Single non-transferable vote

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Single non-transferable vote or SNTV is an electoral system used in multi-member districts. It is a generalization of first-past-the-post, applied to multi-member districts. Unlike block voting, where each voter casts multiple votes, under SNTV each voter casts just one vote. The combination of single voting and multi-member districts produces mixed representation and thus proportional representation or semi-proportional representation at the district level.

Voting[]

In any election, each voter casts one vote for one candidate in a multi-candidate race for multiple offices. Posts are filled by the candidates with the most votes. Thus, in a three-seat constituency, the three candidates receiving the largest numbers of votes would win office.

SNTV, like Single transferable vote, can be used with non-partisan ballots.^[1]

Example[]

Three seats are to be filled among five candidates: A, B, C, D and E fielded by 3 parties X, Y and Z.

Votes	Candidate	Party
819	A	X
1,804	B	Y
1,996	C	Z
1,999	D	Z
2,718	E	Y

C, D and E are the winning candidates. Thus, Party Z gets two seats and Party Y gets one seat.

But counting the votes by party gives these vote tallies:

Party	Votes	Percent	Seats
Y	4,522	48	1
Z	3,995	43	2
X	819	9	0

Party Y has more votes than Party Z, but receives fewer seats because of an inefficient spread of votes across the candidates. If either party had risked trying to win all three seats, causing more vote splitting among supporters of Parties Y and Z, then A of Party X might have won a seat but either party Y or Z might then have taken one fewer seat.

Proportional representation[]

SNTV facilitates minority representation, that is, it produces mixed representation of large and small parties where no party takes all the seats.^[2]

In fact, SNTV would elect the same people as are elected in STV contests where the vote transfers do not move an initially-lower-placing candidate over an initially-higher-placing one. It is common for STV vote transfers to elect the same as would be elected under SNTV. But not having transfers, SNTV sees more votes wasted than under STV due to the votes placed on un-electable candidate or in surpluses received by successful candidate over and above the quota used in STV elections and not being able to be transferred.^[3]

SNTV produces representation that is most proportional (proportional representation) when political parties have accurate information about their relative levels of electoral support, and nominate candidates in accordance with their respective levels of electoral support or when all parties suffer from poor information of that sort. Knowing the portion of the votes a party can take allows it to avoid vote waste due to lessening the chance of vote splitting and inefficient placement of party support.

But under SNTV even inefficient distribution of votes allows more balanced representation than would be elected under either single-member plurality or Block voting.

Given ${\displaystyle n}$ candidates to be elected, Candidate A can guarantee success by receiving one more than ${\displaystyle {\frac {1}{n+1}}}$ of the votes (the Droop quota), because ${\displaystyle n}$ other candidates cannot all receive more than Candidate A.

But as SNTV is a plurality system, it is possible to win with less than that quota. To determine the successful candidates, candidates' vote tallies are compared with the vote tallies of others.

Vote spitting due to poor information on voters behaviour may deny a popular party its due share of representation. (Single Transferable Voting does not suffer from this handicap as votes are transferable and many are transferred and used that are wasted under SNTV.) Parties organizing slates of multiple candidates may nominate many candidates and then learn on election night that the party was not as popular as they thought.

If every party does that, all suffer the same inefficiency and the final result is proportional. If one party is more prudent, it may do better than the others. Because votes cannot be transferred, there is more chance of vote watage than under STV.

But in elections that use SNTV, represenation is usually mixed. it is rare for one party to make a sweep of a city's seats, a thing common in First past the post elections. The number of wasted votes in an SNTV election is generally lower than in First past the post elections as well.^[4][5]

Under SNTV, parties often do not receive representation exactly proportional to their strength, because it is difficult to accurately judge their strength when deciding how many candidates to field (strategic nomination) and difficult to direct patysuppotes as whole to spread their votes efficiently. If they field too many, supporters' votes might be split across too many candidates. The party votes might spread their vote numbers to the point where all of a party's candidates lose to a less thinly spread opposing party.

