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Question: will South Korea’s headline all‑items CPI print at ≥3.15% (displayed as 3.2%+) on one of the May (2026‑06‑01 UTC), June (2026‑07‑01 UTC) or July (2026‑08‑03 UTC) releases, otherwise no qualifying release by 2026‑08‑12? April CPI was already 2.6% y/y and index arithmetic shows only modest additional monthly rises (~+0.47–0.69% on the index) would produce a displayed 3.2%, so a near‑term crossing is plausible. Forecasters largely agree there is substantial upside risk from weak KRW, very high import prices, elevated PPI, and record‑high PMI input/output‑price signals, and the BOK has signalled greater inflation risk; however, a Reuters poll nowcast of ~3.0% for May, still‑soft core CPI (~2.2%), and active government measures (fuel‑tax cuts, price caps, frozen electricity tariffs) argue for meaningful dampening. A baseline time‑series model gives point estimates below threshold and places much mass in the no‑crossing tail, but analysts adjust that model upward because of pipeline/import shocks. The consensus implication is meaningful but not majority probability of a qualifying print by July, with the largest event probability concentrated on the May/June releases if pass‑through continues, and a substantial open‑tail probability that no qualifying release occurs by the cutoff.
Forecast: Probability distribution:
Key structural constraint: within the resolution window there are only three plausible qualifying CPI release timestamps (embargo typically 08:00 KST = 23:00 UTC prior day): 2026-06-01T23:00:00Z (May CPI), 2026-07-01T23:00:00Z (June CPI), and 2026-08-03T23:00:00Z (July CPI). If none meet the threshold by 2026-08-12T12:00:00Z, the outcome is in the open-after tail.
Substantive uncertainty is whether headline CPI reaches the effective trigger of 3.2% (if reported to one decimal) as early as May/June/July reference months. Analysts diverged mainly on the persistence of the energy/oil-driven impulse: one view extrapolates the recent rise (2.0%→2.6%) and cites bank commentary consistent with entry into the “3% range” soon; another emphasizes falling oil and consensus annual inflation forecasts around the mid‑2%s, implying a lower near-term chance of a 3.2% print.
Synthesis: I treat “within-window” as a modest majority outcome but far from certain, because (a) only three draws exist, (b) 3.2% is a discrete rounding cliff, and (c) plausible macro paths have CPI peaking later (August reference month, released in September, outside the window). I center on ~55% probability of hitting ≥3.15% (≥3.2% if 1-decimal) by the Aug 4 release, with remaining ~45% in the open-after bin. Conditional mass is concentrated on the scheduled release moments, with the Aug 4 (Jul CPI) release the single most likely first crossing if it happens in-window.
An amateur forecast commonly (i) spreads probability continuously across calendar days rather than concentrating it on the discrete official CPI release timestamps, (ii) ignores the KST embargo time (which shifts the resolving UTC date to the prior day at 23:00Z), (iii) fails to represent the substantial “not by Aug 12” risk using past-upper-bound percentile dates, and (iv) overlooks the rounding cliff (3.15% effectively requiring a reported 3.2% if only one decimal is published). This forecast explicitly encodes the three feasible in-window release moments and a calibrated open-after tail, so it should be better calibrated than a naive extrapolation. Confidence in improvement: moderate (macro drivers remain genuinely uncertain).
Forecast rationale (numeric):
— Iteration 1 — Across the rationales, the forecast is driven by a few shared considerations:
The shared reasoning is that rising inflation momentum, elevated upstream costs, and oil-related pressures make a crossing plausible in the June–July 2026 release window, but there is still meaningful uncertainty about whether those pressures persist long enough to produce the first ≥3.15% print before late summer.
— Iteration 2 — The forecasts converge on a summer 2026 upward move in South Korea CPI, driven primarily by a mix of energy-price pass-through, base effects, and fiscal stimulus, but tempered by policy offsets that could delay the crossing.
The collective view is that South Korea’s CPI is biased upward in the near term, with the first ≥3.15% YoY reading most likely in summer 2026, but there is meaningful uncertainty because government interventions and oil-price volatility could postpone the crossing.
— Iteration 3 — The forecasts share a common framework: they start from the current South Korean CPI YoY reading of about 2.6% and judge whether it can rise to 3.15% on one of the monthly release dates. Because CPI is reported monthly, the outcome is treated as a discrete event tied to specific release dates rather than a continuous date range.
The collective reasoning is that South Korea’s CPI is close enough to 3.15% that a summer 2026 crossing is plausible, but not assured. The balance of evidence hinges on whether rising energy costs and recent inflation momentum can overcome still-moderate core inflation and easing oil prices. The most common near-term expectation is a discrete monthly release in summer 2026, but there is meaningful uncertainty, and some models place substantial weight on a much later breach.
Resolution Mechanics and Release Schedule South Korea reports its Consumer Price Index (CPI) to one decimal place, meaning the 3.15% threshold necessitates an officially reported print of 3.2%. The active resolution window captures exactly three strictly scheduled releases by Statistics Korea: the May, June, and July data, which are published in early June, July, and August, respectively.
Macroeconomic Pressures and Base Effects Bridging the gap from the April baseline of 2.6% to the 3.2% target requires a steep jump. Forecasters identify a strong confluence of upward macroeconomic pressures, primarily driven by high global energy prices, a depreciating Korean Won, surging import/producer prices, and seasonal agricultural and livestock shocks. Furthermore, the mathematical “base effects” from unusually low month-over-month inflation in May and June of 2025 will mechanically push the year-over-year figures higher throughout the early summer.
Government Interventions and the Expiration Cliff Despite intense inflationary drivers, the South Korean government has implemented aggressive administrative price controls that act as a strict bottleneck. Extended fuel tax cuts and frozen public utility tariffs are actively artificially suppressing consumer costs. Forecasters widely agree that these measures will likely blunt the impact of global shocks in the May and June CPI reports.
Synthesis and Timing Because these state-mandated caps on utility and fuel costs are slated to expire at the end of July, the most severe inflationary shock is delayed. While a breach of the threshold is distinctly possible in the July data (released in early August) if state utilities immediately hike tariffs, the consensus points to a delayed peak. With fuel subsidies ending in late summer, forecasters anticipate the true inflation peak will materialize in the August data. Because the August report is published in September, there is broad agreement that the most likely threshold breach falls entirely outside the question’s maximum resolution window.
