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What first round vote share will Iliana Iotova win in the 2026 Bulgarian Presidential election?

post 45262·question 45452·numeric·metaculus-cup-fall-2026·2026-09-07T18:07:22.499565·view on metaculus ↗

46.5

Submitted p50

weighted_average

Fermi logic

politics

Domain

Plan 32.95s

Sub-questions define nested thresholds (>=50%, >=40%) whose probabilities anchor the CDF of Iotova's vote share, while the endorsement and final-poll sub-questions shift the center of mass between a ~45-52% 'united pro-Radev incumbent' scenario and a ~28-38% 'fragmented field/rival candidate' scenario; the weighted blend informs the median and tails of the numeric distribution.

Sub-questions (4)

sq1

Will Iliana Iotova win at least 50% of the vote in the first round on October 25, 2026 (i.e., win outright without a runoff)?

The key upper-tail question. Radev won 49.4% in 2021 first round as a massively popular incumbent; Iotova has the highest approval among officials and polls near 50%, but Bulgaria's fragmented field (GERB, PP-DB, Vazrazhdane, DPS, BSP candidates) historically pulls frontrunners below 50%.

w=0.30

sq2

Will Iliana Iotova win at least 40% of the first-round vote?

Central-mass threshold. Historically strong incumbents/consensus candidates (Plevneliev 2011 ~40%, Zhelev 1992 ~45%, Stoyanov 1996 ~44%) landed in this band; determines whether the distribution centers in the 40s or 30s.

w=0.25

sq3

Will Iotova run with the formal backing (or de facto non-opposition) of Rumen Radev's Progressive Bulgaria party, with no rival candidate fielded from the pro-Radev camp?

Radev's party just swept parliamentary elections; if Progressive Bulgaria endorses her and does not split the vote, her share should be far higher than if Radev fields his own candidate or stays neutral, which would likely cap her in the 20s-30s.

w=0.25

sq4

Will the final pre-election polls (October 2026) show Iotova at or above 45% among decided voters in the first round?

Polling trajectory from the ~50% in July through the campaign is the most direct predictor; Bulgarian polls have historically been reasonably accurate for presidential frontrunners (Radev 2021 polled high 40s and got 49.4%).

w=0.20

Tool requests (4)

claude_news sq1, sq2, sq3, sq4 {"brief": "Find the latest polling for the October 25, 2026 Bulgarian presidential election first round: Iliana Iotova\u0027s projected vote share (Alpha Research, Gallup International Balkan, Market Links, Trend, Myara), the full list of registered candidates (GERB, PP-DB, Vazrazhdane, DPS, BSP, Progressive Bulgaria), whether Rumen Radev\u0027s Progressive Bulgaria formally endorsed Iotova or fielded its own candidate, and any campaign controversies affecting her support.", "max_searches": 5, "question_title": "What first round vote share will Iliana Iotova win in the 2026 Bulgarian Presidential election?"}

article_search sq3, sq4 {"lookback_days": 90, "queries": ["Iotova presidential election poll Bulgaria", "Bulgaria presidential candidates October 2026 GERB Vazrazhdane candidate", "Radev Progressive Bulgaria endorse Iotova president"]}

wikipedia_lookup sq1, sq2 {"queries": ["2026 Bulgarian presidential election", "2021 Bulgarian presidential election", "2016 Bulgarian presidential election", "2011 Bulgarian presidential election", "Iliana Iotova"]}

