Selected topics in finite mathematics/Approval voting

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[Give a very very brief overview?]

Objectives[edit | edit source]

The goal here is to determine the winner in an individual election based upon who has the most votes.

Details[edit | edit source]

Approval voting is a voting scheme where each voter marks whether or not they approve of each candidate, instead of ranking the candidates. The candidate that has the highest approval is declared the winner.

[Give a prose-explanation approval voting?]

Examples[edit | edit source]

100 people have approval of three candidates as shown below. An "X" means they approve. Who will be elected?

Candidate 1 X X X
Candidate 2 X X X
Candidate 3 X X X
Number of Ballots 40 25 20 15

Candidate 1: 75

Candidate 2: 60

Candidate 3: 85

The majority of the 100 people are satisfied with Candidate 3. Because candidate 3 has the highest approval, they are the winner.

Nonexamples[edit | edit source]

[Give some non-examples of approval voting?]

FAQ[edit | edit source]

Homework[edit | edit source]

Suppose three candidates are in an election. 70% of the population would be satisfied with candidate A, while 60% would be satisfied with candidate B, and 50% would be satisfied with candidate C. Using approval voting, which candidate would win?


Compare approval voting to plurality. What advantages does approval voting have? What disadvantages does approval voting have?


A X X
B X X
C X X
D X X
Number of votes  4   3   3 
Consider the approval table above. Who wins, under approval voting?