Tools chosen: kalshi_direct kalshi_related fred code_execution claude_news polymarket_related

Sub-questions (Fermi decomposition)

Planner reasoning

This is a very long-horizon macro question (2031 annual real GDP growth in a 0.4pp-wide bucket), so the dominant inputs are (a) the Kalshi market's own price across the full bucket ladder, and (b) the historical distribution of US annual real GDP growth plus official long-run projections (CBO, Fed SEP longer-run ~1.8-2.0%). I'll anchor on the direct market, pull the sibling buckets for the implied distribution, get the historical annual growth series from FRED, and compute a base-rate/normal-fit probability for the 2.1-2.5% bin.

# Event US real GDP growth in 2031 falls between 2.1% and 2.5% (BEA annual average, YoY) — Kalshi ticker KXGDPYEAR-31-B2.3. # Outcomes to forecast - Yes (2031 real GDP growth in [2.1%, 2.5%]) - No (2031 real GDP growth outside that range) # Kalshi market anchor Current YES price: **15%** (up sharply from 5% low; +10pp in 7 days, +4pp in 30 days). Avg daily volume ~1,306 contracts over 8 data points — moderate liquidity, recent momentum upward but market still young/thin (only 8 days of data), suggesting price discovery is unstable and possibly noisy. # Sub-question answers 1. **Kalshi sibling buckets / implied distribution** — Only two sibling series retrieved (KXGDPYEAR-36 and -35), not full -31 ladder. KXGDPYEAR-36-B2.8 (2.6-3.0%) trades at 10%; KXGDPYEAR-35-B1.8 (1.6-2.0%) trades at 14%. This shows Kalshi consensus is spread across multiple buckets with no single dominant mode >20%, consistent with wide uncertainty this far out (2031 close date is 2032). [kalshi_related] 2. **Historical frequency of 2.1-2.5% band** — Empirical: 8/75 years (1950-2024) = 10.7%; 5/40 years (1985-2024) = 12.5%. Normal-distribution fits (varying mean/sd assumptions) give 8%-13%, central ~10-11%. [code_execution] 3. **Official long-run projections** — CBO (Feb 2026): potential GDP growth averages 1.8%/yr for 2031-2036 (down from 2.1% in 2026-2030); actual 2031 growth likely ~1.8%. Fed SEP longer-run median: 1.8% (central tendency 1.6-1.8%), stable across 2025-2026 rounds. Blue Chip consensus: 1.9% for 2025-29. IMF WEO: US settling near 2.0-2.1%. All cluster **below or at the low edge** of the 2.1-2.5% Yes range. [claude_news] 4. **Dispersion of annual growth** — Full-sample (1950-2024) sd ≈2.31pp; recent era (1985-2024) sd ≈1.69pp. A 0.4pp-wide bin captures at most ~10-13% of mass even under favorable (low-mean-adjacent, low-sd) assumptions. [code_execution] 5. **Resolution definition sensitivity** — Rules text unspecified beyond "real GDP growth in 2031"; presumably BEA Q4/Q4 or annual-average release (likely first annual estimate, ~Jan/Feb 2032, before close 2032-02-29). No first-vs-revised distinction found in research; this is a live gap. 6. **Structural shifts (AI, immigration, tariffs, debt)** — Not directly addressed by news tool beyond noting CBO/Fed flag AI productivity as an upside risk to their below-2% baseline "though it's not far off." No quantified probability shift found; treated as unresolved upside tail risk only. # Key facts (high-confidence, factual) 1. [FRED A191RL1A225NBEA] Recent actual annual growth: 2025=2.1%, 2024=2.8%, 2023=2.9%, 2022=2.5%, 2021=6.2%, 2020=-2.1%. 2. [CBO Feb 2026] Potential GDP growth averages 1.8%/yr 2031-2036, down from 2.1%/yr 2026-2030, due to slower labor productivity growth. 3. [Fed SEP Dec 2025/June 2026] Longer-run median real GDP growth = 1.8%, central tendency 1.6-1.8%, stable. 4. [Blue Chip 2025] Medium-term (2025-29) consensus = 1.9%. 5. [Kalshi direct] YES price 15%, range 5-17% over 8 days, +10pp in past week. # Cross-market signals - Kalshi related: KXGDPYEAR-36-B2.8 (2.6-3.0%, 2036) = 10%; KXGDPYEAR-35-B1.8 (1.6-2.0%, 2035) = 14% — both near-neighbor buckets trade similarly to or below the 2031 B2.3 bucket, suggesting no strong single-year consensus mode. - Polymarket: No matching markets found (0/100 scanned). - Sportsbook implied: N/A (not applicable to this event type). # Analyst opinions and speculation - Consensus institutional forecasts (CBO, Fed, Blue Chip, IMF) converge on 1.8-2.0% central estimate for 2031, placing it just below the Yes bucket's floor (2.1%). - AI-driven productivity is cited by CBO/Fed as a plausible upside risk that could push growth into or above the 2.1-2.5% range, but not quantified. - Historical base rates (10.7-12.5%) are broadly consistent with — slightly above — what a normal distribution centered at 1.8-2.0% with realistic sd (1.7-2.3pp) would imply for this bucket (~9-11%), given the bucket sits adjacent to but above the modal forecast. # Directional lean per outcome - **Yes (2.1-2.5%)**: Supporting — historical base rate ~10-13%; 2025 actual already printed 2.1% (bucket floor), showing recent proximity; wide sd could still deliver upside surprise (AI productivity). Opposing — every major institutional forecast (CBO, Fed, Blue Chip, IMF) centers 2031 growth at 1.8-2.0%, below the bucket; CBO explicitly models labor-productivity slowdown through 2031-2036. - **No**: Supporting — strong structural consensus (CBO/Fed/Blue Chip/IMF) all point below 2.1%, and slower labor force growth is a well-documented multi-vintage CBO finding; historical base rate for this specific band is inherently low (~10%) even absent directional bias. Opposing — Kalshi's own price (15%) is running above the ~10-11% historical/model-implied rate, and recent momentum (+10pp in 7 days) may reflect newer information not fully captured in research. # Gaps / unknowns - Full KXGDPYEAR-31 bucket ladder not retrieved — can't confirm total probability mass sums to 100% or locate the modal bucket precisely. - Exact resolution source (BEA vintage: advance/second/annual, Q4/Q4 vs annual average) unconfirmed from rules text. - No Polymarket cross-check available. - Reason for Kalshi's recent +10pp week-over-week jump not identified (news-driven vs thin-volume noise). # Calibration anchors - Kalshi current YES price: **15%** (anchor). - Historical empirical base rate for this bin: ~10.7% (1950-2024), ~12.5% (1985-2024). - Model-based (normal distribution, plausible mean/sd) range: ~8-13%, central ~10-11%. - Institutional consensus mean (1.8-2.0%) sits just below bucket floor, arguing for a probability at or below the historical base rate rather than above Kalshi's current 15%.

