Plurality block voting

Plurality block, also called as multiple non-transferable vote, and block plurality voting, is a type of block voting method for multi-winner elections. Each voter may cast as many votes as the number of seats to be filled. The candidates with the most votes are elected. The usual result when the candidates divide into parties is that the most-popular party in the district sees its full slate of candidates elected, even if the party does not have support of majority of the voters.
The term plurality at-large is in common usage in elections for representative members of a body who are elected or appointed to represent the whole membership of the body. Where the system is used in a territory divided into multi-member electoral districts, the system is commonly referred to as "block voting" or the "bloc vote". These systems are usually based on a single round of voting.
The party-list version of block voting is party block voting, also called the general ticket, which also elects members by plurality in multi-member districts. In such a system, each party puts forward a slate of candidates, a voter casts just one vote, and the party winning a plurality of votes sees its whole slate elected, winning all the seats; and is thus distinct from plurality block voting.

Casting and counting ballots

Block voting

In a block voting election, all candidates run against each other for m number of positions, where m is commonly called the district magnitude. Each voter selects up to m candidates on the ballot. Each of the voters have m votes, and are able to cast no more than one per candidate. They cannot vote for the same candidate more than once, as is permitted in cumulative voting.
Voters are permitted to cast their votes across candidates of different parties.
The m candidates with the most votes are declared elected and will fill the positions.
Due to multiple voting, when a party runs more than one candidate, it is impossible to know if the party had support of as many voters as the party tally of votes or if it had support of just the number of voters equivalent to the votes received by the most popular candidate and the other candidates of that party merely received votes from subset of that group.

Example

Candidates are running in a three-member district; each of the 10,000 voters may cast three votes. Voters may not cast more than one vote for a single candidate.
Party A has about 35% support among the electorate, Party B around 25% and the remaining voters primarily support independent candidates.
Candidates of Party A won in a landslide, even though they only received a plurality among the voters. This is because most parties run as many candidates as there are open seats and voters of a party usually do not split their ticket, but vote for all candidates of that party.
By contrast, a single transferable vote system would likely elect 1 candidate from party A, 1 candidate from party B and 1 independent candidate in this scenario.

Effects of block voting

The block voting system has a number of features which can make it unrepresentative of the voters' intentions. Block voting regularly produces complete landslide majorities for the group of candidates with the highest level of support. Additionally, like first past the post methods, if there are many parties running and voters do not engage in tactical voting, a small cohesive group of voters, making up only a minority of the voters, can elect all the open seats by merely constituting a plurality.

Landslide victories

Under block voting, a slate of clones of the top-place candidate may win every available seat. A voter does have the option to vote for candidates of different political parties if they wish, but if the largest group of voters have strong party loyalty, there is nothing the other voters or parties can do to prevent a landslide.
While many criticize block voting's tendency to create landslide victories, some cite it as a strength. Since the winners of a block voting election generally represent the same slate or group of voters, there is greater agreement among those elected, potentially leading to a reduction in political gridlock.

Tactical voting and strategic nomination

Block plurality voting, like single-winner plurality voting, is particularly vulnerable to tactical voting. Supporters of relatively unpopular third parties have a substantial incentive to avoid wasted votes by casting all of their votes for a slate of candidates from a major party.
Parties in block voting systems can also benefit from strategic nomination. Coalitions are actively hurt when they have more candidates than there are seats to fill, as vote-splitting will occur. Similarly, a coalition has a substantial incentive to nominate a full slate of candidates, as otherwise supporting voters may cast some of their remaining votes for opposing candidates.
Bullet voting is a strategy in which a voter only votes for a single candidate in an attempt to stop them being beaten by additional choices. Because the voter is essentially wasting a portion of their vote, bullet voting is only a good strategy when the voter has a strong preference for their favorite and is unsure of, and/or indifferent to, the other candidates' relative chances of winning, for example, if the voter supports an independent candidate or a minor party which has only nominated one candidate. Thus, block voting may look like single non-transferable voting.
This system sometimes fosters the creation of an electoral alliance between political parties or groups as opposed to a coalition. This has been the case in the National Assembly of Mauritius; the New Hampshire House of Representatives, with the election of multiple Free State Project as well as New Hampshire Liberty Alliance members; and in the Vermont Senate, with the elections of Vermont Progressive Party members Tim Ashe and Anthony Pollina. Historically, similar situations arose within the multi-member constituencies in the Parliament of the United Kingdom.

