This is probably the most popular alternative to plurality elections. The name is accurate. Most people are familiar with runoff elections. They become necessary when the law requires a majority of votes for a winner, but there are a lot of problems with them. They are expensive. Voters do not like having to go to the polls twice and voter turnout tends to diminish for the runoff election.

IRV is a reform that allows voters to rank candidates in order of preference, so that in cases where there is no initial majority winner, a runoff recount can be conducted without a new election to determine which candidate is actually preferred by a majority of voters. Instead of casting one vote for one candidate, voters rank them all. If one of the candidates receives a majority, that person is the winner and nothing more is done, but if there is no majority winner, then the candidate with the least first-place votes is eliminated and the second choice votes from these ballots are then transferred to the other candidates. This process continues until someone emerges as a majority winner.

Proponents make a number of claims for this system:

  • It ensures that the winner has the approval of a majority, not just a plurality.
  • It allows more participation in the election for both independents and third parties, thus encouraging wider involvement and discussion of issues. Voters know that even if their favorite candidate comes in last, their second choice will matter. No more spoilers and no more wasting your vote.
  • It will decrease the incentive for negative campaigning. In a crowded field, candidates may need to get some 2nd and 3rd place votes, as well as 1st place votes in order to win. They'll be less likely to “go negative” if they need their opponent's voters, too.
  • IRV saves money. (This is true only where additional runoff elections would otherwise be required).

Opponents have two main objections:

  • The ballot becomes excessively complicated and confuses voters.
  • It makes the vote counting process too complex and thus subject to error and unnecessary expense.

They also maintain that IRV does not do what it claims, that it does not encourage third parties or produce a majority winner, and that it punishes rather than helps moderates. These arguments are rather complex and somewhat problematical. In truth, we probably need more actual experience with IRV to know how well it really works. You can find more in favor of IRV here and against it here.

There are many other voting systems. If you are interested in a short version of what voting theorists have to say about their pros and cons, you will find it here.