Question: On what date will South Korea’s consumer price index first be reported at 3.15% year-over-year or higher? Final Prediction: Probability distribution:
Total Cost: extra_metadata_in_explanation is disabled Time Spent: extra_metadata_in_explanation is disabled LLMs: extra_metadata_in_explanation is disabled Bot Name: extra_metadata_in_explanation is disabled
Forecaster 1: Probability distribution:
Forecaster 2: Probability distribution:
Forecaster 3: Probability distribution:
The research summarizes South Korea’s inflation situation as of May 29, 2026: April 2026 CPI was 2.6% year‑over‑year (the highest in 21 months), with petroleum prices up 21.9% in April contributing about 0.84 percentage points to overall inflation. Government measures (maximum oil price system and fuel tax cuts) are estimated to have reduced inflation by roughly 1.2 percentage points—meaning April’s CPI would have been about 3.8% without those interventions. The Bank of Korea (BOK) raised its 2026 inflation forecast to 2.7% and warned headline CPI could exceed 3% in the second half of 2026; Trading Economics projects inflation reaching 3.2% by the end of Q2 (June 2026). Core inflation remains more moderate (around 2.2–2.4%), and recent drivers besides oil include service cost increases tied to fuel and some exchange‑rate pressure from won depreciation.
The research identifies the CPI release cadence (monthly data typically published in the first week of the following month, e.g., May data released ~June 5–6) and highlights the most relevant near‑term releases for the question (May, June, and July 2026 CPIs). It outlines factors favoring a 3.15%+ print (BOK warnings, sustained high oil prices and base effects, Trading Economics’ Q2 forecast, and the April “would‑have‑been” calculation) and factors against it (government price interventions, moderate core inflation, and conservative forecasts such as J.P. Morgan’s). Key uncertainties are the trajectory of the Middle East conflict and oil prices, the duration of government interventions, exchange‑rate movements, and potential monetary policy responses; quantitatively, April’s 2.6% reading implies a rise of about 0.55 percentage points would be needed to reach 3.15%.
Websites / sources used (as cited in the research):
Most Recent Data:
Oil Price Shock (Primary Driver):
Government Interventions:
Secondary Factors:
Bank of Korea (BOK) - May 28, 2026:
Trading Economics Forecast:
J.P. Morgan Global Research:
Timing Pattern:
Potential Qualifying Releases within Question Window (May 29 - August 12, 2026):
Historical Context for 3%+ Inflation in South Korea:
Recent 3%+ Episodes:
Oil Shock Precedents:
Impact Metrics:
No specific prediction markets found for this exact question. My searches did not identify any Polymarket, Metaculus, or other prediction market questions specifically forecasting when South Korea’s CPI will reach 3.15%+.
Factors Favoring 3.15%+ Being Reached:
Factors Against 3.15%+ Being Reached:
Critical Uncertainties:
Probability-Relevant Data Points:
Most Likely Scenarios:
Base Rate Insight: South Korea has not experienced 3%+ YoY inflation since approximately mid-2024, representing roughly 2 years. The current shock is significant but less severe than the 2022 Russia-Ukraine shock, and government interventions are actively containing price pressures.
Conditioning on the question not being annulled.
(a) Time left until known. The official 2026 CPI schedule puts the next three relevant all-items CPI releases at 2026-06-02 08:00 KST, 2026-07-02 08:00 KST, and 2026-08-04 08:00 KST, i.e. 2026-06-01T23:00:00Z, 2026-07-01T23:00:00Z, and 2026-08-03T23:00:00Z. So the first possible resolution is about 3–4 days from 2026-05-29, and if none qualify the formal latest determination is by 2026-08-12T12:00:00Z. The official CPI press release format uses an 08:00 KST embargo time, which is the resolving time here. (mods.go.kr)
(b) Outside view. There are only three scheduled monthly release opportunities before the range maximum. Historically, South Korea was in a high-inflation regime in 2022–2023, with annual CPI inflation of 5.1% and 3.6%, but it slowed to 2.3% in 2024 and 2.1% in 2025. In early 2026, headline CPI was 2.0% in January, 2.0% in February, 2.2% in March, and 2.6% in April, so the base rate is not simply “already at 3%+”; a further step-up is needed. (kostat.go.kr)
(c) Inside view. April’s all-items CPI was 119.37, up 0.5% m/m and 2.6% y/y; to hit 3.15% y/y for May, the May index needs to be about 119.93, requiring roughly another 0.47% m/m from April. That is plausible in an oil shock, but it is a high monthly print and the Reuters poll for May CPI was 3.0%, below the effective one-decimal qualifying threshold of 3.2%. (mods.go.kr)
(d) Outcome if nothing changed. If the April CPI index level were simply carried forward, May/June/July y/y rates would remain below the 3.15% threshold, so the outcome would be >2026-08-12T12:00:00Z.
(e) Outcome if the current trend continued. If the Jan–Apr 2026 monthly CPI trend continued, I would expect May to be close but more likely just under the threshold, and June to qualify; that points to the June 2026 CPI release at 2026-07-01T23:00:00Z.
(f) Experts and markets. The Bank of Korea revised its 2026 CPI forecast up to 2.7% because of the oil shock and demand pressures, ING expected inflation to rise further and reach “around 3% as early as June,” while Trading Economics showed a May consensus/forecast near 3.0%/2.9% but an end-of-quarter forecast of 3.2%. I found no liquid prediction market for this exact resolution, so I weight economist forecasts more than market pricing. (bok.or.kr)
(g) Unexpected low / earlier scenario. May CPI prints at 3.2% because fuel/airfare pass-through and a food-price base effect are stronger than surveyed economists expected, or because the fuel price cap becomes less binding. That resolves at 2026-06-01T23:00:00Z.
