Fairness Criteria
1.
Majority Criterion – If a candidate has a
majority of the first place votes, then that
candidate should be declared the winner.
To violate the majority criterion means a
candidate has a majority of the first place votes,
but that candidate is not declared the winner.
If a candidate has a majority of the first place
votes, then that candidate will be declared the
winner using Plurality, Plurality-with-Elimination,
and the Pairwise Comparison methods.
The Borda Count Method MAY violate the
majority criterion.
2.
Head-to-Head Criterion – If, when compared
head-to-head, one candidate beats every other
candidate, that candidate should be declared the
winner.
To violate the Head-to-Head Criterion means a
candidate beat every other candidate head to
head, but did not win the election.
The Pairwise Comparison Method is the only
method that does not violate the Head-to-Head
Criterion.
All the other methods MAY violate the Head-toHead Criterion.
3.
Monotonicity Criterion – If a candidate wins an
election and in a re-election, the only changes are
in favor of the candidate, that candidate should
win the re-election.
Plurality, Borda Count, and Pairwise Comparison
Methods will always satisfy the Monotonicity
Criterion.
The Plurality with Elimination MAY violate the
Monotonicity Criterion.
4.
Irrelevant Alternatives Criterion – If a
candidate wins an election, and in a re-election, the
losing candidates are removed, then the original
winning candidate should still win.
All four voting methods MAY violate this criterion.