{"id":"9d9ff2dc-c72f-4c54-8db2-d8ebed4c8cd4","arxiv_id":"2607.11240","paper_version":1,"verdict":"CONDITIONAL","confidence":"HIGH","novelty_score":7.0,"correctness_risk":"medium","formal_verification":"none","parameter_count":5,"one_line_summary":"ePBS's ex-post stop-and-disclose flexibility creates a ratchet that shades early bids and opens revenue-efficiency valleys; limited TEE commitment recovers about 25% revenue over first-price in finite grids.","lead":"Ethereum's move from relay-mediated PBS to protocol-facing ePBS lets proposers wait and reuse early bids as signals, which makes builders shade and pool those bids. The paper shows this ratchet cuts revenue and efficiency, then designs a TEE sidecar that recovers roughly a quarter of the lost proposer revenue in finite benchmarks.","discovery_kind":"new_application","skeptic_critique":{"model":"grok-4.5","headline":"The ~25% TEE revenue claim is a best-found nonconvex finite-grid number under report-cap restrictions, not a certified optimum; that is the load-bearing soft spot for the quantitative half of the central claim.","rationale":"The reader correctly separates a solid qualitative mechanism (ratchet under limited commitment; Myerson under full commitment) from a fragile quantitative TEE number. That is the right load-bearing concern: the analytical and calibrated ratchet evidence would still stand if the 25% figure moved, but the abstract and strongest claim package both together. No internal inconsistency appears in the PBE constructions or the Myerson reduction; the soft spot is numerical certification and external validity of the finite TEE program. A multi-start / bound check on the exact computational object the paper already defines would settle whether the concern lands without requiring new theory. Verdict remains CONDITIONAL; no upgrade to ACCEPT is warranted until the TEE optimum is better certified, and no downgrade to REJECT is warranted because the qualitative core is independently supported.","tokens_in":61821,"tokens_out":590,"duration_ms":6353,"concrete_test":"Re-solve the report-capped program of App. G.5 on the same 5×5 Uniform/k2 sweep with multiple random starts and a global nonconvex solver (or a certified branch-and-bound bound); if the best-found Rev/FPA ratio falls below ~1.10 or the duality gap exceeds 10% of FPA revenue, the headline ~25% claim is not robust even inside the paper’s restricted computational benchmark.","verdict_should_be":"CONDITIONAL","load_bearing_attack":"The qualitative ratchet story is well supported: Thm 2 constructs uni-pooling PBEs with revenue-efficiency valleys under endogenous stopping, Prop 6 shows full commitment collapses to Myerson, and the CFR+ calibration in §5 produces the same valley pattern under non-i.i.d. values and private disclosure. The quantitative half of the strongest claim—that limited TEE commitment recovers ~25% proposer revenue over FPA—rests on a different footing. Thm 3 reduces the exact fast-fast design to a nonconvex MI-QCQP; App. G.5 then imposes a report-cap and a no-overbidding deviation domain for computation, and §6.4 evaluates best-found solutions on a 5×5 grid, explicitly noting that the program is NP-hard and that the numbers are not certificates for the exact program. If those local solutions are far from global, or if the 5×5 grid and report-cap materially change the optimum, the ~25% figure does not transfer and the mitigation claim weakens from a measured gain to a directional illustration.","agreement_with_reader":"agree"},"referee_report":{"model":"grok-4.5","summary":"The paper models Ethereum block building under PBS and ePBS as restrictions of a common imperfect-information two-stage auction with verifiable messages and latency-asymmetric information updates. PBS has exogenous stopping and full public disclosure; ePBS endogenizes stopping and disclosure after signed stage-1 bids, at the cost of lower canonicalization probability k2. Analytically, separating PBS PBEs preserve FPA interim payoffs when q1 is large enough (Lemma 1, Theorem 1) and are ruled out when q1 is too small (Proposition 4). In simplified two-fast-builder ePBS, the paper constructs a family of uni-pooling PBEs (Theorem 2) in which builders pool or shade early bids because the proposer can defer and exploit the bid history—a ratchet effect that can produce revenue and efficiency valleys relative to FPA. Full commitment collapses to static Myerson (Proposition 6). A TEE sidecar is proposed as limited commitment to stopping/disclosure while preserving pay-as-bid; the design is reduced to a bilinear/MI-QCQP program, and best-found solutions on a 5×5 grid raise proposer revenue by roughly 25% over FPA. Calibrated CFR+ (EFCCE) runs with Titan–BuilderNet values reproduce FPA-like PBS behavior and an ePBS revenue-efficiency valley.","tokens_in":62147,"tokens_out":1644,"duration_ms":27541,"significance":"If the qualitative results hold, the paper makes a clear contribution