(h) Unexpected high / later scenario. A U.S.–Iran de-escalation drives oil materially lower, while Korea maintains fuel caps, food vouchers, and utility-price freezes; in that case headline CPI stays around 2.8–3.1 through July and the question resolves as >2026-08-12T12:00:00Z. Recent oil reporting already showed prices easing on peace-deal hopes, though still above pre-war levels. (axios.com)
Rationale. I start from the base rate that South Korea has only three discrete chances before the cutoff and had been running near 2% before the oil shock. The inside-view evidence raises the probability substantially: April was already 2.6%, petroleum prices were a large positive contribution, and several forecasters see inflation around or above 3% by June. But the May Reuters consensus at 3.0%, government price suppression, and core inflation near 2.2% keep me from putting most mass on the earliest release. My rough event-date mass is: 27% on the May CPI release, 38% on the June CPI release, 18% on the July CPI release, and 17% no qualifying release by the range maximum. Dates beyond the cutoff in the right tail below represent my uncensored belief about when 3.15%+ would first be reported if the question were not capped; formally, any such case resolves as >2026-08-12T12:00:00Z.
Percentile 0.1: 2026-06-01T23:00:01Z (oldest date) Percentile 1: 2026-06-01T23:00:02Z Percentile 5: 2026-06-01T23:00:03Z Percentile 10: 2026-06-01T23:00:04Z Percentile 20: 2026-06-01T23:00:05Z Percentile 30: 2026-07-01T23:00:01Z Percentile 40: 2026-07-01T23:00:02Z Percentile 50: 2026-07-01T23:00:03Z Percentile 60: 2026-07-01T23:00:04Z Percentile 70: 2026-08-03T23:00:01Z Percentile 80: 2026-08-03T23:00:02Z Percentile 90: 2026-09-01T23:00:01Z Percentile 95: 2026-11-02T23:00:01Z Percentile 99: 2027-06-01T23:00:01Z Percentile 99.9: 2029-01-02T23:00:01Z (newest date)
Conditioning on the question not being annulled.
(a) Time left until the outcome is known.
The first possible resolving release is the May 2026 CPI report scheduled for 2026-06-02 08:00 KST, i.e. 2026-06-01T23:00:00Z. If no qualifying CPI is reported by the July 2026 CPI release, the question will be known by the cutoff 2026-08-12T12:00:00Z, about 75.5 days after 2026-05-29T00:00:00Z. The official monthly schedule shows May CPI on June 2, June CPI on July 2, and July CPI on August 4, all at 08:00 KST in the monthly plans. (kostat.go.kr)
(b) Outside view.
South Korea has recently been a roughly 2% inflation economy: annual CPI inflation was 3.6% in 2023, 2.3% in 2024, and 2.1% in 2025, and the official April release table shows monthly year-over-year CPI running from 2.0% to 2.6% in January-April 2026. So the base rate from the last ~1.5 years is that a 3.2%-reported headline CPI print is not common in any given 3-month window. (kostat.go.kr)
(c) Inside view.
The April 2026 CPI release is already close to the threshold: all-items CPI was 119.37, up 0.5% m/m and 2.6% y/y, with transport up 9.7% y/y and 3.4% m/m. Because May 2025 CPI was only 116.27, a May 2026 all-items index around 119.93 would round/report as at least 3.2% y/y, requiring roughly another 0.47% m/m from April—basically a repeat of April’s monthly increase. (kostat.go.kr)
(d) Outcome if nothing changed.
If the April price level simply stayed flat, the May/June/July year-over-year rates would remain below 3.15%; that would imply no qualifying release before 2026-08-12T12:00:00Z.
(e) Outcome if the current trend continued.
If April’s 0.5% monthly increase or the recent accelerating oil-pass-through trend continued, the May CPI release on 2026-06-01T23:00:00Z would likely qualify. If the monthly pace slows to something closer to 0.25%-0.35%, the June CPI release on 2026-07-01T23:00:00Z becomes the more likely first qualifying date.
(f) Expectations of experts and markets.
The Bank of Korea raised its 2026 CPI inflation forecast to 2.7% and explicitly attributed the revision to direct and indirect oil-shock effects plus stronger demand, while noting high uncertainty around the Middle East war. Trading Economics shows a May-release consensus around 3.0% and its own forecast around 2.9%, but also says inflation is expected to reach 3.2% by the end of Q2, which points to the June data release as a central candidate. I found no liquid direct prediction market for this exact resolution. (bok.or.kr)
(g) Unexpected low/earlier scenario.
The earlier outcome is constrained by the schedule, so the main “low” scenario is 2026-06-01T23:00:00Z: May CPI qualifies because fuel prices, airfares, and oil-linked services rise again, the won weakens, or the government cannot fully offset the oil shock.
(h) Unexpected high/later scenario.
A high outcome happens if the ceasefire/de-escalation news pulls oil down, the fuel price cap and tax cuts continue suppressing domestic fuel CPI, fresh food remains deflationary, and core stays around 2.2%; recent AP reporting noted optimism about extending a ceasefire and oil prices slipping, though still above pre-war levels. In that case, no release before 2026-08-12T12:00:00Z qualifies. (apnews.com)
Rationale.
I start from the outside view that South Korea has not recently been printing 3%+ headline CPI, and the core measures are still moderate. But I update strongly upward from that base rate because April already reached 2.6% y/y with a 0.5% monthly increase, the May base month is weak, and official/expert forecasts now embed an oil-shock inflation path. My probability mass is roughly: 32% on the May CPI release, 38% on the June CPI release, 15% on the July CPI release, and 15% after the cutoff. That makes the median the June CPI release, but leaves a real right tail for price controls, oil de-escalation, and food/core disinflation.
Percentile 0.1: 2026-06-01T23:00:01Z Percentile 1: 2026-06-01T23:00:01Z Percentile 5: 2026-06-01T23:00:01Z Percentile 10: 2026-06-01T23:00:01Z Percentile 20: 2026-06-01T23:00:01Z Percentile 30: 2026-06-01T23:00:01Z Percentile 40: 2026-07-01T23:00:01Z Percentile 50: 2026-07-01T23:00:01Z Percentile 60: 2026-07-01T23:00:01Z Percentile 70: 2026-07-01T23:00:01Z Percentile 80: 2026-08-03T23:00:01Z Percentile 90: 2026-09-01T23:00:01Z Percentile 95: 2026-11-02T23:00:01Z Percentile 99: 2027-07-01T23:00:01Z Percentile 99.9: 2028-08-01T23:00:01Z
Conditioning on the question not being annulled.
The critic’s main point is valid: this is not just a “will Korea print above 3%?” question. Because the official headline rate is likely reported to one decimal, the effective threshold is a reported 3.2%, and 3.0–3.1% does not resolve. That makes my earlier 87% by the July CPI release too aggressive.