code_execution sq1, sq2 {"code": "import numpy as np\n# Historical first-round shares of leading candidate in Bulgarian presidential elections\nhist = {1992:44.7, 1996:44.1, 2001:36.4, 2006:64.1, 2011:40.1, 2016:25.4, 2021:49.4}\nv = np.array(list(hist.values()))\nprint(\u0027Historical frontrunner first-round shares:\u0027, hist)\nprint(\u0027mean %.1f median %.1f std %.1f\u0027 % (v.mean(), np.median(v), v.std()))\nprint(\u0027share \u003e=50%%: %.2f, \u003e=40%%: %.2f\u0027 % ((v\u003e=50).mean(), (v\u003e=40).mean()))\n# Scenario mixture: poll ~48-50% with ~10% undecided; polling error sd ~5pts; fragmentation drag\nrng = np.random.default_rng(0)\nN=50000\nendorsed = rng.random(N) \u003c 0.75 # P(Radev camp backs her, no rival)\nbase = np.where(endorsed, 47.0, 33.0)\nshare = base + rng.normal(0, 6.0, N)\nshare = np.clip(share, 5, 90)\nfor q in [5,10,25,50,75,90,95]:\n print(\u0027p%d: %.1f\u0027 % (q, np.percentile(share,q)))\nprint(\u0027P(\u003e=50): %.3f P(\u003e=40): %.3f P(\u003e=30): %.3f\u0027 % ((share\u003e=50).mean(), (share\u003e=40).mean(), (share\u003e=30).mean()))", "description": "Base-rate analysis of Bulgarian presidential first-round frontrunner vote shares and a simple distribution for Iotova conditioned on poll level and field fragmentation"}

Research 25.34s · 4 tool(s) · 0 error(s)

claude_news ok 16 citations 25.34s

article_search ok 21 articles 0.54s

wikipedia_lookup ok 3 pages 1.3s

code_execution ok Base-rate analysis of Bulgarian presidential first-round fro 0.15s

Cross-market signals

## Cross-Market Signals

### Polymarket
- "Will Luiz Inácio Lula da Silva win the 2026 Brazilian presidential election?" → Yes: 0.58, Volume: $9.9M
- "Will Augusto Cury win the 2026 Brazilian presidential election?" → Yes: 0.02, Volume: $4.3M
- "Will Flávio Bolsonaro win the 2026 Brazilian presidential election?" → Yes: 0.39, Volume: $9.8M
- "Will Pablo Marçal win the 2026 Brazilian presidential election?" → Yes: 0.00, Volume: $3.8M
- "Will Geraldo Alckmin win the 2026 Brazilian presidential election?" → Yes: 0.00, Volume: $6.2M
- "Will Renan Santos win the 2026 Brazilian presidential election?" → Yes: 0.01, Volume: $12.8M
- "Will Donald Trump win the 2028 US Presidential Election?" → Yes: 0.02, Volume: $10.1M

Evidence Synthesis 34.41s · 11 items

Direction mix: UP 5 DOWN 2 NEUTRAL 4

sq1 code_execution MODERATE cred 85 DOWN DATED

Bulgarian first-round frontrunners 1992-2021 averaged 43.5% (median 44.1%); only one of seven (2006, incumbent Parvanov, 64.1%) exceeded 50%.

sq2 code_execution MODERATE cred 85 UP DATED

Five of seven historical Bulgarian first-round frontrunners scored at least 40%; the two exceptions were 2001 (36.4%) and 2016 (25.4%).

sq1 code_execution MODERATE cred 85 UP DATED

Incumbent presidents seeking re-election (Parvanov 2006: 64.1%, Radev 2021: 49.4%) posted the two highest first-round shares in Bulgarian history.

sq1 wikipedia_lookup MODERATE cred 90 DOWN DATED

Both the 2016 and 2021 presidential elections required runoffs; no candidate won outright in the first round.

sq4 question_description MODERATE cred 60 UP DATED

A late June/early July 2026 poll found around half of respondents likely to support Iotova for president.

sq4 question_description MODERATE cred 70 UP RECENT

An August 2026 IBNA-reported poll showed Iotova with the highest approval rating among Bulgaria's senior state officials.

sq3 question_description STRONG cred 92 NEUTRAL DATED

Iotova formally announced her candidacy on July 24, 2026 via BTA, citing the support of many people in Bulgaria.

sq3 question_description MODERATE cred 90 UP DATED

Iotova served nine years as Radev's vice president; Radev's Progressive Bulgaria now governs with Radev as prime minister.

sq3 article_search WEAK cred 35 NEUTRAL VERY_RECENT

Article search (June-Sept 2026) surfaced no reports of a Progressive Bulgaria endorsement or rival pro-Radev candidate; results were almost entirely non-Bulgarian.

sq1 code_execution WEAK cred 40 NEUTRAL VERY_RECENT

A simple model blending base rates and polling gave P(>=50%)=0.23, P(>=40%)=0.69, median 44.5%.

sq1 wikipedia_lookup STRONG cred 90 NEUTRAL RECENT

Election is scheduled for 25 October 2026 with Iotova eligible and declared; no indication of postponement.

