- VERSION 1.09
- Method Common Name: STAR (Score Then Automatic Runoff)
use Vote::Count::Method::STAR; my $tennessee = Vote::Count::Method::STAR->new( BallotSet => read_range_ballots('t/data/tennessee.range.json'), ); my $winner = $tennessee->STAR() ; say $Election->logv();
Implements the STAR method for resolving Range Ballots.
Scores the Range Ballots, then holds a runoff between the two highest scored choices. The method is named for the acronym for Score Then Automatic Runoff.
Conducts and Logs STAR. Returns the winner or 0 in the event of a tie.
The Range Ballot is more complex for voters than the Ranked Choice Ballot. The scoring and runoff are both very simple.
There is significantly less Later Harm with STAR than with other Borda methods. By ranking the preferred choice with the maximum score, and alternate choices very low, the voter is minimizing the later harm impact of those later choices. With 10 choices in regular Borda, the second choice would recieve 90% of the first choice's score, by ranking later choices at the bottom of the scale the impact is much lower.
STAR only meets the Condorcet Loser Criteria. The runoff prevents a Condorcet Loser from winning.
STAR does not meet the Smith and Condorcet Winner Criteria.
More information is needed to know if in practice it performs better than IRV.
STAR should meet Monotonacity. Adding a non-winning choice will have no impact on the outcome unless they can score high enough to reach and lose the runoff phase. Clone handling is dependent on the behavior of the clone group supporters, if they rank the clones far apart, the clone that attracts later support from non-clone supporters is likely to not reach the runoff.
More information is needed to know if Clone handling is good or poor in practice, and whether there is a significant consistency failure of some other type.
Beginning with version 1.08 the STAR() method returns a Hash Ref similar to other Vote::Count Methods. The key 'tie' is true for a tie false otherwise, the key 'winner' contains the winning choice or 0 if there is a tie. When there is a tie an additional key 'tied' contains an Array Ref of the tied choices.
When more than 2 choices are in a tie for the automatic runoff STAR() returns them as a tie.
John Karr (BRAINBUZ) email@example.com
Copyright 2019 by John Karr (BRAINBUZ) firstname.lastname@example.org.
This module is released under the GNU Public License Version 3. See license file for details. For more information on this license visit http://fsf.org.