NSW 2015 – where will the preferences flow?


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.

I blogged about the preference issue shortly after the election, and Antony Green posted about the final vote figures on Tuesday.

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.

ElectionALP preferencesLNP preferencesExhausted

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.

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  1. Labor was the incumbent government in all 3 of those NSW elections. I wonder if that is also a factor that might’ve created a generally stronger reservation amongst Greens voters to preference Labor based on presumed reservations about the government’s record, whereas they may be more inherently inclined to preference Labor when the Coalition is in government? I guess there’s not really any way to know that, even after this election, since we’ll presumably see, ala Queensland, much more widespread campaigns and messaging encouraging preferencing which should have a big impact.

  2. Off topic but I’m trying to make some maps of the 2014 SA election, in much the same way as you have done in the past but the ECSA website only says the suburb a polling booth was in, not its exact address. This info must have been widely available at the time but I’ve tried typing lots of different things into google, the Advertiser and ECSA websites but I can’t find those details now. Do you know where they are available? Thank you.

  3. @Sacha I think that’s where ‘third-party’ campaigns on preferencing come in. Parties and candidates have to make decisions about preferences based on many factors, not just the maths, not to mention that whenever they’re talking about preferences, they’re invariably shifting the focus off their own campaign and their own messages. Organisations like Getup or Lock the Gate can urge voters to preference without the same political concerns (internal or external) that each party or candidate has to balance in their own preference decisions.

  4. They say that in the federal political sphere, the ALP needs a 4 in front of their primary vote to win elections (off the back of Green Preferences). But that becomes a lot harder in State Politics because of the OPV.

    There is something further that needs to be considered as well: in Greater Sydney (with the exception of the Blue Mountains), The Greens Vote gets stronger the further east you go. In fact, the uneven spread of votes for the Greens in Western Sydney means that there are some seats where the CDP can even compete against them.

    What would be more interesting in this election would be looking at how important distributions will play by looking at seats where parties like the Greens or the CDP get a primary vote in Double Digits.

    There is a big difference between NSW and QLD in terms of the effects of preferences within the election and that is the relative strength of minor parties within Queensland (especially with KAP, PUP and ONP) alongside the Greens. This dilution of Primary Votes makes it more of a wild-card election for preferences. Here in NSW, this will be a lot closer to a FPP election with only the Greens (or a strong independent) being able to compete against the Coalition and the ALP.

    Looking forward to some of the seat profile.

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