by Clay Shentrup

A major talking point from the Instant Runoff Voting community is that IRV "always elects a majority winner". We already know that this cannot be true in the absolute sense, because of Condorcet cycles. It is also false because IRV can improperly eliminate the true majority winner prior to the final round. But here we consider another reason why IRV, in practice, can easily elect a candidate without majority support: ballot exhaustion.

In San Francisco, we use a variant of IRV, ambiguously called "Ranked Choice Voting". With this system, voters pick a first, second, and third choice, instead of ranking all the candidates. What can then happen is that we have a final round in which the winner has less than 50% of the votes. Here is an example, from the official government web site for the City and County of San Francisco.

Notice that Ed Jew defeated Ron Dudum in the final round, with 8,388 votes (38.2%) to Dudum's 7,587 (34.5%). Jew won with far less than 50% of the voters supporting him. We did not see what more than 27% of the voters thought about the final Jew vs. Dudum match-up.

SOURCE

The same thing happened in District 6, where Chris Daly won with 45%.

SOURCE

The Moral?

In all cases where there was not an immediate first-round majority, the winner got less than a majority. Ranked Choice Voting is popular variant pushed by IRV advocates who often proclaim that IRV will always elect a candidate preferred by a majority of voters. Ballot exhaustion is yet another reason why, at least for the RCV form, those claims are false.