I still think the median should remain the June CPI release, published July 2 KST. The official CPI path is already close: April CPI was 119.37, up 2.6% YoY and 0.5% MoM, and the May/June/July 2025 base indices imply only about +0.47% by May, +0.51% cumulative by June, and +0.69% cumulative by July from April 2026 to reach the threshold. The official schedule has the relevant releases on June 2, July 2, and August 4 KST. (kostat.go.kr)
But I am reducing the early probability. A new-to-this-round point that matters is the strength of policy suppression: more than 96% of gas stations reportedly kept gasoline prices unchanged under the fuel-price-cap regime, with government caps frozen again in early May. That makes a May CPI jump to a reported 3.2% less likely than my original 25%. (en.yna.co.kr)
I still do not want to overcorrect bearishly. The Bank of Korea has just raised its 2026 CPI forecast to 2.7%, says inflation is expected to increase further as oil-price spillovers broaden, and explicitly flags oil, FX, pass-through, and government price-stabilization measures as the key uncertainties. The won around 1,500 per dollar and continued pass-through keep June/July meaningfully live. (bok.or.kr)
The oil backdrop is also two-sided rather than simply bearish: recent headlines point to possible de-escalation, but oil prices remain above pre-war levels and Hormuz disruptions have not fully normalized, while the IEA described severe 2Q26 oil-market disruptions and Korean import effects. (apnews.com)
My updated probability split:
So I accept the critic’s fatter right tail, while keeping the same median.
Updated prediction:
Percentile 0.1: 2026-06-02
Percentile 1: 2026-06-02
Percentile 5: 2026-06-02
Percentile 10: 2026-06-02
Percentile 20: 2026-07-02
Percentile 30: 2026-07-02
Percentile 40: 2026-07-02
Percentile 50: 2026-07-02
Percentile 60: 2026-08-04
Percentile 70: 2026-08-04
Percentile 80: 2026-09-02
Percentile 90: 2026-10-02
Percentile 95: 2026-12-02
Percentile 99: 2027-07-02
Percentile 99.9: 2029-01-03
Modal: Aug 12, 2026 to Oct 26, 2026 (55.0%) • partial_shift • 7m9s
Reading: strict
The resolution criteria are highly specific and literal: an exact numeric threshold (3.15%, with an explicit rounding rule for one-decimal-place reports), a precise UTC timestamp window, named source (Ministry of Data and Statistics), and defined tie-breaking rules for discrepancies — leaving little room for charitable or expansive interpretation.
Total evidence registered (shared pool): ?
| Variant | Perspective | Model | Turns | Tools | Status |
|---|---|---|---|---|---|
| 0 | inside_view (inside_view_v1) | anthropic/claude-sonnet-4-6 | 25 | 37 | OK |
| 1 | outside_view (outside_view_v1) | anthropic/claude-sonnet-4-6 | 25 | 42 | OK |
| 2 | contrarian (contrarian_v1) | anthropic/claude-sonnet-4-6 | 25 | 46 | OK |
Evidence confidence: medium
high evidence]Institutional forecasts (BoK 2.7%, KDI 2.7%, ING 2.2%, FocusEconomics 2.2%) all peak well below 3.15%. Government price-suppression measures (fuel cap, utility freeze, food vouchers) are actively limiting pass-through. Core inflation remains anchored near 1.8–2.4%. Oil price shock may moderate if Middle East tensions ease. The 0.55pp gap from the April reading is substantial to close in one or two months.
CPI has been accelerating sharply (+0.4pp in one month). PPI surged a 28-year record in April. Import prices at 28-year high. Won at 17-year REER low. Government officials themselves acknowledged possibility of ‘low 3%’ readings. Base effects are favorable in May–August 2026 vs 2025.
low evidence]South Korean officials and BoK acknowledged May 2026 CPI could reach ‘low 3% range.’ April PPI surged 2.5% MoM (28-year high), with 1–3 month lag to CPI. Import price index at 28-year high with pass-through timing pointing to May. Favorable base effect from May 2025’s 1.9% reading. Won weakness (8.92% 12-month decline) amplifying import costs. ING expected inflation ‘towards 3% as early as June 2026.’
Going from 2.6% to ≥3.15% in one month would be a +0.55pp jump — large by recent South Korean standards. Government countermeasures (fuel cap, food vouchers) are most actively deployed precisely for the May reporting period. Institutional forecasts do not anticipate this pace. BoK’s own forecast peaks at 2.7% annual average.
low evidence]If May 2026 CPI rises to 2.8–3.1% range (plausible per official signals), additional pass-through from import/energy prices could push June further. June 2025 base was 2.2% (moderate, not high), providing some upward base effect. Cumulative KRW weakness and import pass-through reaching consumers by June 2026 (2–3 month lag from the March import price peak). ING forecast expected 3% ‘as early as June 2026.’
Government measures likely still in effect. BoK forecasting only 2.7% for full year — a June reading above 3.15% would require the year average to run well above forecast, implying the BoK is significantly underestimating. Oil prices could moderate. A high May reading might prompt additional government interventions.
low evidence]July 2025 base was 2.1% (low), providing upward base effect. Cumulative inflation pressures from energy, import costs, and KRW weakness may fully pass through by July 2026. Some government measures (e.g. fuel cap) are temporary and may expire. The August 2025 SKT telecom base effect (1.7%) would actually apply to August 2026 data (released September, outside window), but July 2025’s 2.1% base still gives a moderate boost.
The last release in the window (August 4) assumes a three-month sustained acceleration to ≥3.15% from 2.6% — a 0.55pp or more increase over a quarter in which institutional forecasts see only 2.7% average. Government measures extend over multiple months. BoK would likely intervene (rate hikes) if inflation approached 3%.
inside_view_v1)Inside View Causal Analysis
Current state → mechanism → outcome chain:
Starting point: South Korea CPI at 2.6% YoY in April 2026 (per source 1, 3, 4). The threshold is 3.15%, requiring a +0.55pp gap closure within 3 monthly releases (June 2–3, July 2, August 4, 2026).