1. Both forecasters converge almost identically (13% and 12%) despite claiming independent analysis — this is a red flag for shared anchoring rather than genuine independent triangulation; neither explores why Kalshi's own adjacent-bucket pricing (2.6-3.0%=10%, 1.6-2.0%=14%) implies the 2.1-2.5% bucket (15%) is priced *above* both neighbors even though institutional consensus (1.8-2.0%) should favor the lower bucket as modal — this inconsistency in the cross-market data is never addressed. 2. Both dismiss the +10pp weekly Kalshi jump as likely "noise" from thin liquidity, but neither considers the alternative that it could reflect a genuine catalyst (e.g., updated Fed/CBO commentary on AI productivity, a strong recent GDP print) that their news tools simply failed to surface — treating an unexplained signal as automatically discountable is itself an assumption, not a finding. 3. Neither forecast incorporates recession/tail-risk scenarios explicitly: 2031 is ~6 years out, and historical base rates (1950-2024) include multiple recession years with sharply negative growth — the brief's sd estimates already embed this, but neither rationale discusses how a plausible recession-then-rebound path could either compress or inflate the 2.1-2.5% bucket's probability differently than a stable-growth path would. 4. Sub-question 5 (resolution definition ambiguity — annual average vs Q4/Q4, first vs revised BEA vintage) is flagged as a "live gap" in the brief but is not incorporated into either forecast's uncertainty band; different vintages could shift the reported figure by several tenths of a point, which is material given the bucket is only 0.4pp wide. 5. Neither forecaster addresses sub-question 6's structural/policy risks (tariffs, immigration, debt dynamics) beyond a generic nod to "AI upside" — given 2031 sits several years into whatever administration is in power post-2028 election, policy-driven growth shocks (positive or negative) are a distinct unpriced tail that could push the actual number outside consensus-driven expectations in either direction. 6. Both forecasts settle just below Kalshi (12-13%) citing the base rate (10-13%) and institutional consensus (below 2.1%) as reasons to shade down, but neither seriously entertains that Kalshi's price could be informationally superior to static institutional projections (which are themselves stale, e.g., CBO Feb 2026 and Fed SEP figures may not reflect data closer to 2031); the near-uniform downward shift from 15% to ~12% may be under-weighting the market's information content.

13% (62% confidence)

Yes: 13% No: 87%

A 0.4pp-wide bucket against annual GDP growth with sd ~1.7-2.3pp can capture at most ~10-13% of probability mass, and the empirical frequency for this exact band is 10.7% (1950-2024) / 12.5% (1985-2024). Institutional consensus (CBO 1.8% potential, Fed SEP 1.8%, Blue Chip 1.9%, IMF ~2.0%) centers just below the bucket floor, which argues against pricing it above the raw base rate — though its adjacency to the modal forecast plus AI-productivity upside keeps it near the top of the model range rather than at the bottom. The Kalshi 15% anchor deserves respect (the critique is right that markets can hold information stale institutional projections lack), but with only 8 days of thin data, an unexplained +10pp move, and an incomplete ladder that may not sum to 100%, I shade modestly below it. The unresolved resolution-vintage ambiguity (annual-average vs Q4/Q4, first vs revised) adds noise that slightly diffuses probability away from any single narrow bucket. Final: 13% Yes, splitting the market anchor and the base-rate/model range.

Total pipeline time: 117.9s