164 – 164 - Social Statistics Speed Session
Investigating Similarities and Differences Across States in DVC Scores for Evaluating Redistricting Plans
Thomas R. Belin
University of California, Los Angeles
There has been widespread concern about gerrymandering in the redistricting process, but applicable laws still leave room for partisan manipulation of redistricting. Viewing redistricting from a public official's perspective, avoiding reliance on data other than from the census, Belin, Fischer, and Zigler (2011 Statistics, Politics and Policy) introduced the idea of a “density-variation / compactness� (DVC) score as a one-number summary where plans with higher scores can be expected to have fewer “safe seats�. Drawing on expanded accessibility of mapping software, we carried out analyses of the originally proposed DVC score, with an eye toward identifying similarities and differences in values across states. In particular, we were interested to investigate unusual values, which we noted arose in cases where there was a change in the apportionment of congressional seats to a state that led to consequences for district-specific population densities. We discuss the implications of these findings for the utility of the DVC score as an accessible measure that can be reported rapidly to facilitate public consideration of the merits of redistricting plans before plans are finalized.