Wasted vote
In electoral systems, a wasted vote is any vote cast that is not "used" to elect a winner, and so is not represented in the outcome. However, the term is vague and ill-defined, having been used to refer to a wide variety of unrelated concepts and metrics. The analysis depends on the way a "wasted vote" is defined.
Wasted votes seldom affect each party equally irrespective of the system that produces them. More wasted votes for one party and fewer for another create a chamber of elected members that is not proportional. Distortions produced by wasted votes work against the aim of fairly reflecting the wishes of the electorate. However, a system that produces wasted votes may prevent instability caused by many parties being elected to the legislature.
Terminology
There are at least two different types of wasted votes:- Lost votes are votes that make no impact on which candidates are elected. These votes do not actually elect anyone. They are cast for defeated candidates.
- Excess votes are votes that a successful candidate receives above and beyond what they needed to be elected.
The wasted vote share is calculated as:
where is the vote share of unrepresented party and is the overall number of unrepresented parties. The lost vote can be given as a percentage of the total number of votes or as the absolute number of votes.
By electoral system
Plurality voting
In plurality systems, the ballots of voters outside of the plurality may be considered "wasted" as they do not contribute to the outcome. The proportion of votes that are wasted in a district may exceed half of votes cast, sometimes as much as 82 percent. This situation sometimes leads to an overall result where more votes are cast for defeated candidates than are used to elect anyone.Proportional representation
In proportional electoral systems, representatives are elected in rough proportion to voter preferences, each being elected by about the same proportion of votes, resulting in almost all votes being used to elect someone. This results in fewer wasted votes than in plurality voting. This also results in each party being represented roughly in proportion to its share of the overall popular vote.In list PR systems, this relationship is established based on party votes. In single transferable voting, most winners in each district are elected by the same number of votes, and the rest of the successful candidates are elected by about that same number of votes, even if that number does not meet the quota. Under both list PR and STV systems, 80 to 90 percent of votes or more are used to elect the winners. That rule holds true both at the district level and overall.
Thresholds and lost votes
In proportional representation, wasted votes increase with a higher electoral threshold. Higher electoral thresholds may prevent some candidates from being elected. Even with no explicit electoral threshold, the natural electoral threshold is determined by the district magnitude, the number of members elected in each district. Decreasing district magnitude is one of the ways to reduce political fragmentation in the chamber. However, it causes some wasted votes and produces more disproportionality. Under proportional representation, the more members being elected in the contest, the more fair the result.On occasion, lost votes in proportional representation have resulted in a party winning an outright majority of seats without winning an outright majority of votes. For instance, in the 2002 Turkish general election, the AKP won more than two-thirds of the seats in the Turkish Parliament with just 34.28 percent of the vote due to a large electoral threshold of 10%. In the 2013 Bavarian federal state election in Germany, the CSU party won less than a majority of votes but won a majority of seats.
Ranked voting
, unlike traditional plurality systems and list PR systems, allow voters to redirect what would otherwise be a wasted vote to other candidates. The goal of ranked voting is to reduce the waste that occurs in many elections due to votes being cast for unsuccessful candidates or by the existence of winners' excessive leads over their nearest contenders. Additionally, the low number of wasted votes in conjunction with quota, used to measure the potentially wasted votes, ensures that most elected members are elected with the same number of votes, thereby producing fairness.In instant-runoff voting, a single-winner election system, the quota is a majority of votes cast, or at least a majority of votes still in play when the seats are filled. The votes cast for the last-surviving losing candidate and those cast for the winning candidate if that candidate received votes in excess of what they needed to win are wasted. But at most, this will be less than half the votes cast, which is considerably fewer than some first-past-the-post elections where two-thirds or more of the votes may not be used to elect the winner.
When not all candidates are ranked by every voter, ranked vote systems can produce exhausted ballots – ballots with votes that could have been redirected to lower preferences if the voter had ranked all candidates. These can be considered part of the wasted vote.
Under the single transferable voting, a multi-winner election system, the quota is something smaller than half of the votes. But because multiple members are elected, a large majority of votes cast are used to elect the winners. Thus, wasted votes are less common compared to single-winner ranked voting. Under STV, the number of votes not used to elect someone is commonly the same or close to one quota, so about 16 percent in a five-seat district, for example. Usually STV systems use the Droop quota.
A vote can also be thought of as at least partially wasted when a vote has been given to a candidate who is a lower preference for the voter than a higher-ranked candidate. For instance, the Australian Electoral Commission tells voters that "there is no such thing as a wasted vote" due to preferential voting preventing candidates from finishing in third place or lower in cases where the last runoff was between only two candidates. However, some votes may be considered partially wasted votes if they were transferred and then used to elect a lower-ranked preference. Excess votes and votes not being used to elect a winner occur often under first-past-the-post.
Measuring the effect of wasted votes
Measuring wasted votes is done by examining the difference between how votes are cast and how seats are allocated. Nation-wide, it can be done by examining parties' vote shares. It may also take place at the level of electoral districts, which act as sub-units of the whole. Sometimes, it is done where party lists are not used and may be done whether only a single member or several members are elected in a district.One measure of proportionality of representation is the Gallagher index. This measures the gap for each party between what was their share of votes and the share of seats it did receive.
Comparing wasted votes between parties in legislatures can also be measured by the efficiency gap. The efficiency gap is a frequently discussed method of measuring gerrymandering. A non-zero efficiency gap almost always indicates more wasted votes for one party and less for another, thus creating a disproportionate chamber of elected members. Where the first-past-the-post voting or other winner-take-all systems artificially create two types of voters, with the minority voters unrepresented in each, but in reverse ascendancy, the regionalized under-representation of the respective parties in each region may balance out, and the large number of wasted votes may be hidden in a system where the measure of the waste of a party's votes is offset in a relative manner. Such a situation may be the case when the large number of wasted Republican votes in New York are offset by the large number of wasted Democratic votes in Texas, or in Alberta, Canada, where urban provincial seats in the 2020s are held disproportionately by the social democratic NDP, while almost all rural seats are held disproportionately by the right-wing United Conservative Party. Such regionalized party-specific under-representation leads to polarized regional political and social behaviour, such as strategic voting.
Regionalized election patterns, where one party has repeatedly taken the same seat, lead to the artificial importance of swing seats and swing jurisdictions. Efficient election campaigns focus on swing seats because votes gained in swing seats are more likely to result in increased representation.
Example calculations
Example 1
Consider an election where candidates A, B and C receive 6000, 3100 and 701 votes respectively.If this election is conducted to fill a single seat by a plurality or majority, Candidate A is elected because they received a majority of the vote. The wasted votes are:
- All 3801 votes for candidates B and C, since these "lost votes" did not elect any candidate
- In the wider definition, the 2899 excess votes for candidate A are wasted, since A would still have won with only 3101 votes. Therefore, 6700 out of 9801 votes are wasted.
- The 701 votes for party C, which won no seats.
- In the wide definition, also wasted are:
- * 399 votes for A, since A would still have won eight seats with only 5601 votes against 3100 and 701
- * 299 votes for B, since with only 2800 votes, B would lose the last seat to C