Peak β shifts from rank 2 in small munis to rank 3 in runoff munis
🟡 Peak β shifts from final rank 2 in small munis (β = +10.14, p < 0.001) to rank 3 in runoff-eligible munis (β = +9.43, p = 0.012). The position of the heterogeneity peak moves precisely where Cox's M+1 rule says it should — M+1 = 2 in plurality (small) munis, M+1 = 3 in runoff-eligible munis.
Single-source 🟡: the runoff cell has only n_self = 83, so the rank-2-vs-rank-3 gap within runoff munis is not statistically distinguishable on its own. The test passes on position of peak, not on gap magnitude. Upgrade to 🟢 when 2022 governor races expand the runoff cell.
Sources.
- Own analysis:
build/table/heterogeneity.csv; AN-004 - Cross-refs: H6 coordination-peak; H7 bandwagon-peak; theory.md § Polls as coordination devices; voter-mechanism-coordination interpretation
Cited analyses
Peak β shifts from rank 2 in small munis (+10.14) to rank 3 in runoff-eligible munis (+9.43). Direction matches Cox's M+1 rule (M+1=2 vs M+1=3); bandwagon would predict rank 2 in both. The cleanest design-level discriminator the project supports with current data.