Scan: GDP growth in 2036? — 2.6% to 3.0%

date	predicted	market price	confidence
2026-08-28	9%	10%	61%
2026-08-09	8%	7%	50%

1. Planner Fable 5.1 · Fermi decomposition + tool plan

Tools chosen: kalshi_direct kalshi_related fred claude_news code_execution polymarket_related

Sub-questions (Fermi decomposition)

What is the current Kalshi YES price for the 2.6-3.0% band in KXGDPYEAR-36, and does the full ladder of bands for 2036 (and sibling years 2026-2035) sum sensibly / imply a consistent distribution?
What is CBO's and the Fed's longer-run projection for US real potential GDP growth in the mid-2030s (e.g., CBO 2025 Long-Term Budget Outlook, FOMC longer-run SEP median)?
Historically (1950-2024, and separately 1990-2024), in what fraction of years did US annual-average real GDP growth fall between 2.6% and 3.0%?
What is the standard deviation of annual US real GDP growth around trend, and given a trend of ~1.8-2.2%, what probability does a normal/empirical distribution assign to the 2.6-3.0% band?
Is there credible evidence (e.g., AI-driven productivity forecasts, immigration/demographic scenarios) that would shift the mid-2030s trend growth toward 2.5-3.0%, and how much weight do mainstream forecasters give it?
How does Kalshi define 'GDP growth in 2036' (annual-average over prior year vs Q4/Q4), and does the band include or exclude endpoints and how is rounding handled?

Planner reasoning

This is an ultra-long-horizon question about a narrow 0.4pp band of US real GDP growth in 2036, so the forecast is dominated by base rates (historical distribution of annual growth) and long-run potential growth projections (CBO/Fed ~1.8%), plus any structural shifts (AI productivity, demographics). The Kalshi price is the anchor, but with such distant resolution, liquidity is likely thin, so cross-checking the full ladder of KXGDPYEAR bands and sibling years is important for calibration.

2. Research Parallel tool calls

tool	status	time	items	summary
kalshi_direct	OK	0.2s	1	## This Market's Kalshi Data 2.6% to 3.0% (KXGDPYEAR-36-B2.8) - Current price (probability): 9.00% - 7-day price change: +2.00% - 30-day price change: +3.00% - Average daily volume: 1108 contracts - Price range: 4.00% - 10.00% - Data points: 14 days
kalshi_related	OK	4.6s	3	3 related markets / summaries. series KXGDPYEAR: 0 markets (skipped 100 no-signal) \| keyword 'GDP growth 2036': ok \| keyword 'GDP growth 2035': ok \| keyword 'GDP growth 2030': ok
fred	OK	6.8s	6	Fetched 6 FRED series (lookback=27000d) (via search 'real potential GDP growth').
claude_news	OK	27.5s	9	Based on available research, here are the key findings: CBO Long-Term Projections (2036 & beyond) - CBO's February 2026 "Budget and Economic Outlook: 2026 to 2036" projects that real GDP grows by 2.2 percent in 2026 and then slows, averaging 1.8 percent per year from 2027 to 2036. https://ide
code_execution	OK	43.7s	0	## Findings Historical base rates (BEA real GDP growth, annual % change, hardcoded 1950–2024) - Full sample (1950–2024, n=75): 13/75 years in [2.6%, 3.0%] → 17.3%; mean = 3.19%, SD = 2.31 - Post-1990 (n=35): 10/35 → 28.6%; mean = 2.51%, SD = 1.74 - Post-2000 (n=25): 8/25 → *
polymarket_related	OK	4.6s	0	Scanned 100 active Polymarket markets, kept 0 matches. keyword 'GDP growth 2036': 0 markets \| keyword 'US GDP 2030': 0 markets \| keyword 'recession 2030': 0 markets

