gbanyan
9e68f2e1d3
Resolved Codex review (gpt-5.5 xhigh) findings against b6913d2.
BLOCKERS:
- Appendix B reference mismatch: rewrote all main-text "Appendix B" references
to "supplementary materials" since Appendix B is now a redirect stub. Affected
the SSIM design-argument pointer, threshold provenance, byte-level
decomposition, MC band capture-rate, and backbone-ablation table references
across §III-F / §III-H.1 / §III-H.2 / §III-K / §III-L.4 / §III-M / §IV-F /
§IV-J / §IV-K / §IV-L / §V-C / §V-H.
- Table rendering: un-commented Tables I-IV (Dataset Summary, YOLO Detection,
Extraction Results, Cosine Distribution Statistics) which were inside HTML
comment blocks and would not have rendered in the submission.
- Table numbering out of order: Table XIX appeared before Tables XVI-XVIII.
Renumbered XIX -> XVI (document-level worst-case counts), XVI -> XVII (Firm x
K=3 cross-tab), XVII -> XVIII (K=3 component comparison), XVIII -> XIX
(Spearman correlation). Cross-references updated in §IV-J / §IV-K and §V-C.
- Table V mis-citation: §IV-C said "KDE crossover ... (Table V)" but Table V is
the dip test. Dropped the (Table V) tag; crossover is a textual finding.
- Submission cleanup: wrapped the archived Impact Statement section heading and
body inside the existing HTML comment (was rendering). Funding placeholder
wrapped in HTML comment with a TO-DO note (won't render but is preserved as
reminder).
MAJORS:
- Line 1077 numerical conflation: rewrote the §V-C / §III-L.4 paragraph that
labelled Firm A's per-document HC+MC inter-CPA proxy ICCR of 0.6201 as a rate
"on real same-CPA pools." 0.6201 is a counterfactual proxy under inter-CPA
candidate-pool replacement, not the observed rate. Added explicit disambig:
the corresponding observed rate from Table XVI (formerly XIX) is 97.5%
HC+MC for Firm A; the proxy and observed rates measure different quantities.
- Residual "validation" language softened: "Dual-descriptor verification" ->
"Dual-descriptor similarity"; "we validate the backbone choice" -> "we
support the backbone choice"; "pixel-identity validation" -> "pixel-identity
positive-anchor check"; "## M. Validation Strategy and Limitations under
Unsupervised Setting" -> "## M. Unsupervised Diagnostic Strategy and Limits".
- "Specificity behaviour" overclaim: "characterises the cosine threshold's
specificity behaviour" -> "specificity-proxy behaviour" (methodology §III-L.0
and discussion §V-F).
- "Prior published / prior calibration" ambiguity: replaced "prior published
per-comparison rate" with "the corpus-wide rate reported in §IV-I"; replaced
"(prior published operating point)" with "(alternative operating point from
supplementary calibration evidence)" in Tables XXI; replaced "prior reporting
and the existing literature" with "the existing literature and the
supplementary calibration evidence."
MINORS:
- Line 116 Bayes-optimal qualifier: "the local density minimum ... is the
Bayes-optimal decision boundary under equal priors" -> "In idealized
two-class mixture settings with equal priors and equal misclassification
costs, the local density minimum ... coincides with the Bayes-optimal
decision boundary."
- Stale section refs: §V-G for the fine-tuning caveat retargeted to §V-H
Engineering-level caveats (where it lives after the §V-H reorganisation);
§III-L for the worst-case rule retargeted to §III-H.1; "Section IV-D.2"
(nonexistent) retargeted to "Section IV-D Table VI."
- Abstract / Introduction "after pool-size adjustment": separated the
document-level D2 proxy ICCR claim from the per-signature logistic regression
claim. Now: "Per-document D2 inter-CPA proxy ICCRs differ by an order of
magnitude across firms ... a per-signature logistic regression confirms the
firm gap persists after pool-size control."
NIT:
- Related Work HTML comment "(see paper_a_references_v3.md for full list)"
-> "(full list in the References section)"; removes the version-coded
filename reference from the source.
