2010 Mississippi Congressional Districts

[emmaebowe]

2010 Mississippi Congressional Districts

Redistricting requirements

In Mississippi, districts must:

1. be contiguous
2. have equal populations
3. be geographically compact
4. preserve county and municipality boundaries as much as possible
5. be VRA compliant (Voting Rights Act, 1965)

Algorithmic Constraints

We ensure that there is a majority minority district with at least 55% VAP.

Data Sources

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

Pre-processing Notes

No manual pre-processing decisions were necessary.

Simulation Notes

We sample 5,000 districting plans for Mississippi, across two independent runs of the SMC algorithm. We apply a hinge Gibbs constraint of strength 20 to encourage drawing a majority black district.

Validation

SMC: 5,000 sampled plans of 4 districts on 1,969 units
`adapt_k_thresh`=0.985 • `seq_alpha`=0.5
`est_label_mult`=1 • `pop_temper`=0

Plan diversity 80% range: 0.38 to 0.70

R-hat values for summary statistics:
    pop_overlap       total_vap        plan_dev       comp_edge     comp_polsby       pop_white       pop_black 
      1.0084891       1.0124108       1.0058790       1.0271944       1.0193987       1.0177382       1.0199021 
       pop_hisp        pop_aian       pop_asian        pop_nhpi       pop_other         pop_two       vap_white 
      1.0032726       1.0140115       1.0089153       1.0103679       1.0122150       1.0345978       1.0183971 
      vap_black        vap_hisp        vap_aian       vap_asian        vap_nhpi       vap_other         vap_two 
      1.0191580       1.0096793       1.0209597       1.0088115       1.0084311       1.0032877       1.0339237 
 pre_16_rep_tru  pre_16_dem_cli  pre_20_rep_tru  pre_20_dem_bid  uss_18_rep_wic  uss_18_dem_bar uss_r18_rep_hyd 
      1.0107785       1.0163042       1.0091060       1.0042825       1.0109173       1.0059316       1.0102071 
uss_r18_dem_esp  uss_20_rep_hyd  uss_20_dem_esp          adv_16          adv_18          adv_20          arv_16 
      1.0235326       1.0097121       1.0088850       1.0163042       1.0059316       1.0044475       1.0107785 
         arv_18          arv_20   county_splits     muni_splits             ndv             nrv         ndshare 
      1.0109173       1.0095682       0.9998345       1.0060653       1.0112088       1.0104340       1.0120143 
        e_dvs.x         e_dem.x         pbias.x          egap.x         e_dvs.y         e_dem.y         pbias.y 
      1.0116374       1.0002001       1.0010777       1.0026766       1.0116374       1.0002001       1.0010777 
         egap.y 
      1.0026766 

Sampling diagnostics for SMC run 1 of 2 (2,500 samples)
         Eff. samples (%) Acc. rate Log wgt. sd  Max. unique Est. k 
Split 1     1,906 (76.2%)     11.8%        0.31 1,584 (100%)     10 
Split 2     1,427 (57.1%)     15.4%        0.67 1,462 ( 93%)      6 
Split 3     1,061 (42.4%)      7.3%        0.96 1,197 ( 76%)      4 
Resample       227 (9.1%)       NA%        3.04   831 ( 53%)     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     1,896 (75.8%)      8.4%        0.30 1,554 ( 98%)     14 
Split 2     1,426 (57.0%)     11.7%        0.72 1,423 ( 90%)      8 
Split 3     1,279 (51.2%)      6.1%        1.01 1,184 ( 75%)      5 
Resample      454 (18.2%)       NA%        2.98   960 ( 61%)     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 @christopherkenny @tylersimko

[emmaebowe]

[christopherkenny]

Hey @emmaebowe, looks like there are similar github/code issues with the wrong files here, as in #155 . (repeated below)

• there are a bunch of other files, but none for MD 2010 here. Can you revise the code so that can be reviewed too?
• the summary shows some duplicated columns with names (*.x and *.y). Do you know what happened there?
• the documentation is missing in the PR

Can you give that a look? Thanks

[emmaebowe]

@christopherkenny Thanks so much! File upload issue should be resolved. Could the summary stats duplication be a GEOID issue?

[emmaebowe]

summary stats issue resolved!

[christopherkenny]

Thanks Emma!