If a party fields too few candidates, they might elect all their candidates but not win seats proportional to their level of support, and the winning candidates would have more support than necessary and thus wasting votes.

The risks of poor strategic nomination are not equal for parties of various strengths. A large party would have much more to lose from the split vote effect than to gain from avoiding the wasted vote effect, and so would likely decide to err on the side of fielding fewer candidates (but probably not less than their existing number of seats). A small party with little representation would be more risk-tolerant and err on the side of too many candidates, hoping to gain as many seats as possible, perhaps even winning more than its proportion of the electorate if they can edge out candidates from larger parties with just a few votes.

SNTV electoral systems, like STV and proportional electoral systems generally, typically produce more proportional electoral outcomes as the size of the electoral districts (number of seats in each constituency) increases.

Potential for tactical voting[]

The potential for tactical voting in a single non-transferable vote system is large. Casting only one vote, a rational voter wanting to maximize the number of seats captured by his party should vote for a candidate of the party that has a chance of winning, but one that will not win by too great a margin and thus take votes away from party colleagues. This creates opportunities for tactical nominations, with parties nominating candidates similar to their opponents' candidates in order to split the vote. Like all multiple-winner selections, parties find it advantageous to run a range of candidates in SNTV elections.

SNTV has been measured through the lens of such concepts as decision-theoretic analysis. Professor Gary W. Cox, an expert on SNTV, has studied this system's use in Japan.^[6] Cox has an explanation of real-world data finding the, "two systems [plurality and semi-proportional] are alike in their strategic voting equilibria."^[7] His research found that voters use the information offered in campaigns (polls, reporting, fundraising totals, endorsements, etc.), to rationally decide who the most viable candidates are and then vote for them.

SNTV can result in complicated intra-party dynamics because in a SNTV system, a candidate runs against candidates from their own party as well as against candidates from the other party. SNTV elections are not zero-sum contests. Just because one particular candidate is elected does not mean that another specific candidate will not be. They both can be elected.

Because running on issues may lead to a situation in which a candidate becomes too popular and therefore draws votes away from other allied candidates, SNTV may encourage legislators to join factions that consist of patron-client relationships in which a powerful legislator can apportion votes to his or her supporters.

In addition, parties will do best if their supporters evenly distribute their votes among the party's candidates. Historically, in Taiwan, the Kuomintang did this by sending members a letter telling them which candidate to vote for. With the Democratic Progressive Party, vote sharing is done informally, as members of a family or small group will coordinate their votes. The New Party had a surprisingly effective system by asking party supporters to vote for the candidate that corresponded to their birthdate. This led to a system of vote allocation which had been adopted by all parties for the 2004 ROC legislative elections.

Usage[]

SNTV is used for elections in Puerto Rico, Afghanistan,^[8] Kuwait, Indonesia, Japan, Taiwan, Thailand, Libya, Iraq, Hong Kong and Vanuatu.

Puerto Rico[]

In Puerto Rico, where SNTV is known as at-large representation ("representación por acumulación" in Spanish), political parties vary the ballot order of their candidates across electoral divisions, in order to ensure each candidate has a roughly equal chance of success. Since most voters choose the candidates placed at the top of their party lists on their ballots, at-large candidates from the same party usually obtain approximately equal vote totals.

The two major Puerto Rican political parties, the Popular Democratic Party and the New Progressive Party, usually nominate six candidates for each chamber, while the much smaller Puerto Rican Independence Party runs single-candidate slates for both the Senate and the House of Representatives. The overall distribution of legislative seats is largely determined by the results for the sixteen Senate and forty House district seats, elected by plurality voting.

Japan, South Korea and Taiwan[]

SNTV was once used to elect the legislatures of Japan, South Korea and the Republic of China (Taiwan), but its use has been discontinued for the most part. It is still used in Japan for some seats in the House of Councillors (Sangi-in), prefectural assemblies and municipal assemblies.

