Voting methods

Question 1

Plurality method

Answer 1

The candidate with the most first place votes wins. (Does not have to be majority)

Question 2

Borda count method

Answer 2

Voters rank all candidates from most favorable to least. Each last place vote receives 1 pt, each next to last vote receives 2 pts and so on.
Candidate with most points wins.

Question 3

Plurality-with-elimination method

Answer 3

Candidate with majority (over 50%) of 1st place votes wins. If no candidate receives majority, eliminate the candidate with fewest 1st place votes. Either hold another election or adjust preference table. Continue process until a candidate receives a majority of 1st place votes. That person wins.

Question 4

Pairwise comparison method

Answer 4

Voters rank all candidates. Series of comparisons is made and each of the candidates is compared to each of the other candidates. Preferred candidate in each comparison receives 1 point. In case of a tie, each receives a half point. Candidate with most points wins.

Question 5

Fairness Criteria (4)

Answer 5

1-Majority criterion
2-Head to head criterion
3-Monotonicity criterion
4- Irrelevant Alternatives criterion

Question 6

Majority criterion

Answer 6

If a candidate receives a majority of 1st place votes, then that candidate should win.

Question 7

Head to head criterion (Condorcet)

Answer 7

If a candidate is favored when compared head to head with every other candidate, then that candidate should win.

Question 8

Monotonicity criteria

Answer 8

If a candidate wins an election, in a reelection, the only changes are changes that favor candidate, then that candidate should win reelection.

Question 9

Irrelevant Alternatives criterion

Answer 9

If a candidate wins election, and in recount, the only changes are that one or more of other candidates are removed from ballot, then that candidate should still win election.

Question 10

Arrow’s Impossibility theorem

Answer 10

It is mathematically impossible for any democratic voting system to satisfy each of the four fairness criteria.

Question 11

Preference ballots

Answer 11

Ballots that rank candidates in order of preference

Question 12

What voting method may not satisfy majority criterion?

Answer 12

Borda count method

Question 13

Which voting methods may not satisfy Head-to-head criterion? (3)

Answer 13

Plurality method
Borda count method
Plurality with elimination method

Question 14

Which voting methods may not satisfy monotonicity criterion? (3)

Answer 14

Borda count method
Plurality with elimination method
Pairwise comparison method

Question 15

Which voting methods may not satisfy irrelevant alternatives criterion?

Answer 15

All:
Plurality
Borda count
Plurality with elimination 
Pairwise comparison