Single non-transferable vote

Voting

Each voter selects one candidate.

Counting The Votes

The n candidates with the most votes win, where n is the number of candidates to be elected.

An example

2 seats to be filled, four candidates: Andrea, Brad, Carter, and Delilah.

• 5 voters choose Andrea
• 17 voters choose Brad
• 8 voters choose Carter
• 13 voters choose Delilah

Brad and Delilah are the winners.

Proportional Representation

SNTV results in crudely proportional elections when the parties have accurate information about their support. If there are n candidates to be elected, Andrea can guarantee being elected by receiving 1/(n+1) of the votes, because n other candidates can't all receive more than her. However, it can become very difficult for parties to receive representation proportional to their strength, because they are forced to judge their strength prior to deciding how many candidates to field. If they field too many, they might dilute each others' vote and all lose. If they field too few, they might not win seats proportional to their true level of support.

SNTV also allows small protest parties to gain legislative seats. By fielding a small number of popular candidates, a small party can meet the threshold for election.

Potential for Tactical Voting

The potential for tactical voting is large. Receiving only one vote, the rational voter must only vote for a candidate that has a chance of winning, but will not win by too great a margin. This also creates a gigantic opportunity for tactical nominations, with parties nominating candidates similar to their opponents' candidates in order to split the vote.

SNTV also results in complicated intra-party dynamics because in a SNTV system, a candidate must not only run against candidates from the other party, he or she must also run against candidates from their own party.

Because running on issues may led to a situation in which a candidate becomes too popular and therefore steals votes away from other allied candidates, it has been argued that SNTV encourages legislators to join factions which consist of patron-client relationships in which a powerful legislator can apportion votes to his or her supporters. It has been argued that many of the characteristics of the Kuomintang in Taiwan and the Liberal Democratic Party of Japan arise for this.

In addition, parties must ensure that their supporters evenly distribute their votes among the party's candidates. In Taiwan, the Kuomintang does 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.

In Taiwan, the party structure is further complicated by the fact that while legislators are elected by SNTV, executive positions are elected by a First Past the Post. This has 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 promotes.

See also: Plurality voting, Single transferable vote