One of the biggest stories of the recent Queensland state election was the huge shift in preference flows towards Labor, with a big drop in the exhaustion rate across the state.
Opinion polling was quite accurate in predicting primary votes, but the method of distributing preferences according to the real flow of preferences at the previous election significantly overstated the two-party-preferred vote for the Liberal National Party.
It shouldn’t have been as much of a surprise as it was – the largest proportion of minor party votes in Queensland in 2012 came from Katter’s Australian Party, who had since dropped in the polls and were only running in a small number of seats.
There are two major jurisdictions in Australia that use optional preferential voting in single-member electorates, and the other one will be voting in just over a month, in New South Wales.
Like in Queensland, the last New South Wales election saw a big drop in the Labor vote and a majority of Labor’s seats being lost to the Coalition. We also saw a big decline in the number of seats where the Greens opted to preference Labor (as opposed to issuing a ‘just vote 1’ how-to-vote).
So I was curious whether there had been a significant drop in preference flows to Labor in 2011, that could possibly revert to form in 2015.
The following table shows the proportion of minor party preferences flowing to Labor, the Coalition or exhausting.
|Election||ALP preferences||LNP preferences||Exhausted|
Unlike Queensland, there was only a minor shift in preferences – LNP preferences increased by just over 2%, and Labor preferences dropped by just under 3%, with the remainder resulting in an increase in exhausted preferences.
This isn’t surprising, considering that there was no party playing a similar role to KAP in the 2011 election.
The above table brings together all preferences for all minor parties, but there is some analysis giving indications of how preferences flow for each minor party.
Antony Green produced a report for the NSW Parliamentary Library after the 2007 election which re-examined ballot papers for minor parties to precisely identify how each minor party’s primary votes flowed as preferences. The normal distribution of preferences doesn’t allow for this process, as votes can flow from one minor party to another. This process of post-election study is conducted after every federal election by the AEC, but is not regularly performed for state elections. It doesn’t appear that a similar study was conducted in 2011.
In the 2007 study (on page 59 of the PDF at the above link), Green breaks down preference flows based on each party, and how they preferenced in that seat. In the 73 seats studied, the Greens preferenced Labor in 43 seats and exhausted in the remaining thirty. There was a significant difference in preference flows in these two groups of seats – 46.2% of Greens votes flowed to Labor in seats where the Greens directed preferences, and only 33.2% flowed to Labor where they didn’t.
In 2011, the Greens only preferenced Labor in five out of 93 seats. Presumably that number will increase in 2015, but the previous evidence suggests that the decline in Greens preferences to Labor only produced a small shift in actual preference flows in 2011.