In Oregon, districts must, under Or. Rev. Stat. § 188.010:
be contiguous
be of equal population
utilize existing geographic or political boundaries
not divide communities of common interest
be connected by transportation links
Additionally, districts may not favor any political party or incumbent, and may not dilute the voting strength of any language or ethnic minority group.
Algorithmic Constraints
We enforce a maximum population deviation of 0.5%.
We apply a county/municipality constraint, as described below.
To reflect the transportation links constraint, we remove edges in the adjacency graph for counties not connected by a state or federal highway.
Oregon does not submit precinct boundaries to the Census Bureau.
The base shapefile consists of tracts.
As described above, counties not linked by a state or federal highway were manually disconnected.
The full list of these counties can be found in the 01_prep_OR_cd_2020.R file.
Simulation Notes
We sample 6,000 districting plans for Oregon across two independent runs of the SMC algorithm.
To balance county and municipality splits, we create pseudocounties for use in the county constraint.
These are counties, outside of Multnomah county. Within Multnomah county, each municipality is its own pseudocounty as well.
Multnomah county were chosen since it is necessarily split by congressional districts.
Redistricting requirements
In Oregon, districts must, under Or. Rev. Stat. § 188.010:
Additionally, districts may not favor any political party or incumbent, and may not dilute the voting strength of any language or ethnic minority group.
Algorithmic Constraints
We enforce a maximum population deviation of 0.5%. We apply a county/municipality constraint, as described below. To reflect the transportation links constraint, we remove edges in the adjacency graph for counties not connected by a state or federal highway.
Data Sources
Data for Oregon comes from the ALARM Project's 2020 Redistricting Data Files.
Pre-processing Notes
Oregon does not submit precinct boundaries to the Census Bureau. The base shapefile consists of tracts. As described above, counties not linked by a state or federal highway were manually disconnected. The full list of these counties can be found in the
01_prep_OR_cd_2020.R
file.Simulation Notes
We sample 6,000 districting plans for Oregon across two independent runs of the SMC algorithm. To balance county and municipality splits, we create pseudocounties for use in the county constraint. These are counties, outside of Multnomah county. Within Multnomah county, each municipality is its own pseudocounty as well. Multnomah county were chosen since it is necessarily split by congressional districts.
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