Approval Voting - Theory

Theory

Approval voting can be considered a form of range voting, with the range restricted to two values, 0 and 1, or a form of Majority Judgment, with the grades restricted to "Good" and "Poor". Approval voting can also be compared to plurality voting, without the rule that discards ballots which vote for more than one candidate.

By treating each candidate as a separate question, "Do you approve of this person for the job?" approval voting allows each voter to indicate which candidates he or she supports. All votes count equally, and everyone gets the same number of votes: one vote per candidate, either for or against. The final tallies show how many voters support each candidate, and the winner is the candidate whom the most voters support.

Approval voting ballots show, for each office being contested, a list of the candidates running for that seat. Next to each name is a checkbox, or another similar way to mark 'Yes' or 'No' for that candidate. This "check yes or no" approach means approval voting is one of the simplest voting systems to use.

Ballots which mark every candidate the same (whether yes or no) have no effect on the outcome of the election. Each ballot can therefore be viewed as a small "delta" which separates two groups of candidates, or a single-pair of ranks (e.g. if a ballot indicates that A & C are approved and B & D are not, the ballot can be considered to convey the ranking >).

Among single-winner election systems where voters act in their own best interests, approval voting comes closest to reflecting the overall will of the people as measured in terms of minimizing Bayesian regret.