Re-run 2020 Arkansas Congressional Districts

[geogar3]

Redistricting requirements

In Arkansas, there are no state law requirements for congressional districts.

Interpretation of requirements

We enforce a maximum population deviation of 0.5%, which is in line with the low deviation seen in past congressional district maps. We limit the number of county/municipality splits, which is in line with the small number of county/municipality splits observed in past congressional district maps.

Data Sources

Data for Arkansas comes from the ALARM Project's 2020 Redistricting Data Files. Data for Arkansas' 2020 congressional district map comes from All About Redistricting's Maps for Download.

Pre-processing Notes

No manual pre-processing decisions were necessary.

Simulation Notes

We sample 5,000 districting plans for Arkansas across two independent runs of the SMC algorithm. No special techniques were needed to produce the sample.

Validation

SMC: 5,000 sampled plans of 4 districts on 2,747 units
`adapt_k_thresh`=0.985 • `seq_alpha`=0.5
`est_label_mult`=1 • `pop_temper`=0

Plan diversity 80% range: 0.47 to 0.82

R-hat values for summary statistics:
     total_vap       plan_dev      comp_edge    comp_polsby       pop_hisp      pop_white      pop_black       pop_aian      pop_asian 
     1.0006595      1.0006705      1.0033898      1.0017817      1.0026789      1.0020468      1.0017951      1.0035190      1.0008060 
      pop_nhpi      pop_other        pop_two       vap_hisp      vap_white      vap_black       vap_aian      vap_asian       vap_nhpi 
     0.9999961      1.0014038      0.9998751      1.0027249      1.0018856      1.0011615      1.0040176      1.0008058      0.9998848 
     vap_other        vap_two pre_16_rep_tru pre_16_dem_cli uss_16_rep_boo uss_16_dem_eld gov_18_rep_hut gov_18_dem_hen atg_18_rep_rut 
     1.0006162      1.0000847      1.0006022      1.0029601      1.0014641      1.0040816      1.0018785      1.0009145      1.0013890 
atg_18_dem_lee sos_18_rep_thu sos_18_dem_inm pre_20_rep_tru pre_20_dem_bid uss_20_rep_cot uss_20_dem_har         arv_16         adv_16 
     1.0015779      1.0013111      1.0016825      1.0021395      1.0025742      1.0015275      1.0021087      1.0011969      1.0032071 
        arv_18         adv_18         arv_20         adv_20  county_splits    muni_splits            ndv            nrv        ndshare 
     1.0013291      1.0014035      1.0016574      1.0026355      1.0003920      1.0006083      1.0009212      1.0013638      1.0026440 
         e_dvs         pr_dem          e_dem          pbias           egap 
     1.0026577      1.0015256      1.0011547      1.0061662      1.0026662 

Sampling diagnostics for SMC run 1 of 2 (2,500 samples)
         Eff. samples (%) Acc. rate Log wgt. sd  Max. unique Est. k 
Split 1     2,408 (96.3%)     10.4%        0.39 1,580 (100%)     12 
Split 2     2,405 (96.2%)     13.9%        0.37 1,559 ( 99%)      7 
Split 3     2,373 (94.9%)      7.8%        0.46 1,439 ( 91%)      4 
Resample    1,949 (78.0%)       NA%        0.43 1,496 ( 95%)     NA 

Sampling diagnostics for SMC run 2 of 2 (2,500 samples)
         Eff. samples (%) Acc. rate Log wgt. sd  Max. unique Est. k 
Split 1     2,413 (96.5%)     11.9%        0.38 1,591 (101%)     10 
Split 2     2,405 (96.2%)     15.9%        0.36 1,553 ( 98%)      6 
Split 3     2,377 (95.1%)      7.9%        0.46 1,430 ( 90%)      4 
Resample    1,965 (78.6%)       NA%        0.42 1,494 ( 95%)     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 master 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

delete this line and all the tags except the reviewers you need @CoryMcCartan @christopherkenny