Wasted vote

In plurality systems, most votes are considered "wasted" as they do not contribute to the final outcome. This is because the wasted votes include both "lost votes" for all candidates not finishing first, as well as the "excess votes" for the winning candidate beyond what was needed to win.

Comparing wasted votes between parties in legislatures determines the efficiency gap measure, which quantifies the bias in allocating voter preferences due to the shape of electoral districts. A non-zero efficiency gap indicates disproportionally more wasted votes for one party. The efficiency gap may be the most discussed method of measuring gerrymandering.[2]

In proportional electoral systems, representatives are elected in rough proportion to voter preferences, resulting in fewer wasted votes than in plurality voting.[3]

The wasted vote includes the total number of voters not represented by any party sitting in the legislature (or unrepresented voters).[4][5][6] The wasted vote share is calculated as: ${\textstyle v_{wasted}=\sum _{i=1}^{n}v_{i}}$ where ${\displaystyle v_{i}}$ is the vote share of unrepresented party ${\displaystyle i}$ and ${\displaystyle n}$ 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. Wasted votes in proportional representation increase with a higher electoral threshold, which is one of the ways to reduce political fragmentation. Even with no explicit electoral threshold, the natural electoral threshold causes some wasted votes.

On occasion, lost votes in proportional representation result 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 party won more than two-thirds of the seats in the Turkish Parliament with just 34.28 percent of the vote due to a large election threshold of 10%. In the 2013 Bavarian federal state election in Germany, the CSU party failed to obtain a majority of votes but won an outright majority of seats.

Ranked voting, unlike traditional plurality 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. A majority of votes cast, or at least a majority of votes still in play when the seats are filled, are used to elect someone under ranked voting systems. However, in single-member ranked voting (also known as instant-runoff voting), a portion of votes will still become wasted votes by being cast for the losing candidates or by being cast for the winning candidate if that candidate received votes in excess of what they needed to win. But at most this will be less than half the votes in the counting, which is considerably fewer than some first-past-the-post elections where two-thirds or more of the votes can at times not be used to elect the winner.

When not all candidates are ranked by every voter, ranked vote systems can produce exhausted ballots – ballots that could have been redirected to lower preferences if the ballot had been fully ranked.[7] In multi-member ranked voting, wasted votes are less common compared to single-member ranked voting. The amount of votes not used to elect someone is commonly the same as a quota, where the Droop quota is used.

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.[8] For instance, the Australian Electoral Commission tells voters that "there is no such thing as a wasted vote" due to preferential voting preventing votes from finishing in third place or lower, in cases where the last runoff was between only two candidates. However, a large share of votes in Australian lower-house elections are excess votes for the winning candidate or partially wasted votes that were used to elect a lower-ranked preference. These instances of waste occur more often, however, under first-past-the-post.[9]

Cardinal voting or score voting methods can reduce wasted votes.[10]

In the 1993 Polish election, the wasted vote reached 34.4 percent. The use of electoral thresholds, set at 5% for party lists and 8% for coalitions, resulted in some parties not being eligible for representation.

In the Russian parliamentary elections in 1995, more than 45 percent of party votes were wasted, by resulting in no seats for the party, again due to use of 5 percent electoral threshold. Nineteen of the parties that did not exceed the electoral threshold did win district seats so did have some representation.

In the 2002 Turkish general election as many as 46.33 percent (14,545,438) of votes were cast for parties that went unrepresented in the parliament.[11] An unusually-large electoral threshold of 10 percent prevented all but two parties from taking seats.

In New Zealand, the wasted vote was only 1.5 percent in the 2005 general election, 4.62 percent in the 2017 election, and 7.71 percent in the 2020 election.

In the Ukrainian elections of March 2006, 22 percent of voters were effectively disenfranchised. In the 2007 Ukrainian parliamentary election held under the same system, fewer voters supported minor parties and the total percentage of disenfranchised voters fell to about 12 percent.

In Bulgaria, 24 percent of voters cast their ballots for parties that would not gain representation in the elections of 1991 and 2013. In Germany in 2013 15.7 percent or 6.9 million votes were unrepresented.[12]

In the 2015 Israeli legislative election, the wasted vote was 7.1 percent. The election is held with the country as a single district, which reduces the potential effective threshold to a minimum but an electoral threshold of 3.25 percent means that some minor parties did not get representation.[13]

In the 2015 Danish general election, where MMP was used, the wasted vote calculated by the formula above in Denmark proper was 0.92 percent. The wasted votes in Faroe Islands and Greenland, referred to above, made up a very small proportion of the total 3.5 million votes cast across the country.

In the Netherlands, the wasted vote was 1.55 percent in the 2017 general election and 1.99 percent in the 2021 election. The low percentage of waste in the Netherlands was caused by a low electoral threshold. The threshold is set at 0.67 percent, which is the same as the effective threshold produced by electing 150 seats in a single district covering the entire country.[14]

When districts are used under PR, waste of district votes may occur. During Danish general elections in 2015 and 2019, in the Faroe islands, where only two members were elected and 23,000 votes cast, the waste of votes reached 51.3 percent (11,000) in 2015 and 46.2 percent in 2019. In Greenland, where two were elected and 20,000 votes cast, in 2015 21.96 percent (4300 votes) and in 2019 34.2 percent of Greenland voters were not represented in the Parliament of Denmark.

In the 2018 Swedish general election, the wasted vote was 1.5 percent.

In the 2019 European Parliament election in France, 19.79 percent of voters were unrepresented.

The 2019 Swiss federal election had a wasted vote share of 1.3 percent, caused by natural electoral thresholds.

In the 2020 Slovak parliamentary election, 28.39 percent of all valid votes did not gain representation.[15][16] In the 2021 Czech legislative election, 19.76 percent of voters were not represented.[17] In the 2022 Slovenian parliamentary election, 24 percent of the vote went to parties that did not reach the electoral threshold. In the German federal state of Saarland 2022 election, the total wasted vote was 22.3 percent.[18][19]

In the 2022 Latvian parliamentary election, unrepresented voters reached 29 percent.