STV Basics: 18 flashcards

STV is a proportional representation system where voters rank candidates in multi-member districts, and votes are transferred based on preferences to elect multiple representatives.

STV uses multi-member districts and ranked voting with vote transfers to achieve proportional results, while FPTP uses single-member districts and plurality (most votes wins) without transfers.

A multi-member district is an electoral area that elects more than one representative to the legislature, unlike single-member districts used in FPTP.

The voter ranks candidates in order of preference (1, 2, 3, etc.) on the ballot paper.

Ranking allows votes to be transferred to the voter's next preferred candidate if their first choice is elected or eliminated, ensuring votes are not wasted and promoting proportional representation.

A quota is the minimum number of votes a candidate needs to be elected. The most common is the Droop quota, calculated as: (total valid votes / (seats + 1)) + 1.

Droop quota = (total valid votes / (seats + 1)) + 1 (rounded down to the nearest integer).

They are elected immediately, and their surplus votes (votes above the quota) are transferred to other candidates based on the next preferences on those ballots.

They are eliminated, and their votes are transferred to the next preferred candidates on those ballots.

A surplus is the number of votes a candidate receives above the quota needed for election.

To ensure that as many votes as possible contribute to electing a candidate, reflecting voters' preferences and achieving proportional representation.

It means the number of seats a party or group wins is roughly proportional to the number of votes they receive, leading to a more representative legislature.

After the first count, candidates who reach the quota are elected. Then, surplus votes of elected candidates are transferred. If no one reaches the quota, the lowest candidate is eliminated and their votes transferred. This continues until all seats are filled.

A vote that is transferred from a candidate who is either elected with surplus or eliminated to the next preferred candidate on the ballot, ensuring the vote is not wasted.

It minimizes wasted votes and produces proportional representation while allowing voters to choose between candidates of the same party, giving more choice and reducing strategic voting.

It can be complex for voters to understand and for officials to count, and it may lead to coalition governments or slower decision-making.

Those ballots are exhausted and are set aside; they do not count towards any other candidate.

STV is candidate-centered (voters rank individual candidates) and uses multi-member districts with transfers, while Party-List PR has voters vote for a party list and seats are allocated proportionally to party vote shares, often without transfers.