AN-018: Gate D4 — CADE winner-heavy diagnostic¶
Intuition (plain-language)
Why is the screen blind to ringleaders? D4 measures it directly: only ~15% of direct CADE defendants are always-losers, and their median win rate (0.261) is triple the cobidders' (0.086). Ringleaders are winner-heavy by construction — capturing contracts is the whole point of running the cartel. A screen built on persistent losing therefore cannot cover them, and shouldn't be asked to. This is the mechanism behind the AN-007 null.
Question¶
D4 gate diagnostic: what share of direct CADE defendants are always- losers, and what is their win-rate distribution? The diagnostic mechanistically confirms the predicted AUC null against direct defendants (AN-007).
Design¶
- Sample: 47 direct CADE defendants linked to BEC.
- Comparison set: 193 cobidders.
- Outcomes:
- share of always-losers among direct defendants;
- median win_rate (direct defendants vs cobidders);
- median win count.
- Test: Mann–Whitney on win_rate distributions.
Results¶
| Quantity | Direct defendants | Cobidders |
|---|---|---|
| N | 47 | 193 |
| Share that are always-losers | 14.9% (7/47) | 100% (193/193) |
| Median win rate | 0.261 | 0.086 |
| Median win count | 42 | (always-losers ⇒ 0 wins) |
Macros: \valDirectCADE, \valDirectShareAL (14.9), \valDirectMedWR
(0.261), \valOthersMedWR (0.086), \valDirectMedWins (42),
\valCobidders.
Mann–Whitney test on win_rate (direct defendants vs cobidders): p < 0.05.
Figure: direct CADE defendants vs cobidders on two dimensions — median win rate (red, left axis) and % always-losers (navy, right axis). Direct defendants: win rate 0.261, 14.9% always-losers. Cobidders: win rate 0.086, 100% always-losers by construction. The loser-side rank literally cannot cover most direct defendants.
Interpretation¶
D4 passes. Direct CADE defendants are structurally winner-heavy: only 14.9% are always-losers, and their median win rate (0.261) is ~3× that of cobidders (0.086). A loser-side rank built from always- loser participation literally cannot cover most of them, by construction.
This mechanistically explains the predicted null AUC against direct defendants (AN-007): the scope of the screen is loser-side adjacency, not membership.
D4 closes the four-diagnostic gate battery (D1–D4) from 2026-04-30. The result is load-bearing for the framing of §4.3 of the manuscript: direct-defendant AUC ≈ 0.50 is a feature of the scope, not a failure of the screen.
Follow-ups¶
- Decomposition by adjudication date (within-cartel role allocation).
- Sensitivity to alternative direct-defendant definitions.
- Triangulation with the unified mechanism quadrants (AN-024).
