To preserve the cores of prior districts, we merge all precincts which are more than two precincts away from a district border, under the 2010 plan. Precincts in counties which are split by existing district boundaries are merged only within their county.
Simulation Notes
We sample 5,000 districting plans for Kansas across four 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 3,907 units
`adapt_k_thresh`=0.985 • `seq_alpha`=0.7
`est_label_mult`=1 • `pop_temper`=0
Plan diversity 80% range: 0.29 to 0.70
R-hat values for summary statistics:
pop_overlap total_vap plan_dev comp_edge comp_polsby pop_white
1.013543 1.006512 1.000904 1.012780 1.021304 1.008013
pop_black pop_hisp pop_aian pop_asian pop_nhpi pop_other
1.002621 1.000982 1.009344 1.010264 1.010760 1.008708
pop_two vap_white vap_black vap_hisp vap_aian vap_asian
1.012561 1.010236 1.007950 1.000311 1.009257 1.010967
vap_nhpi vap_other vap_two pre_16_dem_cli pre_16_rep_tru pre_20_dem_bid
1.009118 1.014380 1.013490 1.009830 1.020055 1.010805
pre_20_rep_tru uss_16_dem_wie uss_16_rep_mor uss_20_dem_bol uss_20_rep_mar gov_18_dem_kel
1.008497 1.004944 1.001842 1.011967 1.004842 1.013116
gov_18_rep_kob atg_18_rep_sch atg_18_dem_swa sos_18_rep_sch sos_18_dem_mcc adv_16
1.006942 1.001122 1.011482 1.005231 1.011130 1.008358
adv_18 adv_20 arv_16 arv_18 arv_20 county_splits
1.013540 1.011396 1.007235 1.003480 1.005554 1.003842
muni_splits ndv nrv ndshare e_dvs e_dem
1.009800 1.013994 1.004894 1.004910 1.004952 1.002131
pbias egap
1.002125 1.003052
Sampling diagnostics for SMC run 1 of 4 (1,250 samples)
Eff. samples (%) Acc. rate Log wgt. sd Max. unique Est. k
Split 1 1,197 (95.7%) 4.6% 0.33 791 (100%) 12
Split 2 1,068 (85.5%) 6.7% 0.39 785 ( 99%) 7
Split 3 1,146 (91.7%) 3.3% 0.43 679 ( 86%) 4
Resample 1,046 (83.6%) NA% 0.42 1,047 (133%) NA
Sampling diagnostics for SMC run 2 of 4 (1,250 samples)
Eff. samples (%) Acc. rate Log wgt. sd Max. unique Est. k
Split 1 1,198 (95.9%) 6.1% 0.33 787 (100%) 9
Split 2 1,153 (92.3%) 7.7% 0.36 790 (100%) 6
Split 3 1,130 (90.4%) 3.2% 0.43 656 ( 83%) 4
Resample 1,016 (81.2%) NA% 0.45 1,015 (128%) NA
Sampling diagnostics for SMC run 3 of 4 (1,250 samples)
Eff. samples (%) Acc. rate Log wgt. sd Max. unique Est. k
Split 1 1,194 (95.5%) 5.4% 0.34 802 (101%) 10
Split 2 1,077 (86.1%) 7.6% 0.41 776 ( 98%) 6
Split 3 923 (73.8%) 3.3% 0.54 646 ( 82%) 4
Resample 521 (41.7%) NA% 0.54 936 (118%) NA
Sampling diagnostics for SMC run 4 of 4 (1,250 samples)
Eff. samples (%) Acc. rate Log wgt. sd Max. unique Est. k
Split 1 1,194 (95.6%) 5.0% 0.34 785 ( 99%) 11
Split 2 1,148 (91.9%) 6.6% 0.37 775 ( 98%) 7
Split 3 1,053 (84.2%) 2.5% 0.49 685 ( 87%) 5
Resample 806 (64.5%) NA% 0.49 998 (126%) 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.
Redistricting requirements
In Kansas, under the Guidelines And Criteria For 2012 Kansas Congressional And Legislative Redistricting districts must:
Algorithmic Constraints
We enforce a maximum population deviation of 0.5%.
Data Sources
Data for Kansas comes from the ALARM Project's 2020 Redistricting Data Files.
Pre-processing Notes
To preserve the cores of prior districts, we merge all precincts which are more than two precincts away from a district border, under the 2010 plan. Precincts in counties which are split by existing district boundaries are merged only within their county.
Simulation Notes
We sample 5,000 districting plans for Kansas across four independent runs of the SMC algorithm. No special techniques were needed to produce the sample.
Validation
Checklist
TODOlines from the template code have been removedenforce_style()to format my coderedist_mapandredist_plansobjects, and summary statistics) have been edited@CoryMcCartan
Additional Notes