelphia recently redesigned districts for its council members based upon the 2010 census. The districting process evinced considerable public interest and engagement because council districts from the prior census had significant shortcomings. During the 2010 redistricting process, several public interest groups came together to organize a districting contest. The organizers hoped to increase public engagement in the districting process and to proactively offer several well-constructed examples of city council districts that minimize gerrymandering. We were active participants in the contest, developing methodologies for finding good solutions to large integer programs that enabled us to win in one contest category and make presentations before the city council in this and another category. This article describes the unfolding of various events surrounding the districting process, the methodologies we developed, and the influence that the contest ultimately had on the design of city council districts.

On Empirical Validation of Compactness Measures for Electoral Redistricting and Its Significance for Application of Models in the Social Sciences

“…If an objectively assessable measure of compactness could be agreed upon as the objective in reapportionment, then it would be possible in principle to conduct search and optimization by computer to find good designs. One would minimize the compactness measure (assume smaller is better), subject to legal constraints on contiguity and population size (Cox & Katz, 2002; Kalcsics, Nickel, & Schröder, 2005; Young, 1988; see also Gopalan et al, 2013; Murphy, Hess, & Wong-Martinez, 2012).…”

“…Recent work, undertaken in the context of the design of electoral districts, has led to a promising technique in conjunction with the third option, aimed at making the option more attractive in cases where the proposal can be applied (Chou, Kimbrough, Sullivan, Woodard, & Murphy, 2012; Gopalan, Kimbrough, Murphy, & Quintus, 2013, 2012a). The proposal is designed for cases in which it is problematic to define and parameterize an objective function mathematically; yet, human subjective judgments can distinguish better and worse solutions.…”

Seed-Fill-Shift-Repair: A redistricting heuristic for civic deliberation

“…Bozkaya et al [59,60] applied a search heuristic termed tabu search, which has performed well on many combinatorial problems. Gopalan et al [61] used a restricted set of locations to serve as the centers of districts while using census tracts and their populations to accumulate voters in districts.…”

“…We say that a plan is contiguous if every district in it is contiguous. The contiguity constraint is complex to represent mathematically, although it can be done [61,93]. SFSR uses a computational procedure, described in the sequel, to determine whether the districts in a presented plan are all contiguous.…”

Is Evolutionary Computation Evolving Fast Enough?

“…The gerrymandering problem (the process of manipulating electoral boundaries to gain a political advantage) was addressed in [21]. This was a joint paper between university colleagues and a representative from a government department (Philadelphia Water Department's Office of Watersheds).…”