When you deeply look at any voting method, you will probably find criticism on various approaches. Approval voting is no different. Sadly, evaluating voting methods can get complicated. When it comes to approval voting, voters can vote for one or more candidates. The candidate with the most votes wins.
Approval voting is preferred for elections because
- It is simple
- It favors consensus candidates
- It encourages competition through many candidates
- Removes vote splitting
- Enables voters to support their honest favorite candidates
- It lowers voter utility loss
However, approval voting also has its critics. The following are some of them:
- Approval voting harms voters who approve of additional candidates, hence violating the later-no-charm criteria
The term the later-no-harm simply means that by supporting other candidates, a voter cannot harm the performance of the most-preferred candidates. But a voting method that passes this principle can still hurt a voter who adds other candidates. Approval voting can violate later-no-harm. That’s because approving an additional candidate who is less-preferred creates a direct competition with the most-preferred candidate.
The later-no-harm violation is quite difficult to avoid because of how approval voting operates. While hurting a candidate on your ballot can be annoying, the good thing with approval voting is that you still get the chance to support your favorite candidate [s] because you are allowed to vote for one or more candidates.
- Approval voting deteriorates to bullet voting
In approval voting, the average number of votes per ballot goes up as the number of candidates increase. Fewer candidate options mean that voters choose few candidates and more candidates mean that the voters get to choose more candidates. This is instinctive.
In fact, in the approval voting election, many people tend to bullet vote. The most important part is that the voters get the chance to support many candidates whenever necessary, even when it’s only a fraction of voters who want to. It takes only a fraction of voters who support many candidates to alter the outcome of an election.
- Approval voting is inexpressive since you can only approve or disapprove of a particular candidate
For starters, approval voting is more expressive than plurality voting. Some people are concerned that approval voting does not let them distinguish candidates in more than two groups- i.e., approve or not approve. It is not the same expression as multiple scores or numbered ordering. Approval voting lets you approve each candidate or not. But when there are more candidates, approval voting compensates that flexibility by allowing them to say yes or no for all the candidates.
- Approval voting is unconstitutional, and it violates “one person, one vote”.
The phrase “one person, one vote” is usually used to refer to the weight of votes and not how the votes are expressed. So approval voting doesn’t violate it. If someone votes for multiple candidates, that don’t get an unfair weight for their ballot. Since each voter’s ballot has the same weight, approval voting does not violate “one person, one vote.”