Electoral district


An electoral 'district, sometimes called a constituency, riding, or ward', is a geographical portion of a political unit, such as a country, state or province, city, or administrative region, created to provide the voters therein with representation in a legislature or other polity. That legislative body, the state's constitution, or a body established for that purpose determines each district's boundaries and whether each will be represented by a single member or multiple members. Generally, only voters who reside within the district are permitted to vote in an election held there. The district representative or representatives may be elected by single-winner first-past-the-post system, a multi-winner proportional representative system, or another voting method.
The district members may be selected by a direct election under wide adult enfranchisement, an indirect election, or direct election using another form of suffrage.

Terminology

The names for electoral districts vary across countries and, occasionally, for the office being elected. The term constituency is commonly used to refer to an electoral district, especially in British English, but it can also refer to the body of eligible voters or all the residents of the represented area or only those who voted for a certain candidate.
In American English, the term congressional district is used. The term "congressional district" is largely used in the United States and is distinctive from legislative districts. In the United States, congressional districts were inscribed into the Constitution to ensure representation based on population. Conversely, state legislation declares that "legislative representation be non-population related principles such as representation of counties, cities, or other geographical and political unit".
In Canadian English, the term electoral district is used officially, but they are colloquially known as a riding or constituency. In some parts of Canada, constituency is used for provincial districts and riding for federal districts. In colloquial Canadian French, they are called comtés, while circonscriptions comtés is the legal term.
In Australian and New Zealand English, electoral districts are called electorates, while the term electorate refers to the entire body of voters.
In India, electoral districts are referred to as "Nirvācan Kṣetra" in Hindi, which can be translated to English as "electoral area" though the official English translation for the term is "constituency". The term "Nirvācan Kṣetra" is used while referring to an electoral district in general irrespective of the legislature. When referring to a particular legislative constituency, it is simply referred to as "Kṣetra" along with the name of the legislature, in Hindi. Electoral districts for buli municipal or other local bodies are called "wards".
Local electoral districts are sometimes called wards, a term also used for administrative subdivisions of a municipality. However, in the Republic of Ireland, voting districts are called local electoral areas.