Causal mechanism for threshold breach:
- PPI surged +2.5% MoM in April 2026 (28-year record, source 26), with 1–3 month CPI lag → pushes toward 3% in May/June
- Import prices +16.1% MoM in March 2026 (28-year high, source 44), pass-through expected ~May–June 2026 (source 45)
- KRW at 17-year REER low (85.06, source 47), won down 8.92% over 12 months (source 42) → amplifying import cost pass-through
- Petroleum +21.9% YoY in April (source 27, 37) → energy prices still elevated
- Favorable base effects: May 2025 = 1.9% (source 19), June 2025 = 2.2%, July 2025 = 2.1% (source 31)
- Officials acknowledged May CPI could reach “low 3% range” (source 21); ING: “towards 3% as early as June 2026” (source 20)
Causal mechanism against threshold breach:
- BoK official forecast: 2.7% annual average (source 14, 24, 32) — well below 3.15%
- KDI: ~2.7% for 2026 (source 8, 10); ING annual avg: 2.2% (source 46); FocusEconomics: stable core ~2.2% (source 40)
- Active government price suppression: fuel cap extended (source 38), food vouchers, frozen utility tariffs (source 12, 48)
- Core inflation anchored at ~1.8–2.4% (source 48)
- BoK expected to hike rates if inflation approaches 3% (source 39)
Scenario weighting by evidence strength:
The “no qualifying release” scenario is tagged
relative_evidence_strength: high— meaning it should carry materially more mass than the three “qualifying release” scenarios which are all taggedlow. This is the dominant causal signal.The key insight is that going from 2.6% to 3.15%+ requires +0.55pp in a context where:
- ALL institutional forecasters cap at 2.7% annual average
- Government has active suppression measures precisely targeting energy and food
- The “officials acknowledged low 3% range” language means ~3.0–3.1%, NOT 3.15+%
- Even ING’s bullish scenario says “towards 3%”, not “towards 3.15%”
- The rounding rule means only a report showing 3.2% (or finer ≥3.15%) resolves
Probability allocation:
Given the high-evidence “no qualifying release” scenario, I assign ~70% to bins 8+ (resolves after Aug 12).
For the three qualifying scenarios (all low-evidence):
June 2–3 release (bin 1: Jun 7–16 covers this date): The May 2026 CPI would need to jump from 2.6% to ≥3.15% in one month. Officials said “low 3% range” (i.e., 3.0–3.1%), which is BELOW the threshold. PPI lag and import pass-through are compelling but government measures are maximal now. ~6% probability of hitting ≥3.15%.
- June 2, 2026 (KST 08:00 = May 31, 2026 23:00 UTC) falls in May 29 – Jun 7 (bin_0). Actually wait: June 2 KST at 08:00 = June 1 UTC at 23:00. So this falls in May 29 to Jun 7 (bin_0).
July 2 release (bin_2: Jun 16–26 covers this? No: July 2 falls in bin_3 Jun 26–Jul 5). June 2026 CPI data, released July 2. If May data came in near 3%, June could push higher. ~8% probability.
August 4 release (bin_4: Jul 5–15? No. August 4 falls in bin_6: Jul 24–Aug 3 or bin_7: Aug 3–12). August 4 is in Aug 3–Aug 12 (bin_7). July 2026 CPI data. Another month of pass-through but BoK may have hiked. ~7% probability.
Wait, let me map the release dates to bins more carefully:
- June 2, 2026 at 08:00 KST = June 1, 2026 at 23:00 UTC → falls in May 29 – Jun 7 (bin_0) ✓
- July 2, 2026 at 08:00 KST = July 1, 2026 at 23:00 UTC → falls in Jun 26 – Jul 5 (bin_3) ✓
- August 4, 2026 at 08:00 KST = August 3, 2026 at 23:00 UTC → falls in Aug 3 – Aug 12 (bin_7) ✓
So the bins containing possible qualifying releases are: bin_0, bin_3, bin_7, and bin_8+ (never happens in window).
Cumulative logic: P(≥3.15% by release 1) ≈ 6%, P(≥3.15% by release 2 | not release 1) ≈ 9%, P(≥3.15% by release 3 | not by release 2) ≈ 8%.
P(event at release 1) ≈ 0.06 → bin_0 P(event at release 2) ≈ 0.94 × 0.09 ≈ 0.085 → bin_3 P(event at release 3) ≈ 0.855 × 0.08 ≈ 0.068 → bin_7 P(no event in window) ≈ 0.855 × 0.92 ≈ 0.787 → but need to also subtract release 3 chance…
Let me redo:
- P(bin_0) = 0.06
- P(bin_3) = (1-0.06) × 0.09 ≈ 0.085
- P(bin_7) = (1-0.06-0.085) × 0.08 ≈ 0.855 × 0.08 ≈ 0.068
- P(bin_8+) = 1 - 0.06 - 0.085 - 0.068 ≈ 0.787
The bins 1, 2, 4, 5, 6, 9, 10, 11, 12 should get near-zero probability (no releases scheduled there, and “after the window” is captured in bin_8).
Spreading the bin_8+ mass across bins 8-12 with most in the immediately-after period and longer-term tail (bin_8):
- bin_8 ≈ 0.55 (events that happen soon after Aug 12, somewhat likely given trajectory)
- bin_9 ≈ 0.10
- bin_10 ≈ 0.07
- bin_11 ≈ 0.05
- bin_12 ≈ 0.04
Wait — the question says “If no qualifying release occurs on or before 2026-08-12, the question resolves as >2026-08-12T12:00:00+00:00.” So bin_8+ IS the “never” outcome. But bins 8-12 represent WHEN in the future it happens (or specifically what the TE forecast says about timing beyond the window). Given the question resolution rules, everything in bins 8+ actually just means “not within window” since all those bins represent dates when NO release will be published during the question window.
Actually re-reading: bins 8-12 correspond to LATER date ranges for the CPI release. But if the question resolves as “>2026-08-12T12:00:00Z”, it takes the sentinel value. In this prediction market framing, if the event doesn’t happen in the window, the resolution date is treated as a late date. Looking at the bins:
- bin_8: Aug 12, 2026 to Oct 26, 2026
- bin_9: Oct 26, 2026 to Jan 10, 2027
- bin_10: Jan 10, 2027 to Mar 26, 2027
- bin_11: Mar 26, 2027 to Jun 10, 2027
- bin_12: After Jun 10, 2027
These seem to represent WHEN the threshold would eventually be hit if not in the window. Given institutional forecasts suggest ~2.7% for 2026, the threshold might be hit in late 2026 or 2027 if energy price pressures persist. But the question resolves as the sentinel value if not in window. I’ll treat bins 8-12 as the “event doesn’t happen in window” + “when it would eventually happen” distribution.
