Election System Reform
Instant Runoff Voting
by Steve Chessin

Instant Runoff Voting (IRV) combines the best features of two-round (runoff) systems and traditional plurality elections. It produces a majority result in a single election, just as if a runoff had been held, by allowing voters to indicate their second (and additional) choices in case their first choice fails to win.

In IRV, as in a traditional election, the voter is presented with a list of candidates.  However, instead of just indicating a single choice, the voter writes a "1" next to their first choice, a "2" next to their second choice (who they would want if their first choice could not win or was not running), etc., for as many choices as they desire.

To count the ballots, they are initially sorted by the first choices. If no candidate has a majority of first choices, the candidate with the fewest votes is declared defeated, and his/her ballots are transferred to their respective second-choice candidates and added to the vote totals of those candidates.  (If no second choice is indicated, that ballot is declared exhausted and set aside.)  This process is repeated until one candidate achieves a majority of the ballots cast, or (in the case of many exhausted ballots) only one candidate is left.  That candidate is the winner.

Note that a voter's first choice is not hurt by that voter also indicating a second choice, as the voter's ballot stays with his/her first choice until such time as the first choice is eliminated from the counting.  In fact, it is to the voter's advantage to rank as many candidates as s/he can, so that his/her vote will help to elect the candidate of his/her choice.

Instant Runoff Voting is used to elect the Australian House of Representatives and the President of Ireland, and by the National Organization for Women to elect their officers.

IRV is superior to a simple plurality system, as the winner has to receive a majority of the vote.  Unlike simple plurality systems, it is impossible for a fringe candidate to spoil the election for a mainstream candidate, as the voters who rank an erstwhile spoiler first will have their votes transferred to their presumably mainstream second choice.  IRV is also superior to a traditional runoff system, as there is no extra expense for the candidates (or the government) to hold a second election.

IRV also reduces the incentive for negative campaigning, as a candidate may need the second choices of supporters of one or more opponents in order to win.  Candidates risk alienating those voters if they attack their first choices.

The recent (October 1997) Ireland Presidential election provides a good real-life example of how Instant Runoff Voting works.  This is how the votes tallied:

1997 Irish Presidential Election

After the counting of first choices, Mary McAleese had the lead with 45.24% of the vote, but not a majority of the vote.  Since the totals of the lowest three candidates put together were less than that of the candidate in second place (that is, no matter how the votes transferred they would all be eliminated), to save time they were eliminated as a group and their votes transferred to the respective next remaining choice.  As it happened, more votes were transferred to McAleese than to Banotti, increasing her lead.

"Big deal", you might say.  "The person who had the highest vote total after the first count won anyway.  Why bother with second choices?"

Let's respond to that criticism by looking at the results of Ireland's previous presidential election in 1990.  There were three candidates in that race:

1990 Irish Presidential Election

After the counting of first choices, Brian Lenihan had the lead with 44.1% of the vote, and in a simple plurality election would have been declared the winner, even though he did not have a majority. But that's not how Instant Runoff Voting works. Since Austin Currie had the fewest votes, his ballots were redistributed by their respective second choices.  Most of them went to Mary Robinson, giving her a final count of 52.8% and making her the winner.

In a US-style election, Currie would either have spoiled the election for Robinson, or forced an expensive runoff. In Instant Runoff Voting, there's no such thing as a spoiler, and a second election is never necessary.  The application to US elections is obvious.