What are Single Transferable Vote Elections?

Single Transferable Vote (STV) Explained

We don't yet know the specifics of how Your Party will conduct the CEC election, but this is generally how STV elections work.

STV is a proportional voting system used in multi-member constituencies.

  • Voters rank candidates in order of preference (1, 2, 3, etc).

  • To be elected, a candidate must reach a set number of votes called the quota.

  • First-preference votes are counted first.

  • Any candidate who reaches the quota is elected.

  • If a candidate has more votes than the quota, their surplus votes are transferred to voters’ next preferences (see below).

  • If no one reaches the quota, the candidate with the fewest votes is eliminated and their votes are transferred to next preferences.

  • This process repeats until all available seats are filled.

The key idea is that votes are rarely “wasted”, because they can move to another preferred candidate if the first choice cannot win or no longer needs them.

How First Past the Post (FPTP) works

FPTP is a winner-takes-all system used in single-member constituencies.

  • Voters select one candidate only.

  • The candidate with the most votes wins, even if they do not have a majority.

  • All other votes have no effect on the outcome.

The primary differences

  • Voter choice: STV allows ranking of candidates; FPTP allows only one choice.

  • Representation: STV produces more proportional results; FPTP often exaggerates majorities.

  • Wasted votes: STV minimises wasted votes; FPTP discards all losing votes.

  • Outcomes: STV encourages broader appeal and cooperation; FPTP favours large parties and tactical voting.

  • Constituencies: STV uses multi-member seats; FPTP uses single-member seats.

In short, STV aims to reflect voters’ preferences more accurately, while FPTP prioritises simplicity and decisive outcomes at the cost of proportionality.

How are excess votes fairly transferred to second preferences?

The principle

When a candidate reaches the quota, they have a surplus of votes. Those surplus votes are transferred to voters’ next preferences. This is meant to reflect all their voters fairly, not just whichever ballots happen to be picked up first.

So modern STV counts do not just take the “last pile of ballots” and move them one by one in sequence. That would absolutely make order matter and would be unjust.

Instead, systems use one of two main methods:

1. Fractional transfer (most rigorous method)

Used in places like Ireland.

All ballots for the elected candidate are transferred at a reduced value.

Example:

  • Candidate has 120 votes

  • Quota is 100

  • Surplus is 20

  • Transfer value = 20 ÷ 120 = 0.1667

Every ballot is transferred at 0.1667 of a vote to its next preference.

Result:

  • Order does not matter at all

  • Every voter is treated equally

  • This is deterministic and fair

2. Random sample of surplus ballots (older or simpler systems)

Some STV variants select a random subset of the candidate’s ballots equal to the surplus and transfer only those.

Result:

  • Order still does not matter

  • But randomness does

  • Two recounts could theoretically give slightly different outcomes

This is legal in some jurisdictions but widely seen as inferior to fractional transfer.

Video explanation

This video refers to Scottish Council elections, but the principle is the same.