Who will be the next UN Secretary-General?

As of September 26, 2026, Costa Rica's Rebeca Grynspan is the most likely next UN Secretary-General at 45 percent. She topped the Security Council's third straw poll with nine encourage votes, the minimum needed, but five members discouraged her and diplomats suspect two of those were veto holders China and Russia.

Evidence cutoff Version 1 of 1By the TPG Forecast Desk, edited by Frank Carrasco, PhD#248fe41b87

Why it matters: The next Secretary-General will run the UN through a period of deep U.S. funding cuts and reform demands, shaping how the organization handles wars, humanitarian aid, nuclear inspections and trade disputes that touch American interests.

TPG forecast: most likely

Rebeca Grynspan

45%

Grynspan leads, but no one has it locked

  • Rebeca Grynspan45%
  • Carolyn Rodrigues Birkett22%
  • Someone else14%
  • Rafael Grossi9%
  • Maria Fernanda Espinosa4%

Kalshi prices Rebeca Grynspan at 54% on Sep 26, 2026

Our odds over timeTPG forecastMarket
0%25%50%75%100%Resolves Dec 31, 2026Sep 26, 2026

Version 1: 45% (range 33% to 57%) · Kalshi 54%

Evidence cutoff Sep 26, 2026 · published Sep 26, 2026 · Grynspan leads, but no one has it locked

This forecast is on its first version. Each update adds a point; old versions are never edited.

The field

Every contender, the odds, and the record on paper. Record facts are sourced; we forecast who is most likely to win, not who should.

01Rebeca Grynspan

Secretary-General of UNCTAD, former Vice President of Costa Rica

20 years in high office

45%

Third straw poll, Sept. 18
9 encourage, 5 discourage[1]
First straw poll, July 30
10 encourage, first place[3]
Prior offices
Vice President of Costa Rica 1994 to 1998; head of Ibero-American General Secretariat 2014 to 2021[14]

The caseShe has led two of three straw polls, reached the nine-vote threshold, and fits both the Latin American rotation and the U.S. demand for a management-minded reformer.

The riskDiplomats suspect China and Russia were among her five discourage votes, and one veto on a colour-coded ballot would end her bid.

02Carolyn Rodrigues Birkett

Guyana's Ambassador to the UN, former Foreign Minister of Guyana

20 years in high office

22%

Second straw poll, Aug. 21
First place, 8 encourage, 3 discourage[2]
First straw poll, July 30
9 encourage[3]
Prior offices
Foreign Minister of Guyana 2008 to 2015; FAO director 2017 to 2020[15]

The caseShe has been within one vote of the lead in every round and topped the August poll, making her the natural fallback if Grynspan is vetoed.

The riskShe has never led on encourage votes when Grynspan did, and a smaller-state ambassador may lack a P5 champion.

03Someone else

Any candidate not listed, including Ivonne A-Baki or a late entrant

14%

The caseDeadlocks have produced late or dark-horse winners before, as in 1981, and diplomats are openly speculating about new entrants.

The riskLate entrants need a veto holder to sponsor them, and none has signalled that it wants to.

04Rafael Grossi

Director General of the International Atomic Energy Agency

13 years in high office

9%

Third straw poll, Sept. 18
5 encourage, 8 discourage[4]
Prior offices
IAEA Director General since 2019; Argentine Ambassador to Austria 2013 to 2019[16]

The caseHe has daily working relationships with all five permanent members through nuclear diplomacy, the profile of a crisis manager Washington says it wants.

The riskHe fell from 7 to 5 encourage votes between August and September, and eight discourages is a steep hole to climb out of.

05Maria Fernanda Espinosa

Former President of the UN General Assembly, former Foreign Minister of Ecuador

4%

Third straw poll, Sept. 18
3 encourage, 6 discourage, 6 no opinion[5]

The caseSix no-opinion votes mean fewer members oppose her than oppose most rivals, which keeps her in play as a compromise.

The riskThree encourage votes is far from the nine needed.

06Macky Sall

Former President of Senegal

15 years in high office · elections 2 won, 0 lost

3%

Third straw poll, Sept. 18
5 encourage, 9 discourage[6]
Prior offices
President of Senegal 2012 to 2024[17]

The caseA former head of state with African backing could become a compromise if the Latin American rotation breaks down.

