This is the first post in a topic I’m calling “Graph of the Day”. It will mainly be shorter posts where I’ll graph something I’ve been researching or otherwise think is worth documenting.
This post and its graphs are about the decline of three-cornered or triangular contests, that is districts where both Coalition parties nominate candidates against the Labor Party.
The decline has been steep, from more than 40% of districts in the mid-1980s to fewer than 8% at the last six Federal elections.
The number of three-cornered contests is likely to fall further if a proposal from within the Federal Coalition to introduce optional preferential voting comes to fruition.
My prediction of a further decline under optional preferential voting is based on the record of state elections in NSW and Queensland. NSW has used optional preferential voting for state elections since 1980, and it was also used for Queensland state elections from 1992 to 2015.
That the Coalition parties actively avoid three-cornered contests under OPV is clear. There has not been a three-cornered contest at a NSW election since 1999. In Queensland, after 61 three-cornered contests at the first OPV election in 1992, the numbers declined to one in 1995, two in 1998, and six at the 2001 election. There were no three-cornered contests in 2004 or 2006, and the Liberal and National Parties merged ahead of the 2009 Queensland election.Read More »The Decline of Three-Cornered Contests at Federal Elections