Within-candidate FE on 568 self-sponsored candidate-poll rows gives β = +7.75 pp (p<0.001) — large, robust to spec, robust to renormalization choice. The opponent-sponsored coefficient is -1.93 (p=0.030), so the bias is sender-specific not a generic house effect.

Restricting comparators to media-or-pollster-self polls in the same race within the same week (Spec 3c) gives β = +6.95 pp (p=0.008) on 60 race-week cells. The tightest design and the most robust to the timing-of-commission alternative.

For 132 candidates whose self-sponsored poll was preceded by an independent poll in the same race (median gap 10 days), the within-candidate jump from preceding-independent to self-sponsored error is +6.70 pp (t=5.21). The most intuitive counter to "self-sponsor when leading".

χ²(5) = 2.31, p = 0.80 on the joint party × sponsor interaction — by-party point-estimate dispersion in the subset regressions of robustness.md §3 is not statistically distinguishable from noise around the pooled β. The pooled +7.92 (OTHER baseline) is a sufficient summary; the apparent MDB null was a reduced-power artifact of subset regression, not a real party effect.

Headline survives the five red-team substitutions. K1 (media-only comparator) preserves β at +7.59 with n→253; K3 (Route B vice-prefeito) is falsified upstream (0/429 vice matches); K4 (drop_absorbed) restores β at +8.00 under race-FE-only — within-candidate-FE selection is not generating β; K5 (drop Route D) raises β to +9.30. K2 (raw percent, no renormalization) attenuates β to +5.10 — the within-(protocol × scenario_label) renormalization contributes ~3 pp of the headline magnitude; the residual +5.10 on raw percent is the conservative β to cite alongside the +7.98 renormalized number.

Permutation null (B=500) rejects at p < 0.002: 0/500 within-(race × week) random shuffles of sponsored_by produce β as extreme as the observed +4.68 (race-week FE only; the +7.94 candidate+race-week-FE headline is yet further out the same tail). Pollster jackknife (top-20): β range [+7.80, +8.13], sd 0.074 — no single firm drives the result. UF jackknife (26 states): β range [+7.42, +8.32], sd 0.180 — no single state drives the result. The +7.98 spec-2 baseline survives every leave-one-out.

Wild-cluster bootstrap on the race-week-FE-only spec (β=+4.68, n=448, G=51 muni clusters): WCR two-sided p = 0.0175 (B=2000 Rademacher draws); WCU 95% percentile CI [+1.09, +8.29] and percentile-t CI [+0.88, +8.50]. WLS spec-2 weighted by sample_size: β=+8.15 (SE 1.42, p<0.001) — within 0.18 pp of the unweighted baseline. Week-window sensitivity (`%U` baseline vs `%V` ISO vs 10-day vs 14-day rolling): β range [+4.16, +5.31], all p < 0.02 — the race-week-FE-only spec is not brittle to the week-boundary definition. The proper spec-3c TWFE wild-cluster bootstrap (candidate FE + race-week FE) is parked as a follow-up; the rejection here on the more conservative spec extends to the headline a fortiori.

Crude per-candidate post-fielding tampering ruled out by within-sponsored-poll digit forensics; broader fabrication channels NOT ruled out. Round-number frequency indistinguishable between sponsor's own candidate (18.2 % integers) and other candidates in the same sponsored poll (17.7 %; A vs B z=+0.26, p=0.79). Mult-of-5 indistinguishable (4.1 % vs 3.7 %; z=+0.45, p=0.66). Tenths-digit distribution for values ≥ 5 has the same shape across A and B (digit-0 share 20.4 % vs 20.3 %). Group A's Benford first-digit shift toward 4–5–6 vs B's 1–2–3 reflects sponsors polling viable candidates (30–60 % range), not numerical manipulation: Group B inside the same sponsored polls follows Benford normally. **Blind spots of this test:** sophisticated manipulation that preserves digit distributions, proportional within-poll rescaling, and any pre-publication data work (quota reweighting, dropping strata, re-running) leave no digit signature and are NOT addressed here. Substantive read: the +7-8 pp average is not produced by crude per-candidate edits leaving digit fingerprints; the broader question of whether design-driven (Channel A) or sophisticated/pre-publication (Channel B) mechanisms dominate is the companion paper's job.