The riskNine discourage votes is the second-worst showing among remaining candidates, and the rotation favours Latin America.

07Olara Otunnu

Former UN Special Representative for Children and Armed Conflict

3%

Third straw poll, Sept. 18
5 encourage, 7 discourage[7]

The caseA long UN career and a late entry give him room to grow if the leaders stall.

The riskHe is from Africa in a cycle where regional rotation strongly favours Latin America.

The numbers behind the call

9

encourage votes for Grynspan in the Sept. 18 straw poll, the minimum needed for a formal decision[1]

10

encourage votes Grynspan won in the first poll on July 30, against 9 for Rodrigues Birkett[3]

11

encourage votes: the floor Antonio Guterres never fell below in 2016[8]

11

discourage votes for Michelle Bachelet on Sept. 18, before she withdrew[9]

16 rounds

of deadlocked voting in 1981, the last time Latin America won the job[10]

What it means for you

U.S. taxpayers and Congress

Washington has cut UN funding and says it wants a reform-focused manager. A Secretary-General the Trump administration backs, such as a candidate it does not veto, is more likely to deliver budget and staffing cuts that Congress then weighs against future U.S. contributions.

Americans following Middle East and Ukraine diplomacy

The Secretary-General sets the tone for UN mediation and humanitarian operations. A Grynspan or Rodrigues Birkett term would likely emphasize development and multilateral trade; a Grossi term would bring a nuclear-inspection specialist to the top job at a time of Iran tensions.

U.S. exporters and businesses

Grynspan has led the UN's trade and development body since 2021, so her selection would put a trade economist in charge as tariff disputes reshape global commerce. Other candidates would put less emphasis on trade policy.

Latin American diaspora communities in the U.S.

Most of the leading candidates come from Latin America and the Caribbean. The region has held the post only once, from 1982 to 1991, so a win would be a significant symbolic moment for the hemisphere.

The read

Three lenses, always in this order. How the method works.

01

Psychology

What do the decision makers need?

The deciders are the five veto holders, and each needs something different. The United States has said publicly it wants a practical, reform-focused manager who will streamline the organization, which rewards candidates who look like administrators rather than advocates. China and Russia, by past behavior in these selections, protect against anyone they read as too close to Western human rights agendas. Michelle Bachelet's exit fits that pattern: the United States was the only Council member that never met her, and she collapsed to one encourage vote before withdrawing on September 19.

Grynspan's strategy is the low-audience-cost one: an economist running a technical UN agency, with no record of public fights with any permanent member. That makes her acceptable to many and exciting to few, which is exactly the profile that has survived vetoes before. Carolyn Rodrigues Birkett, Guyana's UN ambassador, runs a similar coalition-building campaign from inside the building. For the veto holders, the face-saving move is to avoid being seen blocking the obvious Latin American frontrunner unless they have a clear alternative, and so far none has named one.

02

History

What happened the last times this came up?

Reference class: contested Secretary-General selections since 1981. The early leader in Council voting won in 1991 (Boutros-Ghali, who co-led the straw poll), 2006 (Ban Ki-moon led every poll) and 2016 (Guterres led every round). The early leader lost in 1981, when the United States blocked Salim Ahmed Salim through 16 rounds, and in 1996, when Boutros-Ghali had 14 of 15 votes and was vetoed by Washington alone. That is 3 of 5.

The closest analogue is 1981, the only previous time Latin America won the job. The Council deadlocked, the leaders were vetoed, and a dark horse, Javier Perez de Cuellar, emerged as the compromise. It breaks in one important way: in 1981 the frontrunners were blocked by named superpower objections, while today the veto holders have not yet voted on colour-coded ballots, so nobody knows whether Grynspan's five discourages include a veto. The 2016 comparison cuts against her: Guterres never fell below 11 encourage votes, while Grynspan has shown 10, then 7, then 9.

03

Statistics

Base rate, adjustments, the number.

Start from the base rate: the early straw-poll leader has won 3 of the last 5 contested selections, about 0.60. Adjust down 10 points because Grynspan's lead is thin, with 9 encourages against Guterres's floor of 11 and Ban's unbroken lead, and she lost first place to Rodrigues Birkett in the August round. Adjust down a further 8 points for the reported possibility that two of her five discourages came from China and Russia, since a single veto ends a candidacy.

