Evaluating districting plans in the real world

GerryChain is used to analyze redistricting plans in the real world. For example, it’s been used in states ranging from Pennsylvania to North Carolina to Wisconsin for defend civil rights. So, MGGG has developed a toolkit of functions for use to analyze a redistricting plan. Here, we will describe these tools and how they are used to analyze real-world districting plans.

gerrytools

gerrytools is a toolkit that contains:

  • a suite of plan scoring metrics (like efficiency gap and reock scores) for use in comparing plans

  • a suite of data grabbing/manipulating tools, with an emphasis on interacting with Census data

  • super-easy and beautiful visualization functions to make pretty graphs and intuitive displays of data

  • miscellaneous things we find useful

It also has fairly good documentation, which you can read here: https://mggg.github.io/gerrytools/

PyEI

PyEI is a ecological inference package in Python that is intended for racial polarized voting analysis. This analysis is required for Voting Rights Act challenges of gerrymandered redistricting maps. As such, PyEI is essential to MGGG’s work.

Other tools

There are also other tools maintained by MGGG, including maup and pcompress, which have their own set of documentation.