to blockchain market microstructure and limited-commitment auction design: it isolates how enshrining PBS shifts the proposer from a passive auctioneer to a sequential information designer, and it links that shift to a ratchet distortion rather than a pure latency race. The analytical PBS and simplified-ePBS characterizations are carefully scoped (regular pure class, regular bang-bang class, explicit cutoff admissibility CF(k2)), with full appendix proofs and envelope/rank-space arguments that are standard and checkable. The calibration is honestly labeled as approximate EFCCE rather than PBE and is grounded in relay traces, which strengthens external validity of the valley pattern. The TEE formulation as constrained information design under native pay-as-bid is a useful protocol-facing mitigation idea. The main significance risk is quantitative overclaim on the TEE gain: the ~25% figure is a best-found nonconvex finite-grid number under report-cap restrictions, not a certified optimum, so the mitigation half of the abstract is currently weaker than the ratchet diagnosis.","major_comments":[{"comment":"Abstract and §6.4 (also Theorem 3, Appendix G.5): The abstract states that the TEE design increases proposer revenue by approximately 25% relative to FPA. The body evaluates a report-capped, no-overbidding-domain computational program on a 5×5 value–bid grid and explicitly notes that the exact problem is a nonconvex MI-QCQP (NP-hard) and that reported numbers are best-found outcomes for a restricted benchmark, not certificates for the exact program. That gap is load-bearing for the mitigation half of the central claim. Either (i) strengthen the computation (larger grids, multiple starts with optimality gaps, or a tractable policy class with certified bounds) or (ii) rephrase the abstract and evaluation as a directional finite-grid illustration with the report-cap and non-global-optimality caveats stated up front.","section":null},{"comment":"Definition 5 and Theorem 2 (Section 4.3): The uni-pooling ratchet is proved only in simplified ePBS, where the proposer may only stop or fully broadcast—no selective private disclosure. Full ePBS (Definition 2) and the calibrated game allow private/targeted disclosure, which is exactly the channel highlighted in Figure 8. The paper needs a tighter argument that the simplified construction is not an artifact of forbidding selective disclosure: either extend the analytical ratchet to a nontrivial selective-disclosure class, or give a formal reduction/robustness statement explaining why full-broadcast uni-pooling still identifies the same force that appears under private disclosure in §5.","section":null},{"comment":"Section 6.1–6.2 and Figure 9: Proposition 6 shows full commitment implements static Myerson at stage 1, while the TEE is deliberately limited to stop/message commitment under native pay-as-bid. The institutional discussion notes that full Myerson may require a proxy that recreates relay-like intermediation—the problem ePBS was meant to reduce. The manuscript should make the welfare/centralization trade-off quantitative or at least sharper: under what conditions does limited TEE commitment dominate both uncommitted ePBS and proxy-Myerson once proxy concentration, liveness, and key-custody risks are counted, rather than treating TEE as an unambiguous leveling device.","section":null},{"comment":"Section 5.1–5.2 and Appendix A: The calibrated valley is the main external-validity support for the ratchet outside the two-builder i.i.d. theory. CFR+ yields approximate EFCCE, which the paper correctly distinguishes from PBE, but the interpretation still treats stage-1 IR/BV declines and stop/disclose heatmaps as evidence of the same strategic channel as Theorem 2. Please add a short robustness check or diagnostic that the valley is not driven by coarse correlation alone (e.g., comparison to pure-strategy best-response dynamics, or restricted strategy spaces that force independent play), so the computational pattern can be read as corroboration rather than a weaker equilibrium class with different incentives.","section":null}],"minor_comments":[{"comment":"Figure 6–8 captions and §5.2: State units (mETH) and the exact latency profile labels consistently in every panel; some panels refer to Titan/BuilderNet while others use B1/B2 without a legend mapping.","section":null},{"comment":"Proposition 3: The non-overbidding convention for stage-2 bids is introduced for the threshold claims but is not part of the baseline bid space in Section 3; flag this modeling choice earlier when the bid space is defined.","section":null},{"comment":"Appendix B.1: The 100ms response-window censoring assumption for loser values is identifying; a one-paragraph sensitivity note (e.g., δ ∈ {50,100,200}ms) would help readers assess the joint log-normal fit.","section":null},{"comment":"Notation: k⋆2(βFPA), CF(k2), and K+F appear in multiple sections; a short notation