Adjust up 3 points for regional rotation, which strongly favours a Latin American and Caribbean candidate this cycle, and for Bachelet's withdrawal, which frees votes from Council members that had backed a Latin American woman. That lands at about 0.45. The regulated Kalshi market has Grynspan at 0.54; we are lower because the colour-coded ballots that reveal vetoes have not happened yet, and history shows those ballots are where early leaders fall.

Between the lines

What people spent versus what they said, and what was left out.

Costly signal

Michelle Bachelet, a two-time president of Chile backed by Brazil and Mexico, withdrew the day after the third straw poll, having fallen from six encourage votes in July to one.

Leaving is costly for a candidate of her stature, and it tells us Council members were not treating this as an open conversation. Her backers now have votes to redistribute, and a Latin American candidate is the natural beneficiary.

What was left out

None of the five permanent members has publicly endorsed a candidate or announced a veto, and the Council has not yet moved to colour-coded ballots.

The veto holders are keeping their options open. Silence at this stage lets them avoid the audience cost of openly blocking a woman from the Global South, but it also means the current rankings may not survive the first ballot that separates their votes.

Tone shift

The U.S. State Department said it wants a practical, driven and reform-focused candidate who will restore competent management and streamline the organisation significantly.

That language rewards managers over political figures. It fits an economist who runs a UN agency, or an ambassador who knows the building, better than a former head of state, and it is one reason Bachelet's candidacy never gained Washington's engagement.

Sequencing

Diplomats and analysts say the next straw poll is likely right after the General Assembly's High-Level Week ends on September 28.

Leaders of the 193 member states are in New York this week, which is the best moment to lobby capitals and to float late entrants. If a new name appears before the fourth poll, it signals that some veto holders want an alternative to the current leaders.

History vs the market vs our call
0%25%50%75%100%History: 3 of 5 60% (95% CI 15% to 95%)Kalshi 54%TPG forecast 45%

Our number after adjusting the base rate for what is different this time: 45%. It sits inside the historical interval.

Check our statistics yourself

Reference class
3 of 5 (60%)
Exact 95% CI (Clopper-Pearson)
14.7 to 94.7%
Bayesian 95% credible (uniform prior)
22.3 to 88.2%
Binomial test of our 45%
p = 0.663

Our 45% sits inside the historical interval: the forecast is consistent with how cases like this have gone.

Reproduce in JASP (free, jasp-stats.org)
  1. Download base-rate.csv (one row per case in the reference class, outcome 1 or 0) and open it in JASP.
  2. Frequencies, then Binomial Test. Variable: outcome. Test value: 0.45. Tick Confidence interval. JASP reports the same p value and Clopper-Pearson interval shown here.
  3. Frequencies, then Bayesian Binomial Test, with a Beta(1, 1) prior. The posterior 95% credible interval matches ours.

Reference class: Computed by TPG from the 1981, 1991, 1996, 2006 and 2016 selections as documented on Wikipedia: early leaders won in 1991, 2006 and 2016 and were vetoed in 1981 and 1996.

Base rate

60%

of contested Secretary-General selections since 1981 (3 of 5) were won by the early leader in Council voting[10][11][12][13]

Computed by TPG from the 1981, 1991, 1996, 2006 and 2016 selections as documented on Wikipedia: early leaders won in 1991, 2006 and 2016 and were vetoed in 1981 and 1996. (n = 5)

Closest historical parallels

  • 1981 selection of Javier Perez de Cuellar (1981)

    Alike: The last time the post went to Latin America, after the leading candidates were blocked by veto holders.

    Outcome: After 16 deadlocked rounds, the Council turned to a dark horse who had not campaigned.

    Where it breaks: In 1981 the vetoes were open and repeated; in 2026 no permanent member has shown its hand, so a deadlock is possible but not yet visible.

  • 2016 selection of Antonio Guterres (2016)

    Alike: A crowded, public field with candidate debates, straw polls and pressure for a woman and a particular region.

    Outcome: Guterres led every round and was appointed by acclamation, even though the region favoured that year was Eastern Europe, not his own.

    Where it breaks: Guterres never dropped below 11 encourage votes; Grynspan's support has swung from 10 to 7 to 9, which is a much weaker lead.

How it could play out

Every path we see, sized by probability. Paths where the frontrunner wins add up to 45%.