Information gaps

No data on declared opposition candidates (GERB, PP-DB, Vazrazhdane, DPS) or field fragmentation
No confirmation of Progressive Bulgaria's formal endorsement or a rival pro-Radev candidate
No head-to-head polls giving Iotova's first-round share among decided voters
No data on undecided share or expected turnout in current polls

Key uncertainties

Whether Radev/Progressive Bulgaria back Iotova or field their own candidate
Degree of opposition consolidation behind a single strong challenger
Durability of Radev government honeymoon through October
Gap between 'likely to support' polling and actual first-round vote share

Forecast 33.38s · opus, secondary

Rationale

(a) Roughly 1-2 months remain until the 25 October 2026 first round, so the field will crystallize shortly but the campaign itself is short. (b) Status quo: a late-June/early-July poll had ~half of all respondents likely to back Iotova, she has the highest approval of any senior official, and she is the natural candidate of Radev's dominant Progressive Bulgaria; translated to decided voters that points to roughly 45-52%. (c) If the Radev-government honeymoon and her approval hold, she lands near the Radev-2021 analogue (49.4%) against a fragmented opposition (GERB, DPS-Peevski, Vazrazhdane, PP-DB each fielding someone). (d) Base rates: Bulgarian frontrunners average ~44% in round one, only Parvanov 2006 cleared 50%, and incumbents posted the two best results; a blended model gave median 44.5% and P(>=50%) ~0.23, which I nudge upward because her polling and party alignment resemble 2006/2021 more than typical years. (e) Low scenario (~p10): Radev's honeymoon fades by autumn, opposition consolidates behind one strong GERB/PP-DB-backed challenger, a pro-Radev or populist rival (e.g., Vazrazhdane) siphons protest votes, and 'likely to support' softens to ~38-40% actual. (f) High scenario (~p90): the opposition stays hopelessly fragmented, Progressive Bulgaria fully mobilizes its parliamentary-election machine, and she wins outright with 53-56%, similar to Parvanov's 2006 rout. I center near 47% with wide tails reflecting the unknown field and translation from approval to vote share.

Evidence brief shown to forecaster

1. [sq1 | code_execution | MODERATE cred 85 | DOWN | DATED] Bulgarian first-round frontrunners 1992-2021 averaged 43.5% (median 44.1%); only one of seven (2006, incumbent Parvanov, 64.1%) exceeded 50%.
2. [sq2 | code_execution | MODERATE cred 85 | UP | DATED] Five of seven historical Bulgarian first-round frontrunners scored at least 40%; the two exceptions were 2001 (36.4%) and 2016 (25.4%).
3. [sq1 | code_execution | MODERATE cred 85 | UP | DATED] Incumbent presidents seeking re-election (Parvanov 2006: 64.1%, Radev 2021: 49.4%) posted the two highest first-round shares in Bulgarian history.
4. [sq1 | wikipedia_lookup | MODERATE cred 90 | DOWN | DATED] Both the 2016 and 2021 presidential elections required runoffs; no candidate won outright in the first round.
5. [sq4 | question_description | MODERATE cred 60 | UP | DATED] A late June/early July 2026 poll found around half of respondents likely to support Iotova for president.
6. [sq4 | question_description | MODERATE cred 70 | UP | RECENT] An August 2026 IBNA-reported poll showed Iotova with the highest approval rating among Bulgaria's senior state officials.
7. [sq3 | question_description | STRONG cred 92 | NEUTRAL | DATED] Iotova formally announced her candidacy on July 24, 2026 via BTA, citing the support of many people in Bulgaria.
8. [sq3 | question_description | MODERATE cred 90 | UP | DATED] Iotova served nine years as Radev's vice president; Radev's Progressive Bulgaria now governs with Radev as prime minister.
9. [sq3 | article_search | WEAK cred 35 | NEUTRAL | VERY_RECENT] Article search (June-Sept 2026) surfaced no reports of a Progressive Bulgaria endorsement or rival pro-Radev candidate; results were almost entirely non-Bulgarian.
10. [sq1 | code_execution | WEAK cred 40 | NEUTRAL | VERY_RECENT] A simple model blending base rates and polling gave P(>=50%)=0.23, P(>=40%)=0.69, median 44.5%.
11. [sq1 | wikipedia_lookup | STRONG cred 90 | NEUTRAL | RECENT] Election is scheduled for 25 October 2026 with Iotova eligible and declared; no indication of postponement.

