Final Validation Report: Competitive Auctions and Digital Goods

Updated: 2026-09-09

1. Human Verdict

The selected auction revenue and truthfulness results are formalized.

2. Closeout Status

3. Source and Scope

Goldberg, Hartline, and Wright, Competitive Auctions and Digital Goods. The public preliminary paper supplies the theorem numbering and selected auction models and results. Lemma 8.1 and Theorem 8.2 use the later journal version’s monotone-offer condition, explained in the source note. The eight unnumbered Section 11 claims are outside the selected named-theory scope.

4. Researcher Summary of Checked Results

Result Comparison with source
Theorem 4.1; Corollary 4.2; Theorems 7.1–7.2 Exact asymptotic bounds with domain clarification. The finite logarithmic bounds use largest normalized bid h≥2h\geq2 and, for the count bound, at least two bidders.
Lemma 6.1 Exact.
Exact-half sampling; bounded dual-price mechanism Exact with parity clarification. Round half-sizes down for odd inputs; truthfulness and supply feasibility hold for all natural inputs, with exact halves for even inputs.
Theorem 6.2 Exact with count-parameter clarification. The winner-count parameter α\alpha is a natural number; the stated probability and revenue bounds are proved for uniform half-sampling.
Lemma 8.1 Exact with the journal’s monotonicity condition. Allocation probability increases with the bid under the journal’s cross-bidder offer condition.
Theorem 8.2 Exact with the journal’s monotonicity condition. Expected revenue is at most the optimal fixed-price revenue, including arbitrary real offer distributions.
Theorem 9.1 Exact asymptotic conclusion with source clarification. Integer high-bid examples have R/F≤1/HR/F\leq1/H and F≥αHF\geq\alpha H, ruling out a constant competitive ratio for deterministic bid-independent auctions.
Lemma 9.2 Exact.
Theorem 9.3 Exact asymptotic conclusion with source clarification. The same impossibility holds for every truthful deterministic auction in the paper’s set-of-bids model.
Bounded-supply rejection Exact with a selection-rule clarification. If demand exceeds supply, serve accepting bidders in a fixed order independent of their bids.

5. Remaining Boundaries and Gaps

None for the selected named-theory results. The eight unnumbered Section 11 claims remain outside that scope.

6. Additional Assumptions Beyond Paper

Lemma 8.1 and Theorem 8.2 use the journal monotonicity condition described in Section 10.

7. Proof-Strategy Deviations

The journal’s inverse-CDF construction is read as the lower generalized inverse, which handles jumps in the offer distribution. The source note explains why this preserves the marginals and revenue argument.

8. Proof Tricks Worth Reusing

Couple different offer distributions using one uniform random variable to compare their total expected revenue with a fixed-price benchmark.

9. Generalizations, Conjectures, and Extensions

The formalization additionally proves explicit finite bounds for the asymptotic results.

10. Source Clarifications and Exact Readings

The memo gives the logarithmic domains, journal monotonicity condition, count and parity conventions, and integer examples for the impossibility results.

The concrete randomized mechanisms use finite distributions; the general auction model allows countable distributions. Theorem 8.2 separately covers arbitrary real offer distributions. The bounded dual-price competitive guarantee is conditional on the stated sampling good-event bounds; the parity convention alone supplies no new odd-input revenue guarantee.

11. Paper Issues or Caveats

The journal condition narrows the preliminary version’s claim about all truthful auctions; see Section 10. The remaining notes clarify domains and conventions.

12. Detailed Formalization Evidence

PaperInterface.lean states the selected results and ProofInterface.lean supplies their proofs. The selected surface contains 37 model and definition items and 12 result contracts.

13. Paper Assumption Provenance

The assumption ledger records the eight paper conditions listed in status.json, including the journal monotone-offer condition.

14. Displayed Formula Provenance

The statement map links revenue, benchmark, sampling, and bounded-supply formulas to their source passages and formal statements.

15. Library Lift Pass

The real-distribution inverse-CDF argument supplies reusable probability results. Auction benchmarks and source-specific mechanisms remain paper-local.

16. DAG Audit

The dependency diagram, generated from its source, shows how the auction model and benchmarks support the revenue, sampling, and deterministic lower bounds. It was rendered and visually checked on 2026-09-08.

17. Validation Checks

The focused-build receipt, import-closure receipt, and closeout record record validation for their pinned mathematical inputs.

18. Paper Definitions Checked

Checked definitions cover auction outcomes, truthfulness, bidder profit, revenue and benchmarks, bid-independent and sampling mechanisms, and unlimited- and bounded-supply models. The statement map records their source connections.

19. Named Theorem Statements Checked

Section 4 lists the selected named results using the preliminary paper’s numbering. The grouped first row covers the logarithmic revenue bounds; Theorem 7.2 includes both the guarantee and its tightness construction.

20. Paper-Facing Statement Validator Ledger

The source-to-statement review contains six direct matches and six corrected-target matches for the 12 result contracts. The paper-model review contains 73 prerequisite judgments. Their reader-facing interpretation is summarized in Section 4.

21. Source-Coverage Audit Ledger

The 59-entry statement map contains 49 selected source items, eight unnumbered Section 11 claims outside the selected scope, and two proof-support entries.