As described above, the adjacency graph was modified by hand to reflect Washington's contiguity requirements. The full list of these changes can be found in the '01_prep_WA_cd_2010.R' file.
Simulation Notes
We sample 13,000 districting plans for Washington using the SMC algorithm and thinned the samples down to 5,000. To comply with the federal VRA and to respect communities of interest, we add a weak VRA constraint targeting one majority-minority district (currently WA-09).
To balance county and municipality splits, we create pseudocounties for use in the county constraint, which leads to fewer municipality splits than using a county constraint. Note that King County, Pierce County, and Snohomish County must all be split due to their large populations, although within the counties, we avoid splitting any municipality.
2010 Washington Congressional Districts
Redistricting requirements
In Washington, districts must according to HCR 4409 (https://apps.leg.wa.gov/billsummary/?BillNumber=4409&Year=2011&Initiative=false):
Interpretation of requirements
We enforce a maximum population deviation of 0.5%. We also used ferry routes in order to create districts linking precincts that are offshore.
Data Sources
Data for Washington comes from the ALARM Project's 2020 Redistricting Data Files.
Pre-processing Notes
As described above, the adjacency graph was modified by hand to reflect Washington's contiguity requirements. The full list of these changes can be found in the '01_prep_WA_cd_2010.R' file.
Simulation Notes
We sample 13,000 districting plans for Washington using the SMC algorithm and thinned the samples down to 5,000. To comply with the federal VRA and to respect communities of interest, we add a weak VRA constraint targeting one majority-minority district (currently WA-09). To balance county and municipality splits, we create pseudocounties for use in the county constraint, which leads to fewer municipality splits than using a county constraint. Note that King County, Pierce County, and Snohomish County must all be split due to their large populations, although within the counties, we avoid splitting any municipality.
Validation
Checklist
TODO
lines from the template code have been removedenforce_style()
to format my coderedist_map
andredist_plans
objects, and summary statistics) have been edited@CoryMcCartan