## Cross-Market Signals

### Polymarket
- "Will Luiz Inácio Lula da Silva win the 2026 Brazilian presidential election?" → Yes: 0.58, Volume: $9.9M
- "Will Augusto Cury win the 2026 Brazilian presidential election?" → Yes: 0.02, Volume: $4.3M
- "Will Flávio Bolsonaro win the 2026 Brazilian presidential election?" → Yes: 0.39, Volume: $9.8M
- "Will Pablo Marçal win the 2026 Brazilian presidential election?" → Yes: 0.00, Volume: $3.8M
- "Will Geraldo Alckmin win the 2026 Brazilian presidential election?" → Yes: 0.00, Volume: $6.2M
- "Will Renan Santos win the 2026 Brazilian presidential election?" → Yes: 0.01, Volume: $12.8M
- "Will Donald Trump win the 2028 US Presidential Election?" → Yes: 0.02, Volume: $10.1M

Information gaps:
  - No data on declared opposition candidates (GERB, PP-DB, Vazrazhdane, DPS) or field fragmentation
  - No confirmation of Progressive Bulgaria's formal endorsement or a rival pro-Radev candidate
  - No head-to-head polls giving Iotova's first-round share among decided voters
  - No data on undecided share or expected turnout in current polls

Key uncertainties:
  - Whether Radev/Progressive Bulgaria back Iotova or field their own candidate
  - Degree of opposition consolidation behind a single strong challenger
  - Durability of Radev government honeymoon through October
  - Gap between 'likely to support' polling and actual first-round vote share

Raw forecast prompt

You are an elite superforecaster. Produce a probability distribution over the answer to this Metaculus numeric question.

## Question
What first round vote share will Iliana Iotova win in the 2026 Bulgarian Presidential election?

## Description / Resolution Criteria
## Description
[Iliana Iotova](https://en.wikipedia.org/wiki/Iliana_Iotova) became [Bulgaria's first female president](https://www.bta.bg/en/news/bulgaria/1049637-iliana-iotova-becomes-bulgaria-s-acting-president-after-constitutional-court-rul) on January 23, 2026 after Rumen Radev resigned. Radev would months later form the Progressive Bulgaria party, win parliamentary elections and [become Prime Minister](https://www.politico.eu/article/rumen-radev-sweeps-into-power-bulgaria-names-new-prime-minister/).

Bulgaria's next presidential elections are scheduled for October 2026. [A poll](https://m.novinite.com/articles/239845/Poll+Puts+Iliana+Yotova+Ahead+in+Bulgaria's+Presidential+Race) conducted in late June and early July 2026 showed "around half of respondents said they would be likely to support her". Then on July 24, 2026, [Iotova announced](https://www.bta.bg/en/news/bulgaria/1173487-head-of-state-iliana-iotova-to-run-for-president-in-upcoming-election) her intention to run for presidency because she believes she has "the support of many people in Bulgaria". President Iotova has [the highest approval rating](https://www.ibnaeu.com/en/2026/08/07/rumen-radev-first-100-days-government-bulgaria-poll/) among Bulgaria's senior state officials.&#x20;

Iotova served as the country's Vice President from January 2017 until her ascent to presidency.

