Tools chosen: kalshi_direct article_search claude_news kalshi_related polymarket_related code_execution

Sub-questions (Fermi decomposition)

Planner reasoning

planner fallback: broad sweep + category conditionals

# Current state Wild poliovirus (WPV1) remains endemic only in Afghanistan and Pakistan; as of late 2025 case counts are down year-over-year (38 by Oct 2025 vs 62 same period 2024) but no year since GPEI's 1988 launch has ever recorded zero global WPV1 cases. Resolution requires just ONE calendar year 2024–2029 with zero reported wild cases — not full certification (which needs 3 consecutive zero-years) — but persistent reservoirs, surveillance backlogs, and slipping "interruption" targets make even a single clean year uncertain. # Timeline of key events - 2021: Lowest-ever global WPV1 total, 6 cases (confirmed, historical record). - 2022–2024: Case counts rebounded — 30 (2022), 12 (2023), 99 (2024) — confirmed via WHO/GPEI reporting. - 2025-10-22: 38 WPV1 cases reported YTD globally (Afghanistan + Pakistan only), down from 62 in same period 2024 (confirmed, healthpolicy-watch.news). - 2025-10-12: Afghanistan-Pakistan land border closures disrupt AFP/environmental sample shipments to Islamabad reference lab, creating testing backlog (confirmed, WHO). - GPEI Action Plan (pre-2026): Original target to stop WPV1 transmission "no later than June 2026" (confirmed, GPEI Action Plan PDF). - 2026-03-04: WHO IHR Emergency Committee reports 2024 full-year total of 99 WPV1 cases; notes persistent high force of infection in core reservoirs (South KP, Karachi, Southern Afghanistan), funding cut 18% (confirmed, WHO statement). - 2026-04 (commentary): Reference to a revised "2027 target" for WPV1 eradication, implying the June-2026 goal has slipped (reported, CAGH-ACSM). - 2026 (mid-year, undated): TAG concludes interruption "remains achievable" but flags need for adjusted approach in Afghanistan's South region (reported, GPEI). - Ongoing: Forced repatriation of ~600,000 Afghan migrants from Pakistan, including ~200,000 unvaccinated children, cited as a fresh transmission risk (reported, news synthesis). # Event Will there be at least one calendar year between 2024 and 2029 with zero reported wild poliovirus (WPV1) cases globally? # Outcomes to forecast - Yes - No # Kalshi market anchor **KXPOLIOELIM-30 current YES price: 10.70%** (up +4.80% over 7 days, +0.40% over 30 days). Price range over 41 days of data: 4.30%–10.70%, average daily volume 282 contracts — thin but active market trending upward recently, likely reflecting the 2025 case-count decline (38 vs 62 YoY). # Sub-question answers 1. **Current Kalshi price?** — 10.70% YES, up sharply (+4.8pp) in the past week; this is the sole listing (kalshi_direct, kalshi_related). 2. **Recent news affecting outcome?** — 2025 case counts are down (38 vs 62 YTD through Oct), but transmission persists in Afghanistan/Pakistan reservoirs, surveillance is degraded by border closures/backlogs, funding is down 18%, and mass unvaccinated-child repatriation adds risk. Eradication target has slipped from June 2026 to a 2027 "interruption" goal (claude_news). 3. **Related market implications?** — No direct Polymarket equivalent found; unrelated markets (Fed rates, Iran, sports) returned as keyword noise. Other Kalshi long-shot/frontier markets (Musk-to-Mars 12%, new Pope candidates ~4-5%) show comparable low-probability tail pricing patterns but aren't substantively linked (kalshi_related, polymarket_related). 4. **Historical base rate?** — Zero years with zero WPV1 cases in ~37 years of GPEI tracking (1988–2024); best year on record (2021) still had 6 cases. Poisson modeling under status-quo case rates gives near-zero probability of a true zero year; even an aggressive halving-each-year optimistic scenario yields only ~17% cumulative probability by 2029 (code_execution). # Key facts (high-confidence, factual) 1. [claude_news/WHO] 2024 full-year WPV1 total: 99 cases, all in Afghanistan/Pakistan. 2. [claude_news] 2025 YTD (through Oct 22): 38 cases vs 62 in same 2024 period — a genuine decline. 3. [claude_news/WHO] Certification of eradication requires 3 consecutive zero-case years, but market only requires ONE reported zero-case year. 4. [code_execution] No calendar year since 1988 has recorded zero global WPV1 cases; 2021 lowest at 6 cases. 5. [claude_news] Original GPEI target to stop transmission by June 2026 has effectively slipped toward a 2027 goalpost. 6. [claude_news] Funding for AFG/PAK programs cut 18%; ~200,000 unvaccinated children among forced Afghan repatriates pose fresh transmission risk. # Cross-market signals - Kalshi related: No direct arbitrage market exists; other Kalshi "long-shot before-date" markets (Musk-Mars 12%, earthquake 30%, show-ending 54-60%) show varied tail pricing but no substantive link to polio. - Polymarket: No matching market found in search; results were noise (Fed rates, sports, geopolitics). - Sportsbook implied: N/A (not applicable to this event type). # Analyst opinions and speculation - GPEI/WHO officials (as of mid-2026) still characterize interruption of transmission as "achievable" but requiring adjusted strategy in southern Afghanistan — an optimistic-but-hedged official stance (GPEI TAG, claude_news). - Independent synthesis (code_execution) frames the scenario as requiring an aggressive, historically unprecedented monotonic case decline to reach zero in any single year before 2030, estimating overall probability in the "5–15%" range. - Health Policy Watch and CAGH-ACSM commentary emphasize fragility of recent gains (silent environmental spread, surveillance backlogs) rather than confidence in imminent eradication. # Directional lean per outcome - **Yes**: Supported by declining 2025 case trend (38 vs 62), GPEI stated goal to interrupt transmission by 2026-2027, and Kalshi price rising +4.8pp in the past week. Opposed by 37-year unbroken streak of nonzero years, persistent core reservoirs, funding cuts, surveillance backlogs, and migration-driven vaccination gaps. - **No**: Supported by robust historical base rate (0% precedent), Poisson modeling showing near-certain nonzero outcomes at current case rates, and multiple structural risk factors (funding, surveillance, conflict, migration) still active through 2026. This is the stronger-supported outcome overall. # Gaps / unknowns - No visibility into full 2025 or partial-2026 final case counts beyond Oct 2025 data point. - Unclear whether the "silent spread" detected via environmental surveillance will translate into confirmed clinical AFP cases in 2026-2029. - No Polymarket or sportsbook cross-check exists for direct comparison/arbitrage. - Uncertain how surveillance backlogs (unresolved samples) might delay case confirmation/reporting, potentially creating false "zero" reporting gaps rather than true epidemiological zero years. # Calibration anchors - Kalshi current YES price: **10.70%** (anchor), rising trend. - Historical precedent: 0 zero-case years in 37 years of tracking (1988–2024); closest year was 2021 with 6 cases. - Quantitative modeling range: ~5–17% probability of at least one zero-case year by 2029 under varying optimistic assumptions (code_execution).

