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Award-layer gatekeeping cuts the bid-microdata pool by 83%

Intuition (plain-language)

This is the whole point, stated as a budget. Forensic bid analysis is costly, so you cannot run it on every firm. Route it instead through the top of the cheap loser-side ranking: you open expensive bid microdata for only ~17% of firms and still recover about two-thirds of the known cartel-linked losers. The screen earns its keep not by catching everyone, but by telling an enforcer where to spend the forensic budget first.

🟡 Used as a gatekeeper, the FL14 ranking cuts the bid-microdata pool required for the forensic stage by 83% while still recovering 131 of 193 adjudicated cobidders (68%). This is the cost-of-evidence headline of the paper: the award layer pays for itself by triaging where costly bid recovery should begin.

The in-sample operational metrics: precision@500 = 0.132 (lift 11.5×), precision@1000 = 0.097 (lift 8.5×), recall@1000 = 50% (AN-012).

Under temporal-holdout discipline (the operationally honest column): precision@500 = 0.070 (lift 6.1×, retention 53%), precision@1000 = 0.066 (retention 68%); recall@500 = 18%, recall@1000 = 34% (AN-013).

The gatekeeping arithmetic is the operational architecture relevant for agencies that cannot afford to open the bid layer for every firm. The joint-scoring upper bound from AN-010 (AUC 0.955) is the full-observability counterfactual that gatekeeping approximates at lower cost.

Caveat. Recovery and pool-reduction numbers are in-sample; the operational reading uses the temporal-holdout precision@k (AN-013), which retains roughly half the in-sample lift. The 83% pool cut is robust (it is a property of the ranking + cutoff, not of the evaluation regime); the precision claim is calibrated against the audited column.

The reading is 🟡 pending independent replication on a non-BEC procurement panel.

Sources.

  • Own analysis: AN-012 (in-sample precision@k), AN-013 (temporal- holdout audit), AN-014 (leakage audit — defensible verdict), AN-034 (sequential envelope — 74% joint recall at 17% microdata), AN-035 (full architecture × k × regime matrix — sequential K=2,000 beats joint in temporal holdout), AN-036 (K-fold CV precision SD ≤ 0.011).
  • Cross-refs: H:gatekeeping-cost-of-evidence; docs/results.md.
  • Macros: \valFL (2,735 firms above cutoff), \valCobidders (193), \valPrecInSFivehu (0.132 in-sample), \valPrecTHFivehu (0.070 temporal), \valLiftTHFivehu (6.1×), \valOpRetentionFiveHund (53%), \valOpFlaggedFiveHund (35 cobidders flagged in top-500 temporal holdout).
  • Validation: backing scripts scripts/42_operational_metrics.R, scripts/43_precision_at_k_audit.R, scripts/40_leakage_audit_d3.R.