## Resolution Criteria
This question will resolve as the percentage vote share received by Iliana Iotova in the first round of the Bulgarian presidential election scheduled to be held on October 25, 2026, as declared by the [Bulgarian Central Election Commission](https://results.cik.bg/).

## Fine Print
If the election is postponed or cancelled such that no result is declared on or before December 31, 2026, this question will be **annulled**.

## Range
The answer must be a number in [35, 55] (units: %).

## Sub-question decomposition (planner)
- (w=0.30) Will Iliana Iotova win at least 50% of the vote in the first round on October 25, 2026 (i.e., win outright without a runoff)?  — The key upper-tail question. Radev won 49.4% in 2021 first round as a massively popular incumbent; Iotova has the highes
- (w=0.25) Will Iliana Iotova win at least 40% of the first-round vote?  — Central-mass threshold. Historically strong incumbents/consensus candidates (Plevneliev 2011 ~40%, Zhelev 1992 ~45%, Sto
- (w=0.25) Will Iotova run with the formal backing (or de facto non-opposition) of Rumen Radev's Progressive Bulgaria party, with no rival candidate fielded from the pro-Radev camp?  — Radev's party just swept parliamentary elections; if Progressive Bulgaria endorses her and does not split the vote, her 
- (w=0.20) Will the final pre-election polls (October 2026) show Iotova at or above 45% among decided voters in the first round?  — Polling trajectory from the ~50% in July through the campaign is the most direct predictor; Bulgarian polls have histori

## Synthesized evidence
1. [sq1 | code_execution | MODERATE cred 85 | DOWN | DATED] Bulgarian first-round frontrunners 1992-2021 averaged 43.5% (median 44.1%); only one of seven (2006, incumbent Parvanov, 64.1%) exceeded 50%.
2. [sq2 | code_execution | MODERATE cred 85 | UP | DATED] Five of seven historical Bulgarian first-round frontrunners scored at least 40%; the two exceptions were 2001 (36.4%) and 2016 (25.4%).
3. [sq1 | code_execution | MODERATE cred 85 | UP | DATED] Incumbent presidents seeking re-election (Parvanov 2006: 64.1%, Radev 2021: 49.4%) posted the two highest first-round shares in Bulgarian history.
4. [sq1 | wikipedia_lookup | MODERATE cred 90 | DOWN | DATED] Both the 2016 and 2021 presidential elections required runoffs; no candidate won outright in the first round.
5. [sq4 | question_description | MODERATE cred 60 | UP | DATED] A late June/early July 2026 poll found around half of respondents likely to support Iotova for president.
6. [sq4 | question_description | MODERATE cred 70 | UP | RECENT] An August 2026 IBNA-reported poll showed Iotova with the highest approval rating among Bulgaria's senior state officials.
7. [sq3 | question_description | STRONG cred 92 | NEUTRAL | DATED] Iotova formally announced her candidacy on July 24, 2026 via BTA, citing the support of many people in Bulgaria.
8. [sq3 | question_description | MODERATE cred 90 | UP | DATED] Iotova served nine years as Radev's vice president; Radev's Progressive Bulgaria now governs with Radev as prime minister.
9. [sq3 | article_search | WEAK cred 35 | NEUTRAL | VERY_RECENT] Article search (June-Sept 2026) surfaced no reports of a Progressive Bulgaria endorsement or rival pro-Radev candidate; results were almost entirely non-Bulgarian.
10. [sq1 | code_execution | WEAK cred 40 | NEUTRAL | VERY_RECENT] A simple model blending base rates and polling gave P(>=50%)=0.23, P(>=40%)=0.69, median 44.5%.
11. [sq1 | wikipedia_lookup | STRONG cred 90 | NEUTRAL | RECENT] Election is scheduled for 25 October 2026 with Iotova eligible and declared; no indication of postponement.

