How I’ll watch the 2022 Australian Federal election

With a few days to go until ballots begin to be counted in the 2022 Australian federal election, I thought I’d give an overview of some of the things I’ll be tracking on Saturday once counting starts. In addition to watching Antony Green on the ABC and keeping an eye on Kevin Bonham’s twitter feed and blog, I’ll be watching the AEC website and its booth-by-booth data. Here’s why…

My interest in analysing election results was born in the contest between Sophie Mirabella and Cathy McGowan in Indi in 2013. Cathy McGowan would have been described as a “teal” candidate in today’s terms, even though her campaign brand was orange. McGowan presented as an economically conservative yet socially progressive candidate in a similar way to today’s teal candidates.

Here are the things to keep an eye on:

  1. The overall margin that the sitting member had at the last election based on the two-candidate-preferred vote.
  2. First preferences, particularly swings on a booth-by-booth basis.
  3. Flows of preferences, leading to two-candidate preferred votes, and the swing of that.

The current Australian Treasurer’s seat of Kooyong is a good example. Let’s look at that seat, where Josh Frydenberg is facing a challenge from the teal candidate Monique Ryan.

The 2019 result

Frydenberg won that seat in 2019 with 55.7% of the vote on a two-candidate-preferred basis (2CP). He beat Julian Burnside, a Greens candidate who got 45.3% of the 2CP vote. Therefore, Frydenberg cannot afford to lose 6% of the 2CP vote if he is to retain the seat in 2022.

There are approximately 100,000 voters in Kooyong, so a 6% swing represents about 6000 votes.

In 2019, Frydenberg won 49.4% of first preferences, so he gained a little over 6% on top of his first preference votes once distributing preferences allocated by primary voters of other candidates. In contrast, Burnside won only 21.2% of first preferences, so he more than doubled his vote via the flow of preferences. Preferences matter.

It is interesting to see where the preferences came from. Frydenberg primarily got preferences from voters whose first preferences were Jana Stewart (ALP candidate; 2770 votes), Oliver Yates (an independent; 1793 votes), and Steven D’Elia (United Australia Party (936 votes). He got a little over 700 votes from three other candidates (two independents and an Animal Justice Party candidate).

You might be surprised that Frydenberg got so many preferences from ALP voters. The reason was the number of ALP voters. Jana Stewart won 16666 first-preference votes, and Frydenberg got 16.6% of these via preferences. So he got a relatively small proportion of relatively large number of votes.

Similarly, Oliver Yates netted a healthy number of first-preference votes (8890), but Frydenberg won only a small fraction of those (20.1%). Oliver Yates ran on a platform that very much reflects the current teal mood (a revolt against the direction of the Liberal Party, and demanding stronger climate action).

In contrast, preferences from primary voters for the UAP candidate flowed strongly to Frydenberg (79%).

If we add the first-preferences for the Greens, ALP, and Oliver Yates in 2019, then we have quite a strong block of potential votes for Monique Ryan in 2022 (47%). Clearly, Monique Ryan can’t be sure of winning all those first preference votes from 2019 (either as first preferences or on preferences ahead of Frydenberg). But given she has a chance of also taking some first-preference votes directly from Frydenberg, then Ryan seems clearly in the running.

First preferences in 2022

So I initially will be looking at Frydenberg’s first preference votes in 2022. The 2CP votes are what really matters, but first preference votes are normally reported before the 2CP counts. In 2019, Frydenberg’s first preference vote fell 8% but his 2CP fell by only 6%. But a drop in his first preference vote of around 6-8% in 2022 will worry him.

One key when looking at the swing in votes is to realise that the vote differs between booths. In particularly, pre-poll votes and postal votes have tended to favour Frydenberg in the past. The votes counted on Saturday evening will tend to be the votes from regular booths. So Frydenberg might suffer an apparent swing against him on Saturday evening, but some of that swing will likely be recovered in the following days as more pre-poll and postal votes are counted.

But any swing against him on regular votes will tend to be replicated across booths. You can see that in the 2019 result.

Swing to Frydenberg in the 2019 compared to 2016 for each booth versus the total votes per booth. The negative values are swings against Frydenberg. The only seat with a positive swing was a small “hospital” booth (a team that collects ballots from hospitals). You can see that the swings for the non-ordinary votes (orange circles, including pre-poll, absent and postal votes) were similar to the average overall swing. Once we have swings for 10-15 larger booths, we’ll have a good idea about where the seat is heading.

 So, I will be looking at the swings of individual booths. If those swings on first preferences average greater than 6%, then the result becomes interesting. I would guess if the average swing on first preferences is greater than 10% then Frydenberg will lose his seat, unless the UAP or some other right-leaning candidate is picking up a large fraction of those first-preference votes.

Preference flows

If the AEC starts publishing 2CP counts for individual booths along with the first preference counts, then it is possible to estimate the preference flows via linear regression. If those data become available, here is the approach I will use. The y-variable would be the number of 2CP that Frydenberg gains in each booth. The x-variables will be the first preference votes to each candidate. The regression coefficients will estimate the proportion of voters for each candidate who preference Frydenberg above Ryan. The coefficient for Frydenberg will be set to 1 (we know that his voters have all preferenced Frydenberg above Ryan). For the others, the coefficients will be restricted to between 0 and 1, and I will use the booth-by-booth data to estimate the coefficients (0 means none of those voters preferenced Frydenberg; 1 means they all preferenced Frydenberg). That will allow me to estimate the 2CP vote in booths that have reported first preference votes but not 2CP votes.

So there you have it. First, I will look at the swing needed to unseat the sitting member. I’ll monitor the swing of first preferences and then project how that swing will translate to the 2CP vote (either guessing based on previous years or a linear model based on booth data). That will allow me to predict the final 2CP vote for the whole electorate once the first preference votes become available. It would be possible to do a similar analysis for all the seats that are in play. This analysis relies on the AEC reporting booth-by-booth results on election night. Hopefully they will!

About Michael McCarthy

I conduct research on environmental decision making and quantitative ecology. My teaching is mainly at post-grad level at The University of Melbourne.
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