table would reduce cross-reference friction.","section":null},{"comment":"Related work: Concurrent competing-auctions work [41] is discussed; a slightly sharper one-paragraph contrast on sealed FPA vs endogenous timing/disclosure would help position the contribution for non-specialists.","section":null},{"comment":"Typos/consistency: “Respctively” in Figure 8 caption; occasional “Glamsterdam” roadmap dating; ensure arXiv subject and JEL codes match the final framing.","section":null}],"recommendation":"major_revision","confidential_remarks":"The qualitative ratchet diagnosis is the publishable core and is stronger than the TEE percentage. I would not reject on the computational soft spot alone, but I would not accept with the abstract’s ~25% claim as currently written. If the authors demote the TEE number to a clearly caveated illustration and tighten the simplified-vs-full ePBS link, this could become a solid contribution for a theory/microstructure venue. Scope fit is good for cs.GT / market-design audiences; less so if the journal expects certified mechanism-design optima rather than protocol-facing limited-commitment designs."},"author_rebuttal":null,"desk_editor":{"model":"grok-4.5","letter":"The thing worth knowing is that this is a real mechanism-design account of how enshrining PBS changes incentives. Endogenous stop-and-disclose after signed early bids turns those bids into signals; builders shade and pool; you get revenue-efficiency valleys. That ratchet is not hand-waved.\n\nWhat is new is the common two-stage game with verifiable messages and asymmetric latency updates, then PBS vs ePBS as restrictions of it. For PBS they get clean separating results: FPA payoff equivalence, existence when q1 ≥ 1/2, nonexistence when q1 < 1/n (stronger for uniform). For simplified ePBS they construct a global uni-pooling family with an explicit cutoff correspondence and show the valleys analytically. Full commitment collapses to Myerson, which is the right benchmark. The CFR+ calibration is honestly labeled EFCCE, uses real Titan–BuilderNet traces, and reproduces the same valley under non-i.i.d. values and private disclosure. Citation pattern is good; concurrent competing-auctions work is positioned fairly as complementary.\n\nSoft spot is the quantitative TEE claim, and only that. The exact design is a nonconvex MI-QCQP; they then report best-found solutions on a 5×5 report-capped grid and say plainly these are not certificates for the exact program. So the ~25% over FPA is a directional finite-benchmark number, not a transferable optimum. Theory and calibration still stand without it. Code/data are not shipped, which is a minor reproducibility ding for the numerical half.\n\nThis is for people who care about blockchain market microstructure or auctions with limited commitment. The qualitative story is strong enough that a serious editor should send it to referees; the TEE section will get pushed to be more careful about what is proved vs illustrated. I would engage with it and cite the ratchet and the PBS separating conditions.","headline":"Solid limited-commitment auction paper on ePBS: the ratchet is real and carefully proved; the ~25% TEE number is a best-found finite-grid illustration, not a certificate.","tokens_in":62826,"tokens_out":482,"would_cite":true,"duration_ms":7890,"reading_group":"yes","serious_thinker":"yes","would_accept_peer_review":true},"rs_alignment":null,"lean_confirmation":null,"pith_extraction":{"msc":[],"pacs":[],"model":"grok-4.5","headline":"ePBS lets proposers wait and reuse early bids, so builders shade and pool them, creating revenue and efficiency valleys that limited TEE commitment can partly reverse.","keywords":["ePBS","proposer-builder separation","block building","ratchet effect","first-price auction","limited commitment","TEE mechanism design","latency heterogeneity"],"falsifier":"On the paper's own calibrated Titan-BuilderNet game, if raising continuation reliability k2 through the intermediate range does not produce a joint drop in proposer revenue and allocation efficiency under no-regret play, or if a TEE-style committed stop-and-disclose policy fails to raise revenue above the first-price line by a material amount on that same grid, the central mechanism claim fails.","tokens_in":62647,"feed_emoji":"⛓️","tokens_out":900,"duration_ms":11298,"temperature":0.7,"pith_summary":"Ethereum is moving from relay-mediated proposer-builder separation (PBS) to enshrined ePBS, where builders bid directly to proposers and proposers choose when to stop and what bid history to reveal. The paper models both as versions of one two-stage auction in which an early bid is both a payment offer and a verifiable signal. Under PBS, exogenous stopping can still support separating first-price-like outcomes when stage-1 settlement is likely enough. Under ePBS, the proposer's ability to defer after seeing signed bids creates a ratchet: builders expect early information to be