Compared to preferential block voting

Block voting, or block plurality voting, is often compared with preferential block voting as both systems tend to produce landslide victories for similar candidates. Instead of a series of checkboxes, preferential block voting uses a preferential ballot. A slate of clones of the top preferred candidate will win every seat under both systems, however in preferential block voting this is instead the instant-runoff winner.

Vacancies

In Brazil, where Senatorial elections alternate between FPTP and block voting, each main candidate is registered along with two substitutes. Votes in either election are cast and counted based on these three-candidate slates; when a Senator leaves office before their eight-year term ends, the first substitute takes their place, and then the second if needed.
On the other hand, in political systems with a culture of by-elections, filling vacancies under Block Voting can be harder than in other voting methods. This is because by-elections to fill a single seat in a multi-member district can be expensive. In the Philippine Senate that has staggered elections, the seat is filled up on the next scheduled election, such as in 1951, 1955 and 2001. In the first two elections, the seat for the vacancy is a separate ballot question, where the voters voted for eight senators, then a separate ninth senator from a separate candidate list. In 2001, it was in one ballot question, where voters voted for 13, instead of 12, senators, all from one candidate list.
There are alternative ways of selecting a replacement in such systems: one way is to fill any seat that becomes empty by appointing the most popular unsuccessful candidate in the last election, i.e. a countback. This was used in the City of Edmonton following the 1905 Edmonton municipal election.

Use of block voting

National elections

The Philippines is the country with the most extensive experience in plurality-at-large voting. Positions where there are multiple winners usually use plurality-at-large voting, the exception is the election for sectoral representatives in the House of Representatives. The members of the Senate and all local legislatures are elected via this method. The members of the Interim Batasang Pambansa were also elected under this method in 1978.
The following countries use block plurality voting in their national electoral systems:

Country

Legislative body

Latest election

Type of system

Seats per constituency

Electoral system

Total seats

Constituencies

Governmental system

Notes

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Sub-national elections

Other countries using block voting:

Canada, in many local government elections, and in Senate nominee elections in Alberta
China for the National People's Congress and local people's congresses in provincial, municipal and regional levels with combined approval voting
Ecuador in 1998
Hungary, for local elections in municipalities under 10,000 residents. The system is officially called "individualized list electoral system" or "electoral system using personalized lists", which can be loosely interpreted as meaning personalized block voting, as opposed to party list systems, such as party block voting or party list PR.
Iran, for the city and village councils
Lebanon
Philippines, for provincial boards, and city, municipal and village councils
Russia, in some local elections, e.g. in Moscow district councils electionsq
Syria
Tonga, for noble elections
United Kingdom, in some local elections in England and Wales.
United States, in some state and local elections.

In France, the election of municipal councilors takes place by majority vote plurinominal, in two rounds with panachage:

In the first round, candidates are elected if they receive an absolute majority of votes cast and the vote of a quorum of at least a quarter of registered voters;
In the second round, a simple majority suffices. If multiple candidates receive the same number of votes, the election is won by the older of the candidates when no one can be elected based on the number of seats

In British Columbia, Canada, all local governments are elected using bloc voting for city councils and for other multi-member bodies. In other Canadian provinces, smaller cities are generally elected under plurality-at-large, while larger cities are generally elected under the "ward system" which is a municipal adaptation of single member plurality. The sole exception is London, Ontario which has recently changed to the Alternative Vote. When Toronto was amalgamated in 1997, the new entity's first election used a similar rule. From 1871 to 1988, British Columbia had some multi-member ridings using plurality-at-large, and others elected under single member plurality, with the number of each varying from one election to the next. Other Canadian provincial legislatures have in the past used plurality-at-large or single transferable vote, but now all members of provincial legislatures are exclusively elected under single-member plurality.
In Hong Kong, block voting is used for a tiny proportion of the territory's population to elect the members of the Election Committee, which is responsible for selecting the territory's Chief Executive.