The right way to read Ranked-choice ballots: not Instant Runoff, but Ranked Pairs-A
Summary: The four linked papers A through D analyze how best to take ranked-choice ballots and choose a single winner. The analysis includes the different incentives each method offers to candidates, causes, and voters, seeking to win, particularly to the tactics of bracketing and strategic nomination; presents examples and proofs of how the different methods perform when voters opinions are described as ranging along more than one political axis; and how the different systems rate against all the various abstract criteria used to assess the worth of election systems. In sum, any tournament method is decisively better than Instant Runoff (also known as the Alternative vote, or the Hare method); and the best of the tournament methods is Ranked Pairs; it is argued that any tournament method better than Ranked Pairs is unlikely to exist, which given its ease of implementation, makes it the best choice if ranked-choice ballots are to be used. Ranked Pairs works whether voters preferences on their ballots are strict, or whether voters are permitted to rank candidates in equal groups. If Ranked Pairs is considered too different from Instant Runoff to adopt, two other runoff methods, the Direct Hybrid and the Benham method, may be used instead.
Description: Paper A covers five key points. (1) Instant Runoff will elect some candidate when a manifestly more representative candidate is running; and it penalizes challengers, in that a challenger's candidacy may not merely fail, but throw the election to a candidate from the opposite end of the political spectrum from that of the challenger. (2) Instant Runoff drives unrepresentative candidates, however ideologically incompatible their views, to ally tactically to destroy representative ones; Condorcet methods in general do not. (3) The statements of how the best of the Condorcet method work are short and are easily understood. (4) The Ranked Pairs method in particular can be decided using paper and pencil, given knowledge only of the margins by which voters prefer one candidate to another. (5) Proper Condorcet methods, like Beatpath and Ranked pairs, guarantee that that a cause shall neither succeed nor fail merely because multiple candidate seek to lead that cause or any other.