Given the 70%+ probability of no qualifying release in the window, I’ll concentrate this mass in bin_8 through bin_12, with judgment calls on when it would eventually happen.
Final allocation:
- bin_0: 0.06 (June 2 release, May 2026 data)
- bin_1: 0.01 (no scheduled release)
- bin_2: 0.01 (no scheduled release)
- bin_3: 0.08 (July 2 release, June 2026 data)
- bin_4: 0.01 (no scheduled release)
- bin_5: 0.01 (no scheduled release)
- bin_6: 0.01 (no scheduled release)
- bin_7: 0.06 (Aug 4 release, July 2026 data)
- bin_8: 0.40 (resolves as >Aug 12, likely hits threshold Q3-Q4 2026)
- bin_9: 0.15 (Q4 2026)
- bin_10: 0.08 (Q1 2027)
- bin_11: 0.07 (Q2 2027)
- bin_12: 0.05 (later)
Sum: 0.06+0.01+0.01+0.08+0.01+0.01+0.01+0.06+0.40+0.15+0.08+0.07+0.05 = 1.00 ✓
outside_view_v1)Reference class: recent months for South Korea when headline (all-items) CPI has been ≥3.15% in a rolling 1–3 month window. Base rate: essentially zero in the recent ~12–18 months — CPI has remained below 3% since mid‑2024 and April 2026 was 2.6% (the most recent high) (sources 1, 3, 16, 33). Adjustment: +/− adjustments are small-to-moderate because of two opposing, well-documented forces. Upside evidence (PPI +2.5% MoM in April, import prices and REER weakness, favorable May–July 2025 bases, officials warning May could reach low‑3% range) increases short‑term chance (sources 26, 44, 45, 47, 19, 21). Downside evidence (Bank of Korea, KDI, FocusEconomics, ING institutional forecasts clustering around 2.2–2.7% and active government fuel/utility caps) makes a rapid jump to ≥3.15% within three scheduled releases unlikely (sources 8, 14, 24, 40, 46, 12, 38). Because the brief flags the “no event within window” scenario as the strongest evidence (relative_evidence_strength: high) I place materially more mass on no qualifying release by the window cutoff (which resolves as >2026‑08‑12T12:00:00Z and maps to the first bin after the window in the provided binning scheme: bin_8). Final (outside‑view) allocation: 80% that no qualifying CPI ≥3.15% release occurs on-or-before 2026‑08‑12 12:00Z (bin_8), and the remaining 20% distributed across the three scheduled release dates in the window weighted by plausibility: 8% on the June 2–3 release (May data → bin_0) given official signals that May could print low‑3% and rapid pass‑through is possible but hard (sources 15, 21, 26); 6% on the July 2 release (June data → bin_3) reflecting a 1–2 month pass‑through scenario if May is elevated (sources 20, 45); 6% on the August 4 release (July data → bin_7) as the tail of a sustained pass‑through and base‑effect buildup (sources 11, 22). I weight the high‑evidence “no event” scenario heavily per the brief’s scenario tagging and the clustering of institutional forecasts; the small probabilities on the three release dates reflect the credible but lower‑strength upside evidence. This forecast follows the interpretation’s strict reading of the resolution rules (use the first official scheduled release value and the stated rounding rule for one‑decimal releases) and respects the brief’s medium confidence in evidence by leaving notable residual uncertainty around the early release dates (sources 11, resolution criteria).
contrarian_v2)Adversarial reading
The bulk of the evidence (BoK/KDI/ING/FocusEconomics forecasts all capping at 2.7% annual average, active government price-suppression measures still in force, core inflation anchored at 1.8–2.4%) pulls strongly toward no qualifying CPI release reaching 3.15% within the three-release window ending 12 Aug 2026.
Counter-evidence found (or absence)
The only counter-evidence consists of the low-strength scenarios (PPI/import-price surge, officials acknowledging possible “low 3%” May reading, favorable 2025 base effects) that could produce a June or July breach; these are explicitly tagged low relative_evidence_strength and rest on single-source signals that conflict with the institutional forecasts.
Distribution implications
Because counter-evidence is thin, the distribution places materially higher mass on the post-window bins (especially bin_8) than a naïve uniform reading would suggest. The high-evidence “no event” scenario receives ~0.80 total probability, expressed primarily in bin_8 with small spill-over into adjacent late bins; early bins receive only residual probability consistent with the low-strength upside scenarios.
Strategy: logit_mean • Drafts: 3/3
anchoring_v1The draft rationale places ~72% mass in Aug 12–Oct 26, 2026 (bin_8), treating it as the “no qualifying release” sentinel. However, this conflates the strict “resolves as >2026-08-12” outcome with a specific later-event timing window. More importantly for anchoring: the draft’s modal scenario (no event in window) is sound, but within the window, the forecaster uses the ING quote “towards 3% as early as June 2026” and official signals of a “low 3% range” for May as if they support the threshold being reached. “Towards 3%” means approaching 3.0%, not ≥3.15%. The forecaster acknowledges this (“officials said ‘low 3% range’ (i.e., 3.0–3.1%), which is BELOW the threshold”) but then still assigns 6-8% to bin_0 and bin_3 — these bins are anchored slightly optimistically relative to what the cited language actually implies. The “low 3% range” language (source 21) and “towards 3%” (source 20) specifically cap expected values BELOW the resolution threshold; a flat-prior reading of “low 3%” centers expected outcomes around 3.0–3.1%, not 3.15–3.2%. The probability on in-window resolution bins should be lower, with more mass shifted to bin_8.
ceiling_v1Top concern: the draft violates a hard structural constraint in the brief — only three official monthly CPI releases fall inside the resolution window (May data released June 2, June data released July 2, July data released Aug 4; source 11,15). Using the brief’s embargo-time rule (08:00 KST = 23:00 UTC prior day) those three releases map to exactly three bin_ids (June 2 → bin_0; July 2 → bin_3; Aug 4 → bin_7). Any nonzero mass assigned to other in-window bins (bin_1, bin_2, bin_4–bin_6) is structurally impossible and must be redistributed. I reweight the forecast so only bin_0, bin_3, in-window (bin_7) and bins after the window (bin_8–bin_12) carry probability.