In Taiwan it used for the six aboriginal seats in the Legislative Yuan (national legislature), as well as local assemblies. The party structure there was complicated by the fact that while members of the Legislative Yuan were elected by SNTV, executive positions were (and still are) elected by a first past the post. This created a party system in which smaller factionalized parties, which SNTV promotes, have formed two large coalitions that resembles the two party system which first past the post rewards. Starting with the 2008 legislative elections, SNTV was discarded in favor of a mixed single member district (SMD) with proportional representation based on national party votes, similar to Japan.

Hong Kong[]

From 1997 to 2016, the electoral system for up to half of the seats of the Legislative Council of the territory was nominally a party-list proportional representation system with Hare quota. In practice, political parties fielded multiple lists in the same constituency. For example, the Democratic Party fielded three separate lists in the eight-seat New Territories West constituency in the 2008 election, aiming to win three seats (they won two). Split list or split tickets is done in order to win more seats with fewer votes, since the first candidate on each list would require less than the Hare quota to get a seat. Supporters are asked to split their votes among the lists of the same party, usually along geographical location of residence. In the 2012 and 2016 elections, no candidate list won more than one seat in any of the six PR constituencies which returned a total of 40 seats, rendering the result effectively the same as SNTV.

In the 2021 Hong Kong electoral reform, the Standing Committee of the National People's Congress instituted SNTV in its amendment to Annex 2 of the Basic Law on 30 March 2021.^[9] 20 seats of the Legislative Council are returned by geographical constituencies (GC) through single non-transferable vote with a district magnitude of 2.

Libya[]

In accordance with its post-Gadaffi electoral law, Libya in 2012 elected 80 members of its 200-seat General National Congress using single non-transferable vote.^[10] Some commentators cited the system as a factor in the subsequent return to civil war in 2014.^[11]

Chile[]

After the 2015 electoral reform, Chileans elect their representatives to both houses of Congress through open lists presented by parties or party coalitions in each of the electoral districts into which the country is divided for the contest, allowing only one vote for one of the candidates inside any list. Once the voting is over, the distribution of seats in each district (which can range from 3 to 8 in the lower house and from 2 to 5 in the upper one) is carried out through the D'Hondt method, ordering the lists from highest to lowest according to the total vote of each one and the candidates within each one of them with the same principle.^[12]

Jordan[]

SNTV became the official electoral system for legislature elections in Jordan in 1993, the second election since the country's return to an elected parliament in 1989. The 1993 electoral reform introduced SNTV as the "one-man, one-vote", which was argued to be a more egalitarian alternative to the former "block vote" (or multiple non-transferable vote) where constituents can vote for as many candidates as there are seats in their constituency. The Jordanian opposition parties were heavily critical of the voting reform as it significantly hurt their electoral results. The Islamic Action Front was at the forefront of this criticism, boycotting 4 of the 6 elections held under this system. The last election held purely under this system was in 2010, whose parliament was dissolved after the Arab Spring protests in Jordan and a new election was held in 2013 using both SNTV and a national closed list with a proportional system. SNTV was completely abolished after the 2016 electoral reform where it was replaced with proportional open lists for each constituency.

Kuwait[]

Kuwait has used SNTV to elect the members of its National Assembly (Majles al-Umma) in five 10-member districts, starting with the 2012 election.^[13]

See also[]

• Single transferable vote
• Plurality-at-large voting (multiple non-transferable vote (MNTV))
• Runoff voting

References[]

External links[]

• A Handbook of Electoral System Design from International IDEA
• ACE Project—Expert site providing encyclopedia on Electoral Systems and Management, country by country data, a library of electoral materials, latest election news, the opportunity to submit questions to a network of electoral experts, and a forum to discuss all of the above
• Electoral Design Reference Materials from the ACE Project