  • Grynspan clears the colour-coded rounds with no veto Yes45%

    China and Russia shift from discourage to no opinion once colour-coded ballots begin, and the U.S. accepts her management pitch.

  • Rodrigues Birkett overtakes Grynspan No22%

    A permanent member discourages Grynspan on a colour-coded ballot while Rodrigues Birkett, who topped the August poll, draws no P5 opposition.

  • Another declared candidate breaks through No19%

    Grossi, Espinosa, Sall or Otunnu becomes the compromise after the two leaders are blocked.

  • Deadlock produces a late entrant No14%

    Vetoes block the leaders and the Council asks for new names, as it did in 1981 and 1996.

What would change our number

↑

The first colour-coded straw poll shows Grynspan with no discourage from a permanent member

+20 points
↓

A permanent member's discourage vote appears against Grynspan on a colour-coded ballot

-25 points
↓

A new candidate is formally nominated after High-Level Week

-5 to -10 points
↑

Guyana or Costa Rica loses a major regional backer, or Bachelet's former sponsors endorse one of the leaders

+3 to +5 points for the endorsed candidate

TPG 45% vs Kalshi 54%

We are 9 points below the market. Traders price Grynspan's return to first place; we give more weight to the unrevealed P5 votes, because in 1981 and 1996 the leader in open voting was stopped by a single veto once the permanent members' ballots mattered.

Market price recorded September 26, 2026 from Kalshi. Analysis, not investment advice.

How this question resolves

Resolves to the person the UN General Assembly appoints, on the recommendation of the Security Council, as Secretary-General for the term beginning January 1, 2027, succeeding Antonio Guterres. If no appointment is made by December 31, 2026, the question stays open and resolves to whoever is eventually appointed to succeed Guterres.

Closes: December 31, 2026. Judged by: UN General Assembly appointment resolution and UN press release, confirmed by wire reports

Questions people ask

Who will be the next UN Secretary-General?

+

As of September 26, 2026, TPG rates Rebeca Grynspan of Costa Rica, head of the UN trade and development agency UNCTAD, the most likely next Secretary-General at 45 percent. Guyana's UN ambassador Carolyn Rodrigues Birkett is second at 22 percent and IAEA chief Rafael Grossi third at 9 percent. No candidate has yet survived a ballot that reveals the veto holders' votes.

When is the next UN Secretary-General chosen?

+

Antonio Guterres's second term ends on December 31, 2026, and his successor takes office on January 1, 2027. The Security Council has held three secret straw polls, on July 30, August 21 and September 18, with a fourth expected after the General Assembly's High-Level Week. The Council then recommends one name, and the General Assembly formally appoints that person, usually between October and December.

Will the next UN Secretary-General be from Latin America?

+

Probably. Under the informal rule that rotates the job among regional groups, a Latin American and Caribbean candidate is strongly favoured this cycle, and the top three candidates in the latest straw poll all come from the region. The region has held the post only once, under Javier Perez de Cuellar from 1982 to 1991. We give a Latin American or Caribbean candidate roughly an 85 percent chance.

Why did Michelle Bachelet drop out of the UN Secretary-General race?

+

The former Chilean president withdrew on September 19, 2026, a day after the third straw poll gave her one encourage vote and 11 discourage votes, down from six encourages in July. Chile's new government under President Jose Antonio Kast had withdrawn its support in March, and PassBlue reported the United States was the only Council member that never met with her.

Can the U.S. veto the UN Secretary-General pick?

+

Yes. Any of the five permanent Security Council members, the United States, China, Russia, Britain and France, can block a candidate. The United States did so in 1981 against Salim Ahmed Salim and in 1996 against Boutros Boutros-Ghali, who had 14 of 15 votes. Colour-coded ballots later in the process reveal which discourage votes come from veto holders.

Sources

Every source is dated on or before the September 26, 2026 evidence cutoff. Nothing published later was used.

  1. [1]Third Straw Poll for UN Secretary-General Race Shows No Consensus. PassBlue, Sep 18, 2026.

    “Rebeca Grynspan of Costa Rica received the most "encourage" votes, or nine, according to diplomats, as the results are not made public.”

  2. [2]Third Straw Poll for UN Secretary-General Race Shows No Consensus. PassBlue, Sep 18, 2026.

    “topped the most-previous straw poll, on Aug. 21, by placing first with eight encourage votes, three discouragements and four no opinion.”

