Which G7 leader will leave next?

**Stage 1 — Blind analysis (ignore market prices):**

The evidence pointing to Keir Starmer as the most likely next-to-leave G7 leader is strong. Key proximate triggers are: the resignation of a senior minister (John Healey) that directly undermines the government’s credibility on a summit-focused portfolio (defence); a concrete challenger (Andy Burnham) newly entering Parliament with immediate momentum; contemporaneous media framing that this is a "career-defining decision" with party-level pressure to announce a departure timeline as soon as Monday, 22 June; and the UK’s recent pattern of rapid leadership turnover that lowers the political friction for another exit. Taken together these create a credible, short-window path to Starmer resigning before any of the other listed G7 figures leave office.

Quantitatively, when estimating "who leaves next" among the listed figures, the probability must account for: (a) immediacy and specificity of the threat (Starmer: explicit timeline and internal challenger), (b) vulnerability from recent government events (Healey’s resignation), and (c) comparative stability of the others (no parallel imminent threats for Trump, Macron, Meloni; Mark Carney is an outlier contender). A rational, evidence-based assessment therefore places the UK PM well above a simple plurality: I assign an 88% unconditional probability that the UK Prime Minister will be the next G7 leader to leave office.

Arguments that temper certainty include Starmer's public insistence he "will run, I will stand," which can mobilize loyalists and blunt a challenge; the institutional difficulty of forcing an immediate leader exit depending on parliamentary math and timing; and the possibility that a dramatic but contained ministerial resignation could be politically managed without the leader falling. Those reduce but do not eliminate the high likelihood given the synchronized, multi-front pressure.

**Stage 2 — Market calibration (look at market prices):**

The market currently prices Keir Starmer at ~96.3% (Yes), with the nearest competitor (Donald Trump) at ~4% and others negligible. The market is thus even more convinced than my independent assessment. Reasons the market may be at/above this level:

- *Recency bias and headline amplification:* News cycles that emphasize a Monday deadline and a ministerial resignation can push traders to load heavily on the obvious short-term outcome. Heavy volume (89k contracts) shows many participants have taken that view. - *Binary simplification:* The market’s binary framing (first-out) favors immediate, highly-visible exits; traders overweight immediacy and underweight low-probability long-term shocks (e.g., a sudden U.S. removal or Italian PM exit) that could beat Starmer to being next. - *Liquidity and cascade effects:* As prices climbed, momentum traders and algorithmic participants likely contributed to a feedback loop driving the price toward near-certainty.

Why the market might be slightly overconfident relative to my assessment:

- *Survivorship and resistance risk:* Leaders often survive crises they publicly vow to fight; Starmer could consolidate support quickly and repel the challenge, particularly if Burnham’s mandate or parliamentary math proves insufficient. That plausible path makes a ~8-point gap between my 88% and the market’s 96% defendable. - *Ambiguity in what "leave office" means:* If resignation is narrowly defined (voluntary departure), vs. involuntary removal or electoral defeat over a longer horizon, trader interpretations may have compressed around a short-term reading of current headlines.

Conclusion on calibration: The market correctly identifies Starmer as the dominant frontrunner and prices the event as extremely likely. I believe the true probability is very high but meaningfully below the market price — 88% vs ~96% — because a nontrivial survival path exists and because markets often overshoot on near-term, high-salience narratives. That gap creates a modest implied edge if one could sell Yes or buy No at the current market price, depending on execution costs and event definitions.