Proportional representation by means of single transferable votes

Proportional representation by means of single transferable votes:

The single transferable vote (STV) is a voting system designed to achieve proportional representation through ranked voting in multi-seat constituencies (voting districts).Under STV, an elector has a single vote that is initially allocated to his or her most preferred candidate, and as the count proceeds and candidates are either elected or eliminated, is transferred to other candidates according to the voter's stated preferences, in proportion to any surplus or discarded votes.

An STV election proceeds according to the following steps:

1. A candidate who has reached or exceeded the quota is declared elected.
2. If a candidate has more votes than the quota, surplus votes are transferred to other candidates. Votes that would have gone to the winner go to the next preference.
3. If no-one new meets the quota, the candidate with the fewest votes is eliminated and those votes are transferred.
4. This process repeats until either a winner is found for every seat or there are as many seats as remaining candidates.

In an STV election, a candidate requires a minimum number of votes – the quota (or threshold) – to be elected. A number of different quotas can be used; the most common is the Droop quota, given by the formula:

This can be understood with example:


If there are 20 voters & 3 candidate need to be elected. There are 5 candidates which are nominated for election: