Redistricting and Technology
This talk, presented as guest lecture in Ron Rivest’s and Charles Stewart’s class on Elections and Technology, reflects on the use of technology in redistricting, and lessons learned about open data, public participation, technology, and data management from conducting crowd-sourced election mapping efforts.
- On technical implementation: There is still a substantial gap between the models and methods used in technology stack, and that used in mapping and elections. The domain of electoral geography deals with census, and administrative units; legally defined relationships among units; randomized interventions — where GIS deals with polygons, layers, and geospatial relationships. These concept often maps — with some exceptions — and in political geography, one can run into a lot of problems if one doesn’t pay attention to the exceptions. For example, spatial contiguity is often the same as legal contiguity, but not always — and implementing the “not always” part implies a whole set of separate data structures, algorithms, and interfaces.
- On policy & transparency: We often assume that transparency is satisfied by making the rules (the algorithm) clear, and the inputs to the rules (the data) publicly available. In election technology, however, code matters too — its impossible to verify or correct implementation of an algorithm without the code; and the form of the data matters — transparent data containing complete information, in accessible formats, available through a standard API, accompanied by documentation, and evidence of authenticity.
- On policy & participation: Redistricting plans are a form of policy proposal. Technology is necessary to enable of richer participation in redistricting — it enables individuals to make complete, coherent alternative proposals to those offered by the legislature. Technology is not sufficient, although the courts sometimes pay attention to these publicly submitted maps, legislatures have strong incentives to act in self-interested ways. Institutional changes are needed before fully participative redistricting becomes a reality.
- On policy implementation: engagement with existing grass-roots organizations and the media was critical for participation. Don’t assume that if you build it, anyone will come…
- On methodology: Crowd-sourcing enables us to sample from plans that are discoverable by humans — this is really useful as unbiased random-sampling of legal redistricting plans is not feasible. By crowd-sourcing large sets of plans we can examine the achievable trade-offs among redistricting criteria, and conduct a “revealed preference” analysis to determine legislative intent.
- Ad-hoc, miscellaneous, preliminary observations: Field experiments in this area are hard — there are a lot of moving parts to manage — creating the state of the practice, while meeting the timeline of politics, while working to keep the methodology (etc.) clean enough to analyze later. And always remember Kransberg’s 1rst law: technology is neither good nor bad — neither is it neutral.
We’ve also written quite a few articles, book chapters, etc. on the topic that expand on many of these topics.