Condorcetmenetelmät

Condorcet methods are a class of voting systems designed to elect a candidate who would defeat every other candidate in a head-to-head election. This hypothetical candidate is known as the Condorcet winner. The core principle of these methods is to compare all possible pairs of candidates. For each pair, voters indicate their preference. The candidate who wins the majority of pairwise comparisons against all other candidates is declared the winner.

However, a challenge arises when no single candidate wins all their pairwise contests. This situation, known as a Condorcet paradox or cycle, can occur where candidate A beats B, B beats C, and C beats A. In such cases, a Condorcet method needs a predefined tie-breaking rule or a way to resolve the cycle to determine a winner. Different Condorcet methods employ various strategies for resolving these cycles. Examples include the Condorcet-IRV (Instant Runoff Voting) method or the Schulze method, each with its own logic for handling intransitive preferences.

The advantage of Condorcet methods is that they are often considered more representative of voter preferences because they directly assess pairwise strengths. They also satisfy certain desirable criteria, such as the Condorcet criterion (electing the Condorcet winner if one exists). However, their complexity in implementation and the possibility of cycles can be drawbacks. The selection of a specific Condorcet method often depends on how it handles these cycles and the importance placed on various voting theory criteria.