math_v1The draft’s probability distribution exhibits significant internal inconsistencies. The rationale describes three low-evidence scenarios assigned 6%, 8%, and 8% probability respectively (totaling ~22% for a qualifying release), yet the submitted distribution assigns only 15.2% total to the three bins containing scheduled CPI releases (bin_0: 6.96%, bin_3: 5.16%, bin_7: 6.31%), a 30% shortfall. Simultaneously, the draft assigns 72.4% to bins 8+ (“no qualifying release”), contradicting the rationale’s stated intention to weight the high-evidence “no event” scenario “heavily per the brief’s scenario tagging” — if 80% (as stated in the outside-view section) were intended, the allocation should reflect this. The discrepancy arises from treating bins 8-12 as representing both (1) the “never happens” outcome and (2) a distribution over when the event would eventually occur, conflating two distinct semantic cases that shouldn’t both draw probability mass.
Reviews consumed: 3
The ceiling reviewer correctly flagged a structural constraint: only three scheduled CPI releases fall in the window (June 2 → bin_0, July 2 → bin_3, Aug 4 → bin_7); other in-window bins (1, 2, 4, 5, 6) are structurally impossible and must be zeroed. I accepted this fully — it is a deterministic mapping from the published schedule. The math reviewer flagged internal inconsistency between the rationale’s intended ~22% in-window mass and the draft’s actual 18% allocation, plus residual probability in impossible bins; I integrated both points by zeroing impossible bins and consolidating in-window mass into the three valid release bins. The anchoring reviewer argued for shifting mass away from in-window bins because ‘low 3%’ (sources 20, 21) means 3.0–3.1%, below the 3.15% threshold; I partially accepted this by keeping in-window total moderate (~20%) rather than higher, but didn’t cut it further because PPI/import-price shocks and base effects give a genuine tail above what the central-tendency language implies. For after-window mass, I followed the draft’s logic that the threshold is more likely to be eventually breached in the months immediately after Aug 12 (when the same pass-through pressures continue) rather than years later, putting the bulk in bin_8 with a declining tail.
[anchoring] Reduce in-window probability further because ‘low 3%’ language caps at 3.0–3.1%, below the 3.15% threshold.
[math] Outside-view variant said 80% no-event, draft only allocated 72%; resolve to higher post-window mass.
| Bin | Probability |
|---|---|
| May 29, 2026 to Jun 07, 2026 (bin_0) | 6.0% |
| Jun 07, 2026 to Jun 16, 2026 (bin_1) | 0.0% |
| Jun 16, 2026 to Jun 26, 2026 (bin_2) | 0.0% |
| Jun 26, 2026 to Jul 05, 2026 (bin_3) | 8.0% |
| Jul 05, 2026 to Jul 15, 2026 (bin_4) | 0.0% |
| Jul 15, 2026 to Jul 24, 2026 (bin_5) | 0.0% |
| Jul 24, 2026 to Aug 03, 2026 (bin_6) | 0.0% |
| Aug 03, 2026 to Aug 12, 2026 (bin_7) | 6.0% |
| Aug 12, 2026 to Oct 26, 2026 (bin_8) | 55.0% |
| Oct 26, 2026 to Jan 10, 2027 (bin_9) | 13.0% |
| Jan 10, 2027 to Mar 26, 2027 (bin_10) | 6.0% |
| Mar 26, 2027 to Jun 10, 2027 (bin_11) | 4.0% |
| After Jun 10, 2027 (bin_12) | 2.0% |
wooley_rhino • run a764864b • $2.92 • 7m9s
Extracted Date Percentile Values: {0.1: 1780272000.0, 1.0: 1780272000.0, 5.0: 1782864000.0, 10.0: 1782864000.0, 15.0: 1782864000.0, 20.0: 1785542400.0, 25.0: 1786579200.0, 30.0: 1786579200.0, 35.0: 1786579200.0, 40.0: 1786579200.0, 45.0: 1786579200.0, 46.0: 1786579200.0, 47.0: 1786579200.0, 48.0: 1786579200.0, 49.0: 1786579200.0, 50.0: 1786579200.0, 51.0: 1786579200.0, 52.0: 1786579200.0, 53.0: 1786579200.0, 54.0: 1786579200.0, 55.0: 1786579200.0, 60.0: 1786579200.0, 65.0: 1786579200.0, 70.0: 1786579200.0, 75.0: 1786579200.0, 80.0: 1786579200.0, 85.0: 1786579200.0, 90.0: 1786579200.0, 95.0: 1786579200.0, 99.0: 1786579200.0, 99.9: 1786579200.0}
Model’s Answer: Looking at this question, I need to forecast when South Korea’s headline CPI might first reach 3.15% YoY within the May 29 - August 12, 2026 resolution window.
Latest Data: April 2026 CPI came in at 2.6% YoY (released May 5-6, 2026), up from 2.2% in March. This represents significant recent momentum but is still ~55 basis points below the 3.15% threshold.
Release Schedule in Window:
Forecast Consensus:
Assumption 1: Institutional forecasts are approximately correct (~20% probability of significant underprediction). If global energy prices spike unexpectedly or KRW weakens substantially, forecasts could be wrong.
Assumption 2: No major policy shocks (utility tariffs, tax changes) (~10% probability of unexpected policy shifts). Such changes could quickly add to headline inflation.
Assumption 3: Base effects remain as projected (~15% probability of unexpected base-effect surprises).
Earlier outcome (June-July 2026): Would require unexpected acceleration driven by energy price shock, FX depreciation, or compounding upside surprises. Officials noted May could “approach or exceed 3%” - but 3.15% requires additional momentum. Probability: ~15-20%
Later outcome (August or beyond): The base case given all forecasters expect sub-3.1% readings through summer 2026. Even risk scenarios don’t clearly breach 3.15%. Probability: ~75-80%
Given:
I estimate:
The median and most of the distribution falls after the resolution deadline, with small probability mass on each of the three possible release dates.
