Corporate A/G Research Extension SEC public-company structural distress study

Limitations

What this is not, what it is, and what would justify reopening

Corporate A/G is a research-grade extension. Many of the things people might hope a "corporate distress" site would do, this one does not do. Read this page before drawing conclusions from anywhere else.

1. What this is not

2. Main limitations

Single primitives slightly outperform the composite on AUROC

On the Phase-18 test fold, two single-feature baselines — neg_g4_ocf_assets_z (operating cash flow ÷ assets, oriented risk-up) AUROC 0.736 and neg_g2_interest_coverage_z AUROC 0.726 — slightly beat structural_distress_lam0_0 (AUROC 0.711) by 1.5–2.5 pp. The composite’s value is robustness (graceful degradation when one primitive is missing) and regime separation, not maximum raw discrimination.

Low base rate limits precision and F1

Eligible-universe Chapter-11 incidence is on the order of 0.5 – 1.0% per year. Even an AUROC of 0.71 produces low precision at any practical operating threshold; the Watch-band precision is roughly 3%. F1 collapses at low base rate and is not used as a headline metric.

Top-1% tail dropoff

The top 1% of structural-distress scores has lower event rate than the Watch band (80–95th percentile). The very tail is noise-prone. Operators should not treat the top 1% as the highest-action band.

Sector heterogeneity remains

Pooled AUROC 0.711 hides cell-to-cell variation. The Manufacturing-3 (durables / electronics) sector cell shows AUROC 0.639 — meaningfully weaker than the pooled headline. Wholesale / Retail Trade and Manufacturing-2 (food / textiles / chem / petr) are the strongest reliable cells.

Item 1.03 anchor semantics imperfect

Even after the LLM-assisted scope classifier, about 25% of anchored CIKs sit in ambiguous_item_103 or non-direct buckets. The strict-label cohort (231 positives) is the cleanest cell; the all-anchored cohort (354 positives) introduces some scope noise.

XBRL coverage / filtering matters

Companies with thin XBRL coverage are excluded by design. The Phase-12 SIC + facts-size + 3-Assets gates are conservative; some genuinely-distressed firms are filtered out before scoring.

Bankruptcy paths beyond Item 1.03

Chapter-7 cases, Item 5.02 / Item 8.01 attachments, and going-private transactions are not captured by the anchor table.

Divergence / masking — internal evidence only

The Phase-19 divergence-anchor study used an internal future-state anchor (G drops by ≥ 1 z over 1–2 years OR firm enters pre-petition state). The result is suggestive (canonical R AUROC 0.705 within the divergence-state cohort) but it is not external validation. An external divergence-anchor study is a future-phase candidate.

Current company rankings are not published

This site does not distribute per-company distress scores, top-N watchlists, or any ranked list. That is a deliberate constraint, not an oversight.

3. Why it is still worth keeping

4. What would justify reopening corporate

The corporate branch is frozen as of Phase 19. A future Phase-20 step would only be justified if one of the following is true:

Discipline note

We chose to lock at Phase 19 with the baseline-comparison finding visible rather than to suppress it or tune it away. The goal of this site is to make the corporate evidence chain available with its limits intact, not to advertise a stronger conclusion than the data supports.