U. St. Andrews
Seminar 3 – 14:30
Elections to appoint a pope/president/chief executive take place by repeated ballots over time. We examine a model where an electorate must vote to select an alternative from a finite set of candidates. Starting from the set of candidates that receive some support at the onset, repeated ballots take place over time and the set of candidates decreases over time until one receives (super)majoritarian support. Our motivating example is the election of the pope, and other CEOs in organizations. The analysis applies generally to collective decision where constructing a (super)majoritarian coalition is a dynamic process. We show that identifying two main subsets of alternatives – the electable candidates and the core – is fundamental to determine the outcome of each election. We establish conditions ensuring that a unique core candidates is immediately elected. We also display electorates with a unique core candidate for which the election is delayed, and non-core candidates are elected with positive probability. For elections that are not resolved immediately, we characterize the equilibrium with tools and insights borrowed from the war of attrition literature. Our results provide a strong rationale supporting the Vatican voting rule, i.e., demanding a supermajority just over 2/3.