1. Both forecasts anchor tightly to the 10.7% Kalshi price despite the brief noting the market is "thin" (avg 282 contracts/day) and has swung from 4.3% to 10.7% in just 41 days—neither forecaster flags this volatility as a reason for lower confidence in the anchor itself, nor explores whether the price is a lagging/noisy signal rather than a well-calibrated one. 2. Neither forecast explicitly addresses the "false zero" risk flagged in the Gaps section: surveillance backlogs from AFG-Pakistan border closures could delay case confirmation, producing an apparent zero-case year that is a reporting artifact rather than true epidemiological interruption—this could actually inflate Yes probability in ways the Poisson modeling doesn't capture. 3. Both forecasts lean heavily on the code_execution Poisson/optimistic-decline range (5–17%) but neither interrogates its assumptions (e.g., does it account for the current 38-vs-62 YoY decline rate, or just historical variance?); given 6 years remain (2024-2029) and only 2024-2025 are already "spent" as nonzero, four years (2026-2029) remain live candidates, which arguably deserves more weight than a static 5-17% cumulative range implies. 4. Neither forecaster discusses the asymmetry that WPV1 case counts are small integers (single/low double digits) concentrated in shrinking geographic reservoirs, meaning even modest additional progress (e.g., a 50% further YoY decline in 2026 or 2027) could plausibly produce a single-digit or zero year—closer scrutiny of the marginal trajectory (99→~46-50 projected 2025 full year) versus a flat "37-year streak" base rate might justify a somewhat higher Yes than both gave. 5. Both converge suspiciously close together (9% and 11%) around the anchor without meaningfully triangulating independent evidence—this convergence could reflect anchoring bias rather than independent verification, since the brief's own analyst synthesis range (5-15%) and quantitative modeling (5-17%) leaves room for more disagreement or a wider confidence interval than either forecaster expressed. 6. Neither forecast weighs the forced-repatriation shock (600,000 Afghan migrants, 200,000 unvaccinated children) as a potential one-off surge risk for 2026 specifically, which could make 2026 a near-certain "No" year and effectively compress the remaining window to 2027-2029—this temporal narrowing of viable "zero" candidate years isn't modeled explicitly by either.

10% (medium confidence)

Yes: 10% No: 90%

Both forecasters land near the 10.7% Kalshi anchor, and the critique's upward arguments (potential reporting-artifact 'zero' from surveillance backlogs; small integer case counts in shrinking reservoirs where one more 50% decline could reach zero) are roughly offset by its downward arguments (2024, 2025 and almost certainly 2026 are already spent as nonzero years, compressing the window to 2027–2029, with the repatriation shock and 18% funding cut making 2027 interruption unlikely to hold on schedule). GPEI targets have slipped repeatedly (June 2026 → 2027), and even if interruption occurred in 2027, the first fully clean calendar year would likely be 2028–2029 — leaving only a narrow path. The 37-year unbroken streak of nonzero years (best-ever 6 in 2021) plus Poisson-style modeling (5–17%) supports No strongly, while the thin, volatile market (4.3%–10.7% range in 41 days) argues against treating the anchor as precise rather than as a rough ceiling. I settle essentially at the anchor, 10% Yes.

Total pipeline time: 110.1s