Instant-Runoff
How It Works
Instant-Runoff Voting (IRV), also known as Ranked-Choice Voting (RCV), asks voters to rank the candidates by preference. In the first round of counting, only the first-choice votes are considered. If one candidate receives more than 50% of the first-choice votes, they are declared the winner. However, if no candidate reaches this majority, the candidate with the fewest votes is eliminated, and their votes are redistributed to the remaining candidates based on the voters' next-ranked preference. This process continues, eliminating the lowest-ranked candidates one by one and redistributing their votes, until a candidate achieves a majority of the votes.
Best for: Medium to large groups (5+ people) where majority support is essential, and preferences between candidates are clear.
Trade-offs
- Majority support guaranteed: The winner is more likely to have broad support since the system eliminates the lowest-ranked candidates progressively.
- Reduces "wasted votes": Allows voters to support less popular candidates without fear of wasting their vote, as their vote is transferred if their first choice is eliminated.
- Discourages tactical voting: Since votes are transferred, voters are less likely to vote strategically for a less-preferred candidate just to block another candidate.
- Spoiler effect minimized: Helps avoid situations where a less popular candidate splits the vote, allowing a less-preferred candidate to win.
- Complex to understand and execute: The ranking and elimination process can confuse some voters, especially in casual settings.
- Time-consuming to count: Recalculating after each elimination makes the counting process longer and harder to manage manually.
- Can still lead to strategic voting: Voters can still manipulate rankings to influence which candidates get eliminated early. However, this is unlikely to happen in practice, especially with larger voter populations, because of the complexity of the system.
- Not proportional: If used in multi-winner elections, it can fail to reflect proportional support across groups or ideologies.