used against them later, so they shade or pool early bids. Exact equilibria in a simplified two-builder case and calibrated no-regret play on real builder values both show resulting revenue and allocation valleys. Full commitment would collapse to a static Myerson auction and remove the distortion; a TEE sidecar that commits only to stopping and disclosure recovers roughly a quarter more proposer revenue than the first-price benchmark in conservative finite designs.","feed_headline":"ePBS bids become signals, so builders shade and revenue valleys form","feed_subtitle":"Limited TEE commitment recovers about 25% more proposer revenue than first-price in finite tests","key_machinery":"The ratchet channel in the two-stage block-building game: an early signed bid is both a pay-as-bid offer and a verifiable signal the uncommitted ePBS proposer can exploit by deferring and disclosing, which induces uni-pooling perfect Bayesian equilibria (low types pool at zero, high types separate) and the same defensive pattern in calibrated no-regret play.","core_discovery":"When the proposer can choose to defer after observing signed stage-1 bids and then use that history to intensify stage-2 competition, builders anticipate extraction and shade or pool early bids, producing allocation inefficiency and revenue-efficiency valleys relative to the first-price benchmark. Full commitment restores the static Myerson auction; limited TEE commitment to stopping and disclosure recovers about 25% more proposer revenue than first-price in the paper's finite benchmarks.","pith_inferences":["If solo proposers cannot access TEEs or reputation, the ratchet may reintroduce centralization pressure even after relays are enshrined away.","The same stop-and-disclose ratchet logic would apply to other short-horizon auctions with verifiable early messages and optional continuation (for example, some MEV or batch-settlement designs).","A sharper continuous characterization of when latency premia survive endogenous disclosure would be the natural next theory step beyond the paper's simplified uni-pooling and finite TEE programs."],"forward_implications":["Relay-mediated PBS with exogenous stopping can retain first-price payoffs under separating equilibria when stage-1 settlement is sufficiently likely; ePBS does not automatically inherit that property.","ePBS compresses but does not eliminate fast-builder latency premia while adding a commitment-access gap that favors institutional proposers over solo validators.","A TEE sidecar that commits only to stopping and disclosure, without rewriting the native pay-as-bid rule, is a protocol-facing way to capture part of the full-commitment Myerson gain.","Protocol design that leaves stopping and disclosure fully ex post will induce defensive early pooling once continuation becomes credible."],"fun_headline_variants":["ePBS early bids become signals that builders shade or pool","Ratchet effect: proposer deferral makes ePBS builders shade bids","ePBS commitment failure yields allocation gaps and revenue valleys","Builders pool stage-1 ePBS bids fearing ex-post extraction","TEE limited commitment lifts ePBS revenue ~25% over first-price"],"cache_read_input_tokens":49280,"weakest_assumption_plain":"The roughly 25% TEE revenue gain is a best-found result from a restricted nonconvex program on a small discrete bid-value grid, not a proven global optimum that is known to hold for continuous or larger markets.","fun_headline_variants_meta":{"raw":{"variants":["ePBS early bids become signals that builders shade or pool","Ratchet effect: proposer deferral makes ePBS builders shade bids","ePBS commitment failure yields allocation gaps and revenue valleys","Builders pool stage-1 ePBS bids fearing ex-post extraction","TEE limited commitment lifts ePBS revenue ~25% over first-price"]},"model":"grok-4.5","effort":"low","cost_usd":0.005176,"raw_usage":{"total_tokens":1502,"prompt_tokens":863,"num_sources_used":0,"completion_tokens":90,"cost_in_usd_ticks":51760000,"prompt_tokens_details":{"text_tokens":863,"audio_tokens":0,"image_tokens":0,"cached_tokens":256},"completion_tokens_details":{"audio_tokens":0,"reasoning_tokens":549,"accepted_prediction_tokens":0,"rejected_prediction_tokens":0}},"tokens_in":863,"tokens_out":90,"duration_ms":6753,"temperature":1.0,"reasoning_tokens":549,"cache_read_input_tokens":256,"cache_creation_input_tokens":0},"cache_creation_input_tokens":0},"created_at":"2026-07-14T06:04:08.676123+00:00","model_set":{"reader":"grok-4.5"},"falsifier":"On the paper's own calibrated Titan-BuilderNet game, if raising continuation reliability k2 through the intermediate range does not produce a joint drop in proposer revenue and allocation efficiency under no-regret play, or if a TEE-style committed stop-and-disclose policy fails to raise revenue above the first-price line by a material amount on that same grid, the central mechanism claim fails.","supporting_citations":[],"review_version":1}