Three forensics targeting the AN-013 blind spots — design-respecting fabrication — return **two clean nulls and one ambiguous-cause positive**. (T1) Standardised-error variance test: var(z|sponsored, demeaned) = 79.7 vs var(z|indep, demeaned) = 315.3; F-test ratio 0.253 p<0.0001 but Levene's median-centred p = 0.122 — the F-test result is outlier-driven; sponsored polls are NOT 'too clean' (var of 80 σ² means SD ≈ 9 σ around the bias mean, plenty of spread). (T2) Bias-concentration test: sponsored polls have 11.5 % within ±2pp of own mean vs 19.0 % for indep (z = −4.75, p < 0.0001 in the *anti*-fabrication direction — sponsored polls are MORE spread, not less). (T3) Within-firm rounding TVD on tenths-digit of poll_percent_raw: 12 firms qualify with ≥10 sponsored and ≥10 indep each; mean TVD = 0.39 (vs ~0.15-0.20 expected under H0); 3 of 12 firms significant at chi-square p<0.05 (vs 0.6 expected). Read: T1+T2 argue *against* simple sample-design-consistent fabrication as the headline mechanism — the sponsored-error distribution is wider, not tighter, than the indep distribution. T3 picks up real within-firm processing differences (could be differential subcontracting, customer-specific reporting templates, or fabrication; cause is not separable from this test). Combined with AN-013 v1 (no per-row digit-tampering signature), the cumulative weight of evidence is that **the +7 pp is not concentrated in a single big fabrication lever**. The residual likely lives in a constellation of small effects across sample-frame contamination (1-4 pp prior), interviewer scripting (0-2 pp), and strategic timing (1-2 pp), each individually modest.

Red-team K2 hypothesis falsified. **Sponsors do not list fewer candidates.** Within-candidate denominator gap (sponsored poll − non-sponsored polls, n = 226 candidates with within-variation): median +0.15, mean −2.61, 50 % of candidates have a positive gap. Cell-level sponsored cells in fact have *larger* denominators (91.74 vs 78.68; Welch p < 0.0001 in the *opposite* direction from the red-team conjecture). The K2 renormalized-vs-raw gap (+1.31 pp within-candidate, +2.88 pp in the regression spec) is the mechanical multiplicative scaling of renormalization on a non-zero raw effect: predicted gap under H₀ 'denominators identical within candidate' = +6.08 × 1.198 = +7.29 pp, observed +7.40 pp, residual +0.11 pp — **98.6 % of the renormalized gap is the multiplicative effect, 1.4 % is any denominator shift**. The Channel-A characterization should not include 'sponsors list fewer candidates'; that lever is empirically absent.

Data-quality concern dispatched. Three of four extraction-quality proxies (denom_dist, n_named, mean_match) are statistically indistinguishable between sponsored and independent cells; the fourth (denom) differs in the *opposite* direction from a 'sponsored polls have fewer extracted candidates' hypothesis (+13.06, p<10⁻¹⁵). Spec 2 augmented with denom_dist + mean_match controls leaves β unchanged at +8.00. The clean-denominator subset (denom ∈ [80, 110]) gives β=+5.39, equal to the AN-010 K2 raw β of +5.10 — consistent with AN-014's mechanical-multiplicative-scaling story (scale factor ≈ 1 when denom ≈ 100) rather than any data-quality artifact. Outlier audit on the top-10 sponsored-row errors shows a mix of inflation and deflation (poll%=100 and poll%=0 cases), not a systematic upward bias. The proper within-firm test is parked as a follow-up: top-5 pollsters by row count don't sponsor enough polls to estimate within-firm β; need to refit on firms that DO sponsor (the customer-mix sorting set from AN-007).

Data-quality concern definitively dispatched **and** a substantively new finding surfaces: dramatic between-firm β heterogeneity. Within-firm β (15 firms ≥ 10 sponsored rows; 31 firms ≥ 5): mean +6.5 / +7.2, median +4.4 / +6.3, **range [−11, +35], sd 10.3**. 19 of 31 firms (61 %) are individually significant at p < 0.05; 22/31 positive. **Big-name firms (CENSUS, IIP, INSTITUTO PARANÁ, Verita) have β near zero or modestly negative within-firm; smaller firms (METHODUS +24.7, CAMARGO +23.6, INTENÇÃO +35.2, DATA SC +16.1) slant heavily.** Because PDF style and LLM-extraction pattern are held strictly fixed within firm, the cross-firm β dispersion (sd 10.3 pp) is *real cross-firm sponsor-behavior heterogeneity*, not data-quality artifact. The data-quality concern is closed.