## Cross-Market Signals

### Polymarket
- "Will Luiz Inácio Lula da Silva win the 2026 Brazilian presidential election?" → Yes: 0.58, Volume: $9.9M
- "Will Augusto Cury win the 2026 Brazilian presidential election?" → Yes: 0.02, Volume: $4.3M
- "Will Flávio Bolsonaro win the 2026 Brazilian presidential election?" → Yes: 0.39, Volume: $9.8M
- "Will Pablo Marçal win the 2026 Brazilian presidential election?" → Yes: 0.00, Volume: $3.8M
- "Will Geraldo Alckmin win the 2026 Brazilian presidential election?" → Yes: 0.00, Volume: $6.2M
- "Will Renan Santos win the 2026 Brazilian presidential election?" → Yes: 0.01, Volume: $12.8M
- "Will Donald Trump win the 2028 US Presidential Election?" → Yes: 0.02, Volume: $10.1M

Information gaps:
  - No data on declared opposition candidates (GERB, PP-DB, Vazrazhdane, DPS) or field fragmentation
  - No confirmation of Progressive Bulgaria's formal endorsement or a rival pro-Radev candidate
  - No head-to-head polls giving Iotova's first-round share among decided voters
  - No data on undecided share or expected turnout in current polls

Key uncertainties:
  - Whether Radev/Progressive Bulgaria back Iotova or field their own candidate
  - Degree of opposition consolidation behind a single strong challenger
  - Durability of Radev government honeymoon through October
  - Gap between 'likely to support' polling and actual first-round vote share

## Required pre-forecast walkthrough

Before giving percentiles, address these explicitly in your rationale:
  (a) The time left until the question resolves.
  (b) The outcome if NOTHING changes from today (the status quo value).
  (c) The outcome if the CURRENT TREND continues.
  (d) The expectations of experts / markets / base rates.
  (e) A plausible scenario that produces a LOW outcome (near p10).
  (f) A plausible scenario that produces a HIGH outcome (near p90).

## Calibration guidance

- **Be humble about tails.** Good forecasters set WIDE 90/10 intervals to account for unknown unknowns. Narrow tails get punished by the log score far more than slightly-biased medians.
- **Status quo anchoring.** The p50 should be close to the status quo value unless you have strong evidence of a trend.
- Don't pile mass at one value — if you're tempted, widen the spread by 20-50%.
- **Anchor on markets/experts.** If liquid market prices, analyst forecasts, or community percentiles appear in the evidence, center your distribution on them and widen — don't override a liquid market without specific evidence it lacks.
- **Relative-return / spread questions ("how much will X's return exceed Y's").** A near-zero median is usually right, but size the TAILS to the more VOLATILE leg, not to a generic 2-3pp spread. Two broad equity indices (e.g. Nasdaq-100 vs S&P 500) do stay within roughly ±2-3pp over a two-week window. But when one leg is a commodity (crude oil, gold) or a single high-beta stock (e.g. Nvidia), the two-week realized spread regularly reaches ±10pp or more — crude-vs-equity spreads have hit ±18pp. In those cases set p10/p90 to at least ±10pp (±15pp or wider for oil) while keeping the median near the status-quo spread; the 2-3pp intuition applies only to index-vs-index.
- **Heavy-tailed one-off magnitudes (opening-weekend box office, product-launch or debut numbers).** Pre-event tracking for these routinely misses by ±40% or more, and results land both far above and far below the consensus. Do NOT treat the displayed [min, max] range as the plausible range or clamp p10/p90 to its edges: the outcome can fall outside the range in either direction (recent opening weekends resolved ~7% above a displayed ceiling in one case and roughly half the displayed floor in another). Set p10/p90 wide enough that a 2x-or-0.5x surprise versus your central estimate still lands inside the interval, and when concrete current tracking disagrees with historical/franchise base rates, weight the tracking.

## Output

Return ONLY valid JSON, no markdown fences:

{
  "rationale": "<address (a) through (f) above, then state your distribution — 6-10 sentences total>",
  "p10": <number>,
  "p25": <number>,
  "p50": <number>,
  "p75": <number>,
  "p90": <number>
}

Percentiles MUST be in non-decreasing order (p10 <= p25 <= p50 <= p75 <= p90).