The following description is copied from the BC Citizens’ Assembly: Fact Sheet #9 – Plurality Systems
Plurality Systems
The plurality system is currently used in British Columbia and throughout Canada. BC has used the plurality system in all provincial elections with the exception of 1952 and 1953, when the province experimented with a version of the Majority System called the Alternative Vote.
The contestants in a plurality system election are individuals – frequently aligned with a political party – who want to represent an electoral district. The winner is the most popular candidate, the one who receives more votes than any other. Unlike majority systems, there is no requirement that the winner get more than 50 per cent of the vote.
Plurality systems with single-member districts
- One candidate is elected in each district and voters each have one vote.
- Large parties tend to get more than their ‘share’ of the seats, while small parties tend to get less than their share of the seats unless their support is geographically concentrated.
- The winning party usually gets a majority of seats without a majority of all votes – a so-called “artificial majority”.
Plurality systems with single member districts are often compared to a race in which the winner is the one who crosses the finish line first. For this reason, the system is often called First-Past- the-Post (FPTP).
Plurality systems with multi-member districts
Plurality systems with multi-member districts have most of the same features as single-member plurality systems. There are several varieties of multi-member plurality systems:
Votes equal to seats or Block Vote
- Voters have the same number of votes as seats available in the district.
- Voters cannot give more than one vote to any one candidate
- Voters may divide support between parties, but generally tend to vote along party lines.
- Currently used in Vancouver to elect city councillors.
Votes equal to seats or cumulative vote.
Votes equal to seats or Cumulative Vote
- Voters have the same number of votes as seats available in the district.
- Voters are able to indicate a strong preference while still voting for several candidates, by casting more than one of their votes for the same candidate.
- Used in some US cities and states.
Votes less than seats or Limited Vote
- Voters have fewer votes than seats available in the district.
- Parties may run more than one candidate.
- Big party candidates tend to split the party vote among them
- Stimulates rivalry among candidates in same party and makes them very locally oriented.
- Possibility for small parties to win a seat if they strongly support one candidate – sometimes called Semi-Proportional .
- The share of votes required to win a seat – the quota – decreases as DM increases.
- Used in Spain to elect their Senate
Single non-transferable vote (SNTV)
- A variation of the Limited Vote.
- Gives voters just one vote in a district that elects several legislators
- Tends to works like a proportional system with regard to vote-seat shares but like a plurality system with regard to generating majority
- Used in Korea and Taiwan
District magnitude (DM):
District magnitude is the number of representatives elected from an electoral district. DM = 1 is now the most common for plurality systems and the easiest to use. As discussed, where the DM is greater than 1, the number of votes a voter casts may or may not equal the number of representatives to be elected. The DM can vary from electoral district to electoral district.
Ballot structure
Voters are presented with a list of candidate names and simply place a mark beside the candidate(s) of their choice. As indicated above, in multi-member electoral districts there are several variations of ballots, each producing different effects.
Formula
Votes are counted on a district-by-district basis for individual candidates, not parties. Independent candidates can have their name on the ballot on the same basis as party candidates. Winning candidates are those with the most votes; there is no minimum number of votes a candidate needs to be elected. Votes cast for the non-elected candidates do not contribute to electing anyone and so are sometimes called “wasted votes.”
The following description is copied from the Electoral Reform Society – UK
First Past the Post
First Past The Post, also known as Single Member Plurality, Simple Majority Voting or Plurality Voting
How does First Past The Post work? First Past the Post is the electoral system used to elect the UK parliament. Under First Past The Post voting takes place in constituencies that elect a single MP each. Voters put a cross on a ballot paper next to their favoured candidate and the candidate with the most votes in the constituency wins. All other votes count for nothing. We believe First Past The Post is the very worst system for electing a representative government.
Pros and cons of First Past The Post
The case for FPTP
It’s simple to understand and thus doesn’t cost much to administer.
It doesn’t take very long to count all the votes and work out who’s won, meaning results can be declared a handful of hours after polls close.
The voter can clearly express a view on which party they think should form the next government.
It tends to produce a two-party system which in turn tends to produce single-party governments, which don’t have to rely on support from other parties to pass legislation.
Parties have to appeal to the centre ground to win elections, so it encourages centrist policies.
The arguments against FPTP
Representatives can get elected on tiny amounts of public support as it does not matter by how much they win, only that they get more votes than other candidates. In South Belfast, the SDLP candidate in 2015 broke the UK record for lowest winning share of the vote, at just 24.5%.
It encourages tactical voting, as many voters vote not for the candidate they like the most, but against the candidate they most dislike.
The majority of votes have no impact, as votes cast in a constituency for losing candidates, or for the winning candidate above the level they need to win that seat, count for nothing.
First Past the Post severely restricts voter choice. Parties are coalitions of many different viewpoints. If you support a party, but not your local candidate, you don’t have a means of saying so at the ballot box.
Rather than allocating seats in line with actual support, First Past the Post rewards parties with support concentrated in geographical areas, i.e. with just enough votes to win in each particular area. Thus, losing 4,000 votes in one area can be a good idea if it means you pick up 400 votes in another. With smaller parties, this works in favour of those with centralised support.
With relatively small constituency sizes, the way boundaries are drawn can have important effects on the election result, which encourages attempts at gerrymandering.
Small constituencies also lead to a proliferation of safe seats, where the same party is all but guaranteed re-election at each election. This not only in effect disenfranchises a region’s voters, but it leads to these areas being ignored when it comes to framing policy.
If large areas of the country are electoral deserts for a particular party, not only is the area ignored by that party, but also ambitious politicians from the area have to move away from their homeland if they want to have influence within their party.
Because First Past the Post restricts a constituency’s choice of candidates, representation of minorities and women suffers from ‘most broadly acceptable candidate syndrome’, where the ‘safest’ looking candidate is the most likely to be offered a chance to stand for election
In a multi-party culture, third parties with significant support can be greatly disadvantaged.