District magnitude

District magnitude refers to the number of seats assigned to each district, and in conjunction with number of districts, determines the number of district seats to be filled in an election. Staggered terms are sometimes used to reduce the number of seats up for election at any one time, when district magnitude is more than one.
The term District magnitude was first used by the American political scientist Douglas W. Rae in his 1967 dissertation The Political Consequences of Electoral Laws.
The district magnitude affects the ease or difficulty to be elected, as the effective threshold, or de facto threshold, decreases in proportion as the district magnitude increases, unless a non-proportional or pro-landslide election system is used such as general ticket voting.
The effect of varying district magnitude explains Duverger's observation that single-winner contests tend to produce two-party systems, and proportional representation methods tend to produce multi-party systems. where multi-member districts are used, threshold de facto stays high if seats are filled by general ticket or other pro-landslide party block system.
Duverger drew a correlation between proportional representation and multi-party systems. But many counter-examples exist, as PR methods combined with small-sized multi-member constituencies, of DM of less than 5 for example, sometimes produces a low number of effective parties. Malta, which uses DM-5 districts but where there are only two major parties, is an example of divergence from Duverger's rule.
Contests with district magnitude of 1 mostly use plurality voting in single-member districts but instant-runoff voting is used in other cases. In both systems each voter has one vote.
District magnitude is larger than 1 where multiple members are elected, and such districts have available a wide variety of election methods. Such districts usually use one of these systems: plurality block voting, list proportional representation, single transferable vote elections. Limited voting and single non-transferable vote is sometimes used but less often. In other cases, each seat in the multi-seat district is filled through a separate contest, usually through first past the post.
In list PR systems district magnitude may exceed 100, but in many cases the average district magnitude under list PR is only about 14.
In elections under single transferable vote systems, district magnitude normally ranges from 2 to 10 members in a district. Sometimes STV uses a greater district magnitude than that. Examples are at-large optional preferential elections in New South Wales Legislative Council and the 2025 Western Australian Legislative Council.
District magnitude is maximized where:
  • jurisdictions with a single electoral district for the whole elected body. This includes the legislatures of: the Netherlands, Serbia, Israel, Slovakia, and Moldova. In each of these cases, it takes less than a percentage point of the nation's electorate to capture a seat.
  • systems use a two-tier form of party-list proportional representation, using both local multi-member constituencies, and national levelling seats where parties' nationwide vote tallies have priority. That is the case in Scandinavia: Sweden, Denmark, Norway, and Iceland.
  • systems use a two-tier form of party-list proportional representation, using both local single-member districts, and national levelling seats, when the parties' nationwide vote tallies have priority. New Zealand uses such an MMP system.
  • systems use a three-tier form of party-list proportional representation, using both local single-member districts, and state and national levelling seats, to produce proportional rep in each state and nationwide based on party votes cast by voters. From 2017 to 2023, Germany's Bundestag also allocated additional members to make up for overhang seat won by parties and allowed parties to win single-member-district seats even if not proportionally due them. After 2023, a party is allowed to take only as many seats as its proportion of the second vote allows. If it elects too many single-member-district seats, they are disallowed, and allocated to another party.
DM is moderate where districts break up the electorate or where relatively few members overall are elected, even if the election is held at-large.
District magnitude may be set at an equal number of seats in each district. Examples include: all districts of the Northern Ireland Assembly elect 5 members ; all those of the Parliament of Malta elect 5 MPs. Chile, between 1989 and 2013, used a method called binomial voting, which assigned 2 MPs to each district.
In many cases, however, multi-member constituencies correspond to already existing jurisdictions, which creates differences in district magnitude from district to district:
  • Republic of Ireland for the Dáil Éireann: 3-, 4-, and 5-member districts.
  • Hong Kong for half of the Legislative Council of Hong Kong: 5- to 9-member districts.
  • The New Hampshire House of Representatives: 1- to 10-member districts.
  • South Africa 27 million registered voters and 400 seats
Proportional representation in a district elects multiple members who represent a variety of opinion, and therefore relatively few votes are wasted. Where the intent is to avoid the waste of votes, transferable ranked votes are used in addition to the election of multiple members. A quota, a set proportion of votes as a minimum, assures the election of a candidate and allows surplus votes to go to where they might be useful. In such elections, a large proportion of votes are used to elect someone.
The quota is often set as the inverse of the district magnitude plus one, plus one, the Droop quota. Droop is the mathematical minimum whereby no more can achieve quota than there are seats to be filled, if all the successful candidates were to receive quota.
In a STV contest, a candidate that accrues Droop quota is certain of being elected. STV is intended to avoid waste of votes as much as possible by the use of transferable votes. If the STV rules permit voters not to rank all the candidates or prevent them from ranking all the candidates, some votes are found to be exhausted, so votes are not transferred even if the candidate is elected or declared defeated or un-electable. Thus it is common for one or two members in a district to be elected without attaining Droop, but still they are seen to be the most-popular at that point in the count.
But where party list PR is used, the Hare quota is often used. For instance, in a system that uses party vote tallies to allocate seats, a party with ten percent of the vote will win a seat in a 10-member district as its 10 percent of the vote means it is due one seat of the ten. Thus, a threshold of ten percent in a ten-seat district is equivalent to a Hare quota. That same party will not win a seat in a 5-member district.
In systems where a noticeable number of votes are wasted, such as Single non-transferable voting or first past the post voting, or Instant-runoff voting, especially if voters are prohibited from ranking all candidates, candidates may win with less than Hare or even Droop.
Larger district magnitudes means larger districts, so reduces gerrymandering. Gerrymandering is the practice of partisan redistricting by means of creating imbalances in the make-up of the district map, made easier by a multitude of micro-small districts.
A larger district magnitude also means fewer wasted votes. As well, a fair voting system in the district contests also means that gerrymandering is ineffective because each party gets its fair share of seats however districts are drawn, at least theoretically.
Multiple-member contests sometimes use plurality block voting, which allows the single largest group to take all the district seats. Each voter having just one vote in a multi-member district, Single voting, a component of most party-list proportional representation methods as well as single non-transferable vote and single transferable vote, prevents such a landslide.