**Variance decomposition of the headline +7 pp: 100 % within-firm, ~0 % between-firm sponsor selection.** Spec A (cand FE only, headline replicate): β = +7.85 pp (SE 1.24, p ≈ 2.6 × 10⁻¹⁰). Spec B (cand FE + firm FE, the within-firm sponsor effect averaged across all 426 firms in the analysis sample): β = +7.98 pp (SE 1.25, p ≈ 1.9 × 10⁻¹⁰). The between-firm component (A − B) is **−0.13 pp**. The +7 pp is not 'sponsors hire firms that systematically over-state' — it is 'firms slant when paid by candidates, regardless of which firm'. Same firm, same pollster style, different customer → +8 pp. The firm-level slant-for-hire selection hypothesis (2-4 pp prior in docs/thinking.md residual decomposition) is structurally ruled out at headline scale. AN-016's within-firm β dispersion (sd 10.3) is still real; AN-018's size-discipline (small firms slant more among the 31 firms ≥ 5 sponsored) still holds; AN-059's decomposition says sponsors do not preferentially load on the high-slant firms in the universe at large.

Restricting the Spec 3c clean comparator to media-only polls (dropping pollster-self) gives β = +8.15 pp (p = 0.036, n = 165 rows / 28 race-week cells) — if anything larger than the media-or-pollster-self spec. Pollster-self inclusion is not pulling the headline up.

Multiway (muni × pollster) clustering moves spec-2 SE 1.04 → 1.07; candidate-level clustering 1.04 → 1.14. Wild-cluster restricted bootstrap p-values are < 1/2000 for both spec 2 and spec 3c (the small-cluster spec where it matters most). Inference is robust to all three sensitivities.

Benjamini-Hochberg FDR correction on the 10 within-pair Channel-A directional tests. 6 of 10 survive at q < 0.05 and 7 of 10 at q < 0.10. The only 'small positive, marginal' lever (population-frame mismatch, p = 0.12) does NOT survive correction (q_BH = 0.15), sharpening the 'no single lever carries +7 pp' conclusion.

Structural bound on scenario-pick effect: 93.2% of mayoral protocols have only ONE estimulado scenario; the canonical-pick choice is degenerate for them. Among the 6.8% multi-scenario subset (616 protocols, max 11 scenarios), median within-candidate spread across scenarios is 3.15 pp. Aggregate scenario-pick effect on β is therefore bounded at <0.2 pp — well below the +7 pp headline.

Spec 2 sponsor-label permutation null: 500 random reassignments of sponsored_by across the FWL-residualized panel produce a null distribution centered on 0.005 pp (sd 0.62, max |β| = 2.07). The observed β = +6.86 pp is unreachable in 500 draws — permutation p < 1/B (= 0.002), about 11 null SDs away from the observed magnitude.

Same-poll sponsor-vs-top-opponent DiD: +8.2 pp (t = 6.43, n = 239 pairs, 64% positive). The sponsor's candidate's error jumps MORE between matched independent and sponsored polls than the top opponent's error does. Large sponsor-specific shift consistent with either per-candidate slant or sample-design favoring the sponsor's voter base.

Event-study figure of independent-poll polling error in ±4 weeks around each self-sponsored poll. Independent bins hover near zero error; the self-sponsored event-day point sits at +7.4 pp (SE 0.93). Visualizes the within-candidate trajectory test.

Headline β robust to all SE choices. Spec 2 β = +6.86 pp (SE 0.81–1.14 across cluster_muni/race_week/politico_id/twoway/wcr_race_week; t ≥ 6.0; all p<0.001). Spec 3c β = +7.91 pp (SE 2.30–2.64; t ≥ 3.0; all p ≤ 0.004; wcr-bootstrap t=6.1). AN-110's empirical noise floor is mechanism evidence, not a threat to the aggregate result. No decisions.md walk-back.

SP-only prototype (2026-06-01): within-candidate FE gave β = +7.24 pp on 15 self-sponsored rows. Superseded by AN-001's all-Brazil run but kept as the project's first-pass design validation.

Firm-race coverage proxy for the publication-selection alternative. In the runoff-eligible 172-muni sample, sponsored polls of firms with NO media coverage show MORE bias (mean error +15.2 pp, n=10) than sponsored polls of firms WITH coverage (+7.2 pp, n=28) — the opposite of what publication selection predicts. n=10 is too thin for inference, but the direction does not support publication selection driving the headline.

No cross-sectional correlation between per-firm polling accuracy (MAE on non-self-sponsored polls) and within-firm sponsor β. Pearson r = −0.09 (p = 0.68) on 22 firms. The reputation channel in §sec:policy operates through volume/visibility (AN-018), not through accuracy as a standalone signal.