3. Evidence Brief Sonnet 5 · 5440 chars

# Event Kalshi market KXGDPYEAR-36-B2.8: resolves YES if US real GDP growth in 2036 falls between 2.6% and 3.0%. # Outcomes to forecast - Yes (2036 real GDP growth in 2.6%–3.0% band) - No (growth outside that band) # Kalshi market anchor Current YES price: **9%** (as of latest data). 7-day change: +2pp; 30-day change: +3pp. Price range over 14 observed days: 4%–10%. Average daily volume: 1,108 contracts (relatively active). Trend is drifting modestly upward but remains a low-probability outcome per the market. # Sub-question answers 1. **Kalshi ladder consistency** — B2.8 band priced at 9%. Sibling 2030 band (same 2.6-3.0% range, closer horizon) trades at 20%, and 2035's 1.6-2.0% band trades at 13% — suggesting the market assigns declining probability to higher-growth bands as horizon lengthens, consistent with mean-reversion to a lower long-run trend. No full ladder (all bands for 2036) was retrieved, so overall sum-to-100% consistency can't be confirmed. [kalshi_direct/kalshi_related] 2. **CBO/Fed long-run projections** — CBO (Feb 2026 outlook) projects real GDP averaging just 1.8%/yr 2027-2036, with 30-year average near 1.7%. FOMC longer-run median (June 2026 SEP) is 2.0%. Both are far below the 2.6-3.0% band. [claude_news/CBO, FOMC] 3. **Historical base rate** — 1950-2024: 13/75 years (17.3%) in band. Post-1990: 28.6%; post-2000: 32.0%; post-2010: 40.0% (band matched recent growth more often in the low-volatility 2010s). [code_execution] 4. **Distribution-based probability** — Using trend 1.8-2.5% and SD 1.5-2.3, normal-model P(2.6-3.0%) ≈ 8.8%-13%. Monte Carlo (trend~1.9%, SD~1.75%) gives ≈10.0%. [code_execution] 5. **AI/demographic upside** — No credible mainstream forecast found projecting mid-2030s trend growth into 2.5-3.0%; CBO's 95th-percentile decade-average scenario reaches only 2.6%, implying only a top-5% tail hits the low end of band. Blue Chip long-range consensus (2032-2036) spans just 1.7%-2.1%. [claude_news/CBO] 6. **Kalshi definition** — Exact methodology (annual-average vs Q4/Q4, rounding/endpoint treatment) not confirmed; official rulebook not retrieved. Likely BEA annual % change, chain-weighted (per series naming), but unverified. [claude_news — gap] # Key facts (high-confidence, factual) 1. [kalshi_direct] Current YES price for 2.6-3.0% band in 2036 = 9%; up from 4% low over past 14 days. 2. [claude_news/CBO] CBO Feb 2026 baseline: real GDP growth averages 1.8%/yr 2027-2036. 3. [claude_news/FOMC] Fed longer-run potential growth estimate = 2.0% (June 2026 SEP). 4. [FRED/GDPC1MDLR] Median longer-run real GDP projection stable at ~1.8-2.0% across 2023-2026 SEPs. 5. [code_execution] Historical base rate for landing in this exact band ranges 17%-40% depending on lookback window; recent decades trend higher due to compressed volatility. 6. [code_execution] Model-based (normal/Monte Carlo) estimates cluster at 9-13%, closely matching current Kalshi price of 9%. # Cross-market signals - Kalshi related: 2030 band (same range, shorter horizon) = 20% YES; 2035 band (lower range, 1.6-2.0%) = 13% YES — implies market sees 2036 growth distribution shifted lower/wider than nearer years, or simply reflects longer-horizon uncertainty discounting. - Polymarket: No matching markets found (0 relevant). - Sportsbook implied: N/A (not applicable to economic data market). # Analyst opinions and speculation - CBO's own sensitivity analysis: even 95th-percentile decade-average growth scenario only reaches 2.6%/yr — reinforces that hitting this band requires a materially above-consensus outcome. - Blue Chip Economic Indicators' most optimistic forecasters (top 10) average just 2.1%/yr for 2032-2036 — still below band floor. - No identified analyst commentary attributes a credible AI-driven productivity path to mid-30s trend growth in the 2.5-3.0% range; this remains speculative/unmodeled upside. # Directional lean per outcome - **Yes (2.6-3.0%)**: Supported by historical volatility (single-year growth can spike above trend even if trend is low, per post-2010 hit-rate of 40%) and by unmodeled AI-productivity upside tail. Opposed by uniform CBO/Fed consensus placing trend ~1.8-2.0%, CBO's own 95th-percentile tail only reaching 2.6%, and model-based estimates (9-13%) aligning with current market price. - **No**: Strongly favored — consensus institutional forecasts (CBO, Fed, Blue Chip) all project trend growth well below band, and quantitative/model synthesis converges near 9-13%, matching Kalshi's 9% price almost exactly. # Gaps / unknowns - Exact Kalshi settlement methodology (annual-avg vs Q4/Q4, rounding, endpoint inclusion) unconfirmed — could shift effective band width/probability slightly. - Full 2036 band ladder not retrieved, so cannot verify total probability sums to 100% (arbitrage check incomplete). - No explicit AI-productivity growth scenario forecasts found from major banks/think tanks specifically targeting 2036. # Calibration anchors - Kalshi current YES price: **9%** (anchor). - Model-based fair value estimate: ~9-13% (normal/Monte Carlo), closely bracketing market price — suggests market is reasonably efficient/well-calibrated here. - Historical base rate (full-sample 1950-2024): 17.3%; recent-decade (post-2010): 40% — wider historical range suggests some tail-risk of underpricing, but institutional forecasts strongly favor the lower model-based estimate over historical base rates given current trend deceleration.

