What we know about the limits of this data

What GAO has said

The Government Accountability Office has reported that approximately 70% of USAspending.gov information is inconsistent with program-level reporting, and that half of agencies with inconsistent data are not reporting at all. Reference: GAO blog post on USAspending.gov data quality.

What POGO has said

The Project On Government Oversight publishes “Ten Questions USAspending Can't Answer”, including limitations around sub-award visibility, contractor ownership obfuscation, and inconsistent set-aside reporting. We answer some of those questions (cost outlier patterns, contractor concentration, IDIQ task-order pricing); we do not answer others (sub-award accounting, bid rigging detection, cross-program portfolio analysis).

How we mitigate

• Frozen evidence. Each anomaly's comparison set is captured at flag time. Cohort medians drift; published claims do not.
• Ingestion run ledger. Every row in our database is stamped with the API call that produced it (source, query filters, timestamp). Reproducibility is built in.
• Deterministic confidence gate. Five rules. No human judgment in publication. Method version stamped on every flag.
• Right of reply rendered inline. Contractors get a printed mic on the same URL as the flag.
• 48-hour dispute SLA. Every dispute resolution is logged at /corrections.

Known issues with our data today

• ~40% of awards have phase=unknown. Our description-keyword classifier doesn't match the description text. These awards still score against the broader cohort but may have noisier signals.
• Detail enrichment is partial. The fields used for cost-growth and sole-source detection (cost_growth_ratio, extent_competed, parent IDIQ) are populated via a separate pass against /api/v2/awards/{id}. USAspending throttles this endpoint; the backfill runs nightly. Recently flagged awards may not yet have these fields populated.
• Federal grants are not indexed. Most IIJA highway dollars flow as grants to state DOTs, not direct contracts. Our IIJA-tagged subset is heavily concentrated in Federal Lands and DOD work as a result. Adding the grant-side ingester is a planned v2.
• SAM.gov enrichment is deferred. Contractor exclusions and parent-company linkage from SAM.gov would meaningfully improve the small-business-kingpin and shell-game patterns. Pending API-key application.