What is Instant Runoff Voting?
Instant Runoff Voting (IRV) is a simple voting method used
to select a single winner from a list of two or more candidates. By
collecting more meaningful information from voters, it gives them a
greater power of choice and measures their will more accurately. Invented
in the United States, this method has been used in Australia and Ireland
for many decades.
How does it work?
IRV allows voters to rank the candidates they find
acceptable. To determine the winner, voters' first choices are
counted. Votes for the last-place candidate are reallocated to the second
choices on their respective ballots, and this process is repeated until
someone has a majority.
Sample ballot
This is a ballot used to select a location for an
IRV activists' meeting.
IRV Meeting Location Poll
Instructions:
- Choose the meeting places you support in order of preference.
[_] | San Francisco |
[2] | Monterey |
[1] |
Los Angeles |
[3] |
Sacramento |
|
|
|
This voter prefers to meet in Los Angeles, could meet in
Monterey or Sacramento, and does not support a San Francisco
meeting.
| |
Here is a sample count:
Los Angeles |
|
Monterey |
|
Sacramento |
|
San Francisco |
|
San Francisco is ahead, but Monterey and Sacramento could be splitting
votes for LA.
Eliminated |
Redistributed Votes |
The colors correspond to the second choices of Sacramento
voters. Sacramento was fairly evenly split, but its voters leaned toward
northern California.
Los Angeles |
|
Monterey |
|
San Francisco |
|
Monterey still has enough votes to hand victory to LA.
Eliminated |
Redistributed Votes |
In fact, Monterey voters overwhelmingly favored San
Francisco as their second choice.
Los Angeles |
|
San Francisco |
|
All choices eliminated |
|
San Francisco wins.
|