Re-run 2020 Idaho Congressional Districts

[christopherkenny]

Redistricting requirements

In Idaho, districts must:

1. be contiguous (72-1506(6)).
2. have equal populations (72-1506(3)).
3. be geographically compact (72-1506(4), 72-1506(5)).
4. preserve county and municipality boundaries as much as possible (72-1506(2)).
5. not be drawn to favor party or incumbents (72-1506(8)).
6. connect counties based on highways (72-1506(9)).

Interpretation of requirements

We enforce a maximum population deviation of 0.5%.

Data Sources

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

Pre-processing Notes

Borders between counties which are not connected by highways were removed.

Simulation Notes

We sample 5,000 districting plans for Idaho, across 2 independent runs of the SMC algorithm. We sample using the standard algorithmic county constraint. No special techniques were needed to produce the sample.

Validation

SMC: 5,000 sampled plans of 2 districts on 931 units
`adapt_k_thresh`=0.985 • `seq_alpha`=0.5
`est_label_mult`=1 • `pop_temper`=0

Plan diversity 80% range: 0.081 to 0.689

R-hat values for summary statistics:
   pop_overlap      total_vap       plan_dev      comp_edge    comp_polsby       pop_hisp 
     1.0002363      1.0004242      0.9999541      1.0000043      0.9999779      1.0005757 
     pop_white      pop_black       pop_aian      pop_asian       pop_nhpi      pop_other 
     1.0006040      1.0003794      1.0016616      1.0010224      1.0007242      0.9998282 
       pop_two       vap_hisp      vap_white      vap_black       vap_aian      vap_asian 
     1.0003301      1.0004728      1.0003179      1.0003911      1.0008968      1.0010054 
      vap_nhpi      vap_other        vap_two pre_16_rep_tru pre_16_dem_cli uss_16_rep_cra 
     1.0010067      0.9998171      1.0007871      1.0000033      1.0012958      1.0001750 
uss_16_dem_stu gov_18_rep_lit gov_18_dem_jor atg_18_rep_was atg_18_dem_bis sos_18_rep_den 
     1.0009342      1.0002236      1.0012880      1.0000707      1.0011649      0.9999729 
sos_18_dem_hum pre_20_rep_tru pre_20_dem_bid uss_20_rep_ris uss_20_dem_jor         arv_16 
     1.0012842      0.9999582      1.0012993      1.0001819      1.0012768      0.9999313 
        adv_16         arv_18         adv_18         arv_20         adv_20  county_splits 
     1.0010860      1.0001590      1.0012893      1.0000273      1.0012670      0.9998131 
   muni_splits            ndv            nrv        ndshare          e_dvs           egap 
     1.0002937      1.0013479      1.0000786      1.0005925      1.0007021      1.0001430 

Sampling diagnostics for SMC run 1 of 2 (2,500 samples)
         Eff. samples (%) Acc. rate Log wgt. sd  Max. unique Est. k 
Split 1     2,433 (97.3%)      3.8%        0.34 1,591 (101%)      6 
Resample    2,266 (90.7%)       NA%        0.34 1,534 ( 97%)     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     2,432 (97.3%)      4.0%        0.34 1,593 (101%)      6 
Resample    2,267 (90.7%)       NA%        0.34 1,532 ( 97%)     NA 

•  Watch out for low effective samples, very low acceptance rates (less than 1%), large std.
devs. of the log weights (more than 3 or so), and low numbers of unique plans. R-hat values
for summary statistics should be between 1 and 1.05.

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

@CoryMcCartan