Percentile .1: 2026-06-01 Percentile 1: 2026-06-01 Percentile 5: 2026-07-01 Percentile 10: 2026-07-01 Percentile 15: 2026-07-01 Percentile 20: 2026-08-01 Percentile 25: 2026-08-13 Percentile 30: 2026-08-13 Percentile 35: 2026-08-13 Percentile 40: 2026-08-13 Percentile 45: 2026-08-13 Percentile 46: 2026-08-13 Percentile 47: 2026-08-13 Percentile 48: 2026-08-13 Percentile 49: 2026-08-13 Percentile 50: 2026-08-13 Percentile 51: 2026-08-13 Percentile 52: 2026-08-13 Percentile 53: 2026-08-13 Percentile 54: 2026-08-13 Percentile 55: 2026-08-13 Percentile 60: 2026-08-13 Percentile 65: 2026-08-13 Percentile 70: 2026-08-13 Percentile 75: 2026-08-13 Percentile 80: 2026-08-13 Percentile 85: 2026-08-13 Percentile 90: 2026-08-13 Percentile 95: 2026-08-13 Percentile 99: 2026-08-13 Percentile 99.9: 2026-08-13
Monthly CPI is locked to scheduled embargoed releases and year‑over‑year arithmetic tied to the 2025 base limits how fast the headline can cross 3.15%.
Historical episodes show rapid May–July crossings from an April print near 2.6% are rare, so structural inertia favors no immediate jump.
Upward pressure stems from an oil cost shock and elevated producer prices that create strong pipeline pass‑through toward consumer prices.
Downward pressure stems from an active government petroleum price cap and other stabilization measures that have materially trimmed recent headline inflation.
If the fuel cap is relaxed or oil prices stay high through June, lagged pass‑through makes June the likeliest inflection point for a first reading at or above 3.15%.
If the cap holds and oil softens, base effects and seasonality constrain month‑on‑month gains, making May or July much less likely to reach the threshold.
Key uncertainties are the political decision on the fuel cap, the near‑term oil price path, and exchange‑rate driven import cost pass‑through.
Measurement rounding, publication timing conventions, and any new price controls remain material sensitivities to the exact first‑hit date.
Forecast: June 30, 2026 (median)
Three discrete resolution windows: South Korea releases CPI on June 2 (May data), July 2 (June data), and August 4 (July data), 2026. The effective threshold is 3.2% at one-decimal precision. Only these three dates can resolve the question within the window; after August 12, resolution moves to later months.
Accelerating but constrained trajectory: April 2026 CPI hit 2.6% YoY—a two-year high—with a clear upward trend from 2.0% in January. However, consensus forecasts May at 3.0%, just 20 basis points below the 3.2% threshold. The Bank of Korea’s full-year 2026 forecast of 2.7% average inflation suggests readings will mostly stay below the target.
Favorable base effects offset by moderating oil prices: May 2025’s CPI was only 1.9% YoY (the lowest in the window), creating a mechanical boost for May 2026 YoY comparisons. However, Brent crude fell from ~$108 to $91.75 by late May, weakening the pass-through story. April’s record PPI surge (6.9% YoY, with petroleum +31.9%) typically lags 3–6 months into consumer prices, but government petroleum price caps dampen the effect.
Scenario distribution: Roughly 27% probability May hits 3.2% (June 1 UTC resolution), 22% for June data (July 1 UTC), 14% for July data (August 3 UTC), and 37% that the threshold is never crossed within the window. The 37% tail reflects BOK rate hike expectations, won stabilization, and price control effectiveness keeping inflation in
On what date will South Korea’s consumer price index first be reported at 3.15% year-over-year or higher?
Key figures
Historical context
South Korea has experienced several distinct inflationary cycles over the past decade. Most recently, inflation peaked at 6.3% in July 2022, the highest level since the 1997-1998 Asian Financial Crisis. Following this peak, inflation steadily declined throughout 2024 and 2025, reaching a low of 1.3% in October 2024. The current acceleration in early 2026 represents a sharp reversal of this trend, driven largely by geopolitical instability in the Middle East affecting energy supplies. Historically, the headline CPI has frequently crossed the 3.15% threshold; it was above this level for much of 2022 and 2023. The Bank of Korea’s medium-term inflation target is 2.0%, and the current breach of this target is prompting significant policy concern. Comparisons are being drawn to February 1998, the last time producer prices rose at the current accelerated monthly rate.
Tailwinds
Headwinds
Detailed reasoning
My prediction that South Korea’s consumer price index (CPI) will first be reported at 3.15% or higher on 1st July 2026 is based on a convergence of accelerating macroeconomic trends and specific institutional forecasts.
South Korea’s headline inflation has shown a clear upward trajectory in the first four months of 2026, moving from 2.0% in January and February to 2.2% in March and 2.6% in April. This acceleration is backed by a massive surge in the Producer Price Index (PPI), which rose 2.5% month-over-month in April 2026—the steepest monthly jump since 1998. Historically, PPI serves as a leading indicator for CPI with a lag of one to two months, as rising costs for fuel and raw materials are passed on to consumers.
The primary drivers of this pressure are external. Brent crude oil has risen 43% year-over-year, trading around $91.75 per barrel, while the South Korean won has depreciated significantly to over 1,500 USD/KRW. As a major energy importer, South Korea is highly susceptible to “imported inflation” from both higher dollar-denominated commodity prices and a weaker local currency.
Specific forecasts strongly support a breach in the mid-summer window. For the May 2026 data (to be released June 1/2), the analyst consensus is already 3.0%. While this is close to the 3.15% threshold, I anticipate the June 2026 data (to be released July 1/2) is the most likely first candidate for the breach. Trading Economics’ proprietary forecast specifically projects a 3.2% print for the June period. Furthermore, Capital Economics projects inflation to peak at 3.4% in August 2026.
Since South Korea’s Ministry of Data and Statistics typically reports inflation to one decimal place, the “3.15% or higher” condition is functionally satisfied by a reported value of 3.2%. Given the current 0.235% monthly trend slope and the substantial pipeline pressure from April’s PPI, a 3.2% print in the July 1st release is highly probable. If a breach does not occur then, the August 3rd release (covering July data) serves as a secondary high-probability window, particularly as government fuel tax cuts are scheduled to expire on July 31, 2026, removing a key deflationary buffer.
Key uncertainties
Conclusion