2010 Kentucky Congressional Districts

[kevpwang]

Redistricting requirements

In Kentucky, under the Criteria and Standards for Congressional Redistricting adopted by Interim Joint Committee on State Government’s Redistricting Subcommittee in 1991, districts must:

1. be contiguous
2. have equal populations
3. be geographically compact
4. preserve county and municipality boundaries as much as possible
5. preserve communities of interest as much as possible

Algorithmic Constraints

We enforce a maximum population deviation of 0.5%. We use a pseudo-county constraint described below which attempts to mimic the norms in Kentucky of generally preserving county, city, and township boundaries.

Data Sources

Data for Kentucky comes from the ALARM Project's 2020 Redistricting Data Files.

Pre-processing Notes

No manual pre-processing decisions were necessary.

Simulation Notes

We sample 8,000 districting plans for Kentucky across two independent runs of the SMC algorithm, and then thin the sample down to 5,000 plans. We use a pseudo-county constraint to limit the county and municipality (i.e. city and township) splits. Municipality lines are used in Jefferson County, which has a population larger than the target population for a congressional district.

Validation

SMC: 5,000 sampled plans of 6 districts on 1,115 units
`adapt_k_thresh`=0.985 • `seq_alpha`=0.5      
`est_label_mult`=1 • `pop_temper`=0           
ℹ Computing summary statistics for KY_cd_2010
Plan diversity 80% range: 0.51 to 0.80        
ℹ Computing summary statistics for KY_cd_2010
R-hat values for summary statistics:
   pop_overlap      total_vap       plan_dev      comp_edge    comp_polsby      pop_white      pop_black 
      1.000675       1.000500       1.003909       1.002915       1.005447       1.001063       1.000897 
      pop_hisp       pop_aian      pop_asian       pop_nhpi      pop_other        pop_two      vap_white 
      1.002734       1.004164       1.004969       1.001571       1.000456       1.001518       1.000505 
     vap_black       vap_hisp       vap_aian      vap_asian       vap_nhpi      vap_other        vap_two 
      1.001050       1.002371       1.004039       1.004584       1.003398       1.001579       1.002407 
pre_16_rep_tru pre_16_dem_cli uss_16_rep_pau uss_16_dem_gra         adv_16         arv_16  county_splits 
      1.004017       1.001787       1.004750       1.000248       1.000165       1.009719       1.001581 
   muni_splits            ndv            nrv        ndshare          e_dvs          e_dem          pbias 
      1.000385       1.000165       1.009719       1.001076       1.001128       1.001735       1.003936 
          egap 
      1.000288 

Sampling diagnostics for SMC run 1 of 2       
         Eff. samples (%) Acc. rate Log wgt. sd  Max. unique Est. k 
Split 1    3,876 (155.0%)     12.0%        0.36 2,519 (159%)      5 
Split 2    3,849 (153.9%)     13.0%        0.36 2,461 (156%)      4 
Split 3    3,797 (151.9%)     15.8%        0.47 2,444 (155%)      3 
Split 4    3,714 (148.6%)     13.1%        0.54 2,393 (151%)      3 
Split 5    3,688 (147.5%)      6.2%        0.52 2,157 (136%)      2 
Resample   2,797 (111.9%)       NA%        0.54 2,292 (145%)     NA 

Sampling diagnostics for SMC run 2 of 2       
         Eff. samples (%) Acc. rate Log wgt. sd  Max. unique Est. k 
Split 1    3,876 (155.0%)      8.4%        0.36 2,521 (160%)      7 
Split 2    3,846 (153.8%)     10.2%        0.36 2,521 (160%)      5 
Split 3    3,817 (152.7%)     11.7%        0.45 2,473 (156%)      4 
Split 4    3,725 (149.0%)     12.9%        0.53 2,414 (153%)      3 
Split 5    3,725 (149.0%)      4.3%        0.50 2,197 (139%)      3 
Resample   2,956 (118.3%)       NA%        0.52 2,319 (147%)     NA 

Checklist

• [x] I have followed the instructions
• [x] I have updated the tracker
• [x] All TODO lines from the template code have been removed
• [x] I have merged in the main branch and then recalculated summary statistics
• [x] I have run enforce_style() to format my code
• [x] The documentation copied above is up-to-date
• [x] There are no data files in this pull request
• [x] None of the file output paths (for the redist_map and redist_plans objects, and summary statistics) have been edited

@christopherkenny