4. Forecasters Fable 5.1 + GPT-5.6 Sol · in parallel

claude-fable-5-1

52% conf

Yes	12%
No	88%

Kalshi prices the 2.6-3.0% band for 2036 at 9%, and independent normal/Monte Carlo models using CBO/Fed trend (~1.8-2.0%) and historical single-year SD (~1.5-2.3) yield 9-13%, so the market appears roughly efficient. Institutional consensus (CBO 1.8% avg 2027-2036, FOMC 2.0% longer-run, Blue Chip 1.7-2.1%) sits well below the band floor, and even CBO's 95th-percentile decade scenario only reaches 2.6%. However, single-year growth is far more volatile than decade averages, the post-2010 hit rate for this band was 40%, and a 10-year horizon leaves room for unmodeled AI-productivity or cyclical upside, so I lean slightly above the market at 12%. Settlement methodology (annual vs Q4/Q4, rounding) is unconfirmed but unlikely to materially change the estimate.

gpt-5.6-sol

68% conf

Yes	10%
No	90%

The 9% Kalshi YES price is a strong anchor because relatively active trading and quantitative estimates of 9%–13% broadly agree. CBO, the Fed, and Blue Chip forecasts center long-run growth around 1.7%–2.1%, well below the 2.6%–3.0% band. Historical single-year volatility leaves a meaningful chance of landing in the band, supporting a slight move above the market price to 10%. The very long horizon and unconfirmed settlement methodology limit precision.

5. Devil's Advocate Sonnet 5 · red-team critique

Both forecasters cluster tightly around 9-12%, essentially anchoring on the model/market consensus without seriously engaging with the historical base-rate divergence — post-2010 hit rate was 40%, more than 3x their point estimates, and neither explains why decade-average trend deceleration should so thoroughly override single-year volatility evidence.

Neither forecast grapples with the cross-market inconsistency flagged in the brief: the 2030 band (same 2.6-3.0% range, shorter horizon) trades at 20% while 2036 trades at 9% — if anything, a longer horizon with unresolved AI-productivity uncertainty should arguably show a flatter or fatter-tailed distribution, not necessarily a monotonic decline to less than half the 2030 price; this discrepancy is not explored as a potential mispricing signal.

Both treat "10-year horizon uncertainty" and "AI-productivity upside" as decorative caveats added on top of the same 9-13% base rather than quantifying how much genuine tail-width should be added for a forecast 10+ years out with acknowledged model gaps (unconfirmed settlement methodology, no full ladder verification).

The brief notes the full 2036 ladder wasn't retrieved so sum-to-100% arbitrage can't be verified — neither forecaster flags this as a real risk to their point estimate's precision (e.g., if adjacent bands are underpriced/overpriced, 9-13% could be systematically biased).

Both forecasts move only 1-3pp above the current 9% price despite acknowledging a legitimate upside case (post-2010 40% base rate, unmodeled AI upside), suggesting anchoring bias — if the volatility/upside argument is taken seriously, the resulting shift should arguably be larger than a token 1-3 point nudge, or alternatively they should more explicitly justify why it's capped so low.

Neither forecast assigns meaningful weight to the settlement-methodology gap (annual-avg vs Q4/Q4) potentially widening or narrowing the effective band, despite both flagging it as unconfirmed — this is dismissed rather than incorporated into a wider confidence interval on the estimate itself.

6. Aggregator Fable 5.1 · final calibrated forecast

12% (60% confidence)

Yes: 12% No: 88%

Kalshi prices the 2036 2.6–3.0% band at 9%, and independent normal/Monte Carlo models built on the CBO/Fed trend (~1.8–2.0%) with historical single-year volatility land at roughly 9–13%, so market and models broadly agree. The critique's post-2010 40% hit rate is less compelling than it looks: that decade's trend was ~2.3%, placing the band near trend, whereas current institutional consensus (CBO 1.8%, FOMC 2.0%, Blue Chip 1.7–2.1%, CBO 95th-percentile only 2.6%) puts the band ~0.7pp above trend. However, the recession-skewed shape of annual growth (non-recession years cluster above the mean) and genuine trend uncertainty over a 10-year horizon justify a modest premium over the market, and the 2030 sibling at 20% hints the ladder may under-weight upside. I settle at 12%, at the upper end of both forecasters and the model range, with No at 88%.

Pipeline Timing

Total pipeline time: 136.3s

Per-tool research timings shown in the Research section above.