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AK 2024 Primary — logit

Likely-voter model for AK 2024 PRIM, training target election held Aug 20, 2024.

Test ROC AUC
0.8892
Brier
0.0939
Log loss
0.3055
Positive rate (training)
19%
Eligible voters: 577107
Training sample: 461685
Test sample: 115422

Methodology

Likely-voter model for 2024 PRIM, fitted as a logistic regression on voter-history and demographic features from the AK Division of Elections statewide voter file. Trained on n=461,685 eligible voters (target positive rate 18.7%); test ROC AUC 0.8892; Brier 0.0939. Features were standardized (zero-mean, unit-variance). Top positive coefficients: voted_2022_primary (+0.398), voted_2022_general (+0.384), voted_2020_primary (+0.256), ever_voted_municipal (+0.255), n_prior_special (+0.151). Top negative coefficients: years_since_last_vote (-15.496), share_polls (-13.104), share_absentee (-8.836), share_mail (-6.946), share_questioned (-5.283).

Standardized coefficients (sorted by |magnitude|)

Rank Feature coef (std-scaled)
1 years_since_last_vote -15.4959
2 share_polls -13.1037
3 share_absentee -8.8362
4 share_mail -6.9464
5 share_questioned -5.2829
6 share_early -4.9050
7 voted_2022_primary 0.3976
8 voted_2022_general 0.3842
9 voted_2016_general -0.2629
10 voted_2020_primary 0.2562
11 ever_voted_municipal 0.2546
12 voted_2018_general -0.1851
13 n_prior_special 0.1514
14 years_registered 0.1298
15 ever_voted_primary 0.1165
16 age_at_election 0.1156
17 n_prior_municipal 0.1107
18 party_D 0.0840
19 n_prior_elections 0.0799
20 party_U -0.0684
21 n_prior_primaries 0.0603
22 ever_voted_general 0.0601
23 years_at_district 0.0460
24 party_OTHER -0.0428
25 party_R 0.0416
26 pra_flag_int 0.0371
27 party_L -0.0305
28 voted_2018_primary 0.0256
29 n_prior_generals -0.0233
30 voted_2020_general -0.0232
31 gender_M -0.0183
32 gender_F 0.0182
33 party_G -0.0036
34 gender_U 0.0015
35 party_N 0.0000

Intercept: -2.3888. Coefficients are in standardized units (features were zero-mean / unit-variance scaled before fit).

Calibration — predicted vs. actual turnout by decile

Decile (10 = highest LV) n Pred. p Actual turnout
10 57711 0.724 0.759
9 57711 0.498 0.474
8 57711 0.309 0.288
7 57710 0.161 0.159
6 57711 0.077 0.076
5 57711 0.036 0.038
4 57710 0.024 0.025
3 57711 0.020 0.018
2 57711 0.017 0.018
1 57710 0.009 0.018

Eligible scored voters bucketed into 10 equal-size deciles by predicted probability. A well-calibrated model has predicted p ≈ actual turnout in every decile.

Hyperparameters

{'C': 1.0, 'seed': 42, 'max_iter': 200, 'test_size': 0.2}

Trained on AK Division of Elections statewide voter file snapshot AK DoE 2025-05 at 2026-05-23 04:58 UTC.