Artefacts:
- Combined manuscript regenerated: paper_a_v4_combined.md, 1312 lines.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
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# Appendix A. BD/McCrary Bin-Width Sensitivity (Signature Level)
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The main text (Section III-I, Section IV-D Table VI) treats the Burgstahler-Dichev / McCrary discontinuity procedure [38], [39] as a *density-smoothness diagnostic* rather than as a threshold estimator.
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This appendix documents the empirical basis for that framing by sweeping the bin width across four (variant, bin-width) panels: Firm A and full-sample, each in the cosine and $\text{dHash}_\text{indep}$ direction.
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<!-- TABLE A.I: BD/McCrary Bin-Width Sensitivity (two-sided alpha = 0.05, |Z| > 1.96)
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| Variant | n | Bin width | Best transition | z_below | z_above |
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|---------|---|-----------|-----------------|---------|---------|
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| Firm A cosine (sig-level) | 60,448 | 0.003 | 0.9870 | -2.81 | +9.42 |
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| Firm A cosine (sig-level) | 60,448 | 0.005 | 0.9850 | -9.57 | +19.07 |
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| Firm A cosine (sig-level) | 60,448 | 0.010 | 0.9800 | -54.64 | +69.96 |
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| Firm A cosine (sig-level) | 60,448 | 0.015 | 0.9750 | -85.86 | +106.17 |
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| Firm A dHash_indep (sig-level) | 60,448 | 1 | 2.0 | -4.69 | +10.01 |
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| Firm A dHash_indep (sig-level) | 60,448 | 2 | no transition | — | — |
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| Firm A dHash_indep (sig-level) | 60,448 | 3 | no transition | — | — |
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| Full-sample cosine (sig-level) | 168,740 | 0.003 | 0.9870 | -3.21 | +8.17 |
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| Full-sample cosine (sig-level) | 168,740 | 0.005 | 0.9850 | -8.80 | +14.32 |
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| Full-sample cosine (sig-level) | 168,740 | 0.010 | 0.9800 | -29.69 | +44.91 |
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| Full-sample cosine (sig-level) | 168,740 | 0.015 | 0.9450 | -11.35 | +14.85 |
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| Full-sample dHash_indep (sig-l.) | 168,740 | 1 | 2.0 | -6.22 | +4.89 |
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| Full-sample dHash_indep (sig-l.) | 168,740 | 2 | 10.0 | -7.35 | +3.83 |
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| Full-sample dHash_indep (sig-l.) | 168,740 | 3 | 9.0 | -11.05 | +45.39 |
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-->
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Two patterns are visible in Table A.I.
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First, the procedure consistently identifies a "transition" under every bin width, but the *location* of that transition drifts monotonically with bin width (Firm A cosine: 0.987 → 0.985 → 0.980 → 0.975 as bin width grows from 0.003 to 0.015; full-sample dHash: 2 → 10 → 9 as the bin width grows from 1 to 3).
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The $Z$ statistics also inflate superlinearly with the bin width (Firm A cosine $|Z|$ rises from $\sim 9$ at bin 0.003 to $\sim 106$ at bin 0.015) because wider bins aggregate more mass per bin and therefore shrink the per-bin standard error on a very large sample.
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Both features are characteristic of a histogram-resolution artifact rather than of a genuine density discontinuity.
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Second, the candidate transitions all locate *inside* the high-similarity region (cosine $\geq 0.975$, dHash $\leq 10$) rather than at a between-mode boundary, which is the location pattern we would expect of a clean within-population antimode.
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Taken together, Table A.I shows that the signature-level BD/McCrary transitions are not a threshold in the usual sense---they are histogram-resolution-dependent local density anomalies located *inside* the non-hand-signed mode rather than between modes.
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This observation supports the main-text decision to use BD/McCrary as a density-smoothness diagnostic rather than as a threshold estimator and reinforces the joint reading of Section IV-D that the descriptor distributions do not contain a within-population bimodal antimode that could anchor an operational threshold.
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Raw per-bin $Z$ sequences and $p$-values for every (variant, bin-width) panel are available in the supplementary materials.
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# Appendix B. Reproducibility Materials
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The full table-to-script provenance mapping, script source code, and report artefacts for every numerical table and figure in this paper are provided in the supplementary materials. Scripts run deterministically under fixed random seeds documented there; reviewer reproduction should re-emit artefacts from the listed scripts rather than rely on any local path layout.
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