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Inside the Conclave Through Game Theory

17 February, 2026

The papal conclave is often portrayed as a closed, ritualized event. But behind the secrecy lies a voting procedure with clear strategic logic, explains in a new CERGE-EI Blog interview, Jan Zápal (CERGE-EI.

 He introduces the study Electing the pope: Elections by repeated ballots, co-authored with Clara Ponsatí, which uses game theory to explain how repeated voting rounds and a two-thirds majority rule shape outcomes and why these rules can, in principle, last a very long time.

From an economist’s perspective, the conclave becomes a strategic setting. Zápal explains how researchers model it as a “conclave game,” where cardinals have preferences over candidates but also face costs of remaining in the conclave. The study focuses on what kinds of winners the rules tend to produce—especially candidates who are acceptable to enough electors and stable in the sense that no alternative candidate would be clearly preferred by two-thirds of voters.

“One important property… is what we call stability: there is no other candidate whom two thirds… would clearly prefer more than him,” explains Jan Zápal. “We write down a ‘conclave game’ that formally describes who the players are, what they can do, and how they evaluate outcomes.”

A central finding discussed in the interview is that, under certain additional conditions, the existence of a candidate who is both acceptable and stable aligns precisely with a two-thirds election threshold—the very rule that has been used in papal elections for roughly a millennium.

The interview also highlights that conclave-like repeated voting appears in other institutions, from certain party conventions in the United States to procedures used to elect the president of Italy or even the chief conductor of the Berlin Philharmonic. And while economists do not usually measure “legitimacy” directly, Zápal notes that long-standing, stable rules can help confer legitimacy on the eventual outcome —one reason he would not recommend changing the conclave rules.

Read the full interview here.