  3. [3]Third Straw Poll for UN Secretary-General Race Shows No Consensus. PassBlue, Sep 18, 2026.

    “Grynspan led the first round on July 30, with 10 encourage, while Rodrigues Birkett received nine.”

  4. [4]Third Straw Poll for UN Secretary-General Race Shows No Consensus. PassBlue, Sep 18, 2026.

    “fell to five encourage votes in Friday's poll. He received eight discourage votes and two no opinions.”

  5. [5]Third Straw Poll for UN Secretary-General Race Shows No Consensus. PassBlue, Sep 18, 2026.

    “received three encourage votes, six discourage and six no opinions.”

  6. [6]Third Straw Poll for UN Secretary-General Race Shows No Consensus. PassBlue, Sep 18, 2026.

    “Macky Sall, a former president of Senegal, recorded five encourage votes, nine discourages and one no opinion.”

  7. [7]Third Straw Poll for UN Secretary-General Race Shows No Consensus. PassBlue, Sep 18, 2026.

    “a former UN special representative for children and armed conflict, also received five encourage votes, along with seven discourage and three no opinions.”

  8. [8]Third Straw Poll for UN Secretary-General Race Shows No Consensus. PassBlue, Sep 18, 2026.

    “his straw poll results never dropped below 11 "encourage" votes at any point in the race”

  9. [9]Michelle Bachelet exits UN chief race after low poll support. Al Jazeera, Sep 20, 2026.

    “she received just one "encourage" vote, 11 "discourage" votes and three "no opinion" votes, compared with six encouraging votes in July and two in August.”

  10. [10]1981 United Nations Secretary-General selection. Wikipedia, Sep 26, 2026.

    “the selection deadlocked through 16 rounds of voting as China vetoed Waldheim and the United States voted against Salim.”

  11. [11]1991 United Nations Secretary-General selection. Wikipedia, Sep 26, 2026.

    “Boutros Boutros-Ghali of Egypt and Bernard Chidzero of Zimbabwe led the straw poll with 10 votes each.”

  12. [12]1996 United Nations Secretary-General selection. Wikipedia, Sep 26, 2026.

    “The resolution received 14 votes in favor, 1 vote against, and no abstentions. The only negative vote was the promised U.S. veto.”

  13. [13]2016 United Nations Secretary-General selection. Wikipedia, Sep 26, 2026.

    “led the polling in every round, finishing the last round with 13 'encourage' votes, 0 'discourage' votes, and 2 abstentions.”

  14. [14]2026 United Nations Secretary-General selection. Wikipedia, Sep 26, 2026.

    “Second Vice President of Costa Rica (1994-1998) Secretary-General of the Ibero-American General Secretariat (2014-2021)”

  15. [15]2026 United Nations Secretary-General selection. Wikipedia, Sep 26, 2026.

    “Minister of Foreign Affairs of Guyana (2008-2015) Director at the UN Food and Agriculture Organization (2017-2020)”

  16. [16]2026 United Nations Secretary-General selection. Wikipedia, Sep 26, 2026.

    “Argentine Ambassador to Austria (2013-2019) Director General of the International Atomic Energy Agency (2019-present)”

  17. [17]2026 United Nations Secretary-General selection. Wikipedia, Sep 26, 2026.

    “African Group President of Senegal (2012-2024) Chairperson of the African Union (2022-2023)”

  18. [18]2026 United Nations Secretary-General selection. Wikipedia, Sep 26, 2026.

    “a candidate from the Latin American and Caribbean Group (GRULAC) is strongly favoured.”

  19. [19]UN Security Council holds third straw poll in race for next Secretary General ahead of UNGA. The National, Sep 18, 2026.

    “The United States is looking for a practical, driven and reform-focused candidate who will safeguard the valuable contributions of member states”

Version history and integrity

Published forecasts are never edited. When the evidence changes we publish a new version beside the old one, each locked with a sha256 hash of its full contents. When this question resolves it is scored in public on our track record.

VersionCutoffForecastLock hash
v1Sep 26, 2026Rebeca Grynspan 45% frontrunner248fe41b8758456556f57d930bfe6d0572462b99a8bae640e91d56706b0e492a

Download every forecast: JSON or CSV (CC BY 4.0). Public sources only. Analysis, not investment or legal advice.

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