STV Elections
Single Transferable Vote (STV) is a proportional representation voting method for electing multiple winners from a field of candidates. It ensures that elected candidates proportionally represent the diversity of views among voters.
STV is widely used by organizations like DSA, YDSA, cooperatives, unions, and local governments (Scotland, Ireland, Australia) to run fair multi-winner elections.
When to use STV
Use an STV Election when you need to:
- Elect a committee, board, or slate of delegates from a pool of nominees
- Ensure proportional representation — minority factions can win seats proportional to their support
- Run elections where voters rank candidates by preference
STV is not the same as Loomio's "Ranked Choice" poll, which is a simpler score-based ranking for choosing a single best option. STV handles multi-winner elections with vote transfers and elimination rounds.
Creating an STV Election
- Start a new poll and select STV Election as the poll type
- Add candidates as poll options
- Configure the STV settings:
Number of seats
How many winners should be elected. Must be less than the number of candidates.
Counting method
| Method | Description |
|---|---|
| Scottish STV (recommended) | The Weighted Inclusive Gregory Method (WIGM) used in Scottish local elections since 2007. Well-defined, straightforward rules. Best for most organizations. |
| Meek STV | A more mathematically precise iterative method. When a candidate is eliminated, votes are recounted as if that candidate was never in the race. Required by YDSA for officer and delegate elections. |
Quota type
The quota is the number of votes a candidate needs to win a seat.
| Quota | Formula | When to use |
|---|---|---|
| Droop (recommended) | floor(votes / (seats + 1)) + 1 | Standard for most STV elections. Guarantees a majority coalition wins a majority of seats. Used by Ireland, Australia, Scotland. |
| Hare | votes / seats | Higher threshold, more proportional for smaller factions. Preferred by DSA chapters to protect minority representation. |
Example: With 100 voters and 4 seats, the Droop quota is 21 and the Hare quota is 25.
How voting works
Voters drag and drop candidates to rank them in order of preference:
- Rank 1 = most preferred candidate
- Rank 2 = second choice
- Continue ranking as many candidates as desired
Voters are not required to rank every candidate. Unranked candidates will not receive any of that voter's support.
How the count works
- A quota is calculated (minimum votes needed to win a seat)
- First preferences are counted for each candidate
- If a candidate meets the quota, they are elected:
- Their surplus votes (above the quota) are transferred to voters' next preferences at a fractional value
- If no candidate meets the quota, the candidate with the fewest votes is eliminated:
- Their votes transfer to voters' next preferences at full value
- This process repeats until all seats are filled
Exhausted ballots
If a voter has ranked no remaining candidates, their ballot is "exhausted" and that vote is lost. This is why ranking more candidates is generally better.
Understanding results
After the poll closes, results are displayed showing:
- Elected candidates highlighted with a green chip
- Round-by-round table showing each candidate's vote tally at each stage
- Green highlight = elected in this round
- Red/strikethrough = eliminated in this round
- Faded = already elected or eliminated in a prior round
- Method and quota information showing which counting method and quota were used
Common configurations
| Organization type | Recommended setup |
|---|---|
| Most organizations | Scottish STV + Droop quota |
| DSA chapters | Scottish STV + Hare quota |
| YDSA elections | Meek STV + Hare quota |
| Government-style | Scottish STV + Droop quota |