Difference between revisions of "Approval voting"
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'''Approval voting''' is a [[voting system]]
Each voter may vote for as many options as they wish, at most once per option. This is equivalent to saying that each voter may "approve" or "disapprove" each option by voting or not voting for it, and it's also equivalent to voting +1 or 0 in a range voting system.
Approval voting passes a form of the [[monotonicity criterion]], in that voting for a candidate never lowers that candidate's chance of winning. Indeed, there is never a reason for a voter to [[tactical voting|tactically vote]] for a candidate X without voting for all candidates he or she prefers to candidate X.
However, as approval voting does not offer a single method of expressing sincere preferences, but rather a plethora of them, voters are encouraged to analyze their fellow voters' preferences and use that information to decide which candidates to vote for.▼
A good tactic is to vote for every candidate the voter prefers to the leading candidate, and to also vote for the leading candidate if that candidate is preferred to the current second-place candidate. When all voters use this tactic, the [[Condorcet method|Condorcet winner]] is almost certain to win.▼
In the above election, if Chattanooga is perceived as the strongest challenger to Nashville, voters from Nashville will only vote for Nashville, because it is the leading candidate and they prefer no alternative to it. Voters from Chattanooga and Knoxville will withdraw their support from Nashville, the leading candidate, because they do not support it over Chattanooga. The new results would be:
==Effect on elections==
The effect of this system
==Other issues and comparisons==
*It provides less incentive for [[negative campaigning]] than many other systems.
*It allows voters to express [[tolerances versus preferences|tolerances but not preferences]]. Some political scientists consider this a major advantage, especially where acceptable choices are more important than popular choices.
Approval ballots can be of at least four semi-distinct forms. The simplest form is a blank ballot where the names of supported candidates is written in by hand. A more structured ballot will list all the candidates and allow a mark or word to be made by each supported candidate. A more explicit structured ballot can list the candidates and give two choices by each. (Candidate list ballots can include spaces for write-in candidates as well.)
All four ballots are interchangeable. The more structured ballots may aid voters in offering clear votes so they explicitly know all their choices. The Yes/No format can help to detect an "undervote" when a candidate is left unmarked, and allow the voter a second chance to confirm the ballot markings are correct.