Instant-runoff Vote

Instant-runoff Vote (IRV), also referred to as Ranked-Choice Vote (RCV), and Alternative Vote (AV), is a plurality voting system where voters rank their choices within a single election among multiple options for a single winner.^{(ACE, Bristow-Johnson, 2010) (MIT Election Lab, 2023)}

If a single candidate has the majority of the votes, the election stops and the candidate wins the election. However, if no candidate has a majority of the votes, regardless of the plurality, then the last place candidate is removed and all their votes go to the next candidate the individual voters ranked in the list.^{(ACE, Bristow-Johnson, 2010) (MIT Election Lab, 2023)}

For example, if there are five candidates and no candidate has a majority, everyone who voted for the last place candidate as their first choice would have all their votes transferred to the second choice they put on their ballots.

Here’s a visualization of how counting votes within this system may work:

^{(MIT Election Lab, 2023)}