It’s no surprise that the informal rate increased at the recent Tasmanian state election, but I wanted to explore how high the rate went, and what might explain it.
Tasmania has a rule that voters must number as many boxes as there are seats to be filled. That was seven up until 1996, five from 1998 until 2021, and then seven again this year.
In part to match this rule, the three biggest parties each run seven candidates in each electorate, even though they would never have a chance of winning all seven. It means that a voter can number 1 to 7 just within their group and those preferences will stay with the group until that group has no candidates remaining in the count, and that they can be sure that their vote is formal.
(Running surplus candidates is also helpful for filling vacancies later in a parliamentary term, but it doesn’t explain why the Greens would run seven candidates rather than, say, three.)
But for smaller parties that don’t run the full magnitude of candidates, they need to ensure that voters preference outside the group. If someone were to just preference the three JLN candidates in a single electorate, their vote would have been informal. Thus the increased magnitude is a higher barrier for those minor party or independent voters. Someone who voted for Craig Garland needed to find four other candidates to preference in 2021, but six in 2024.
So, how much did things change in 2024?
For most of this analysis I’ve gone back to 1989, but I wanted to go back a bit further here to get more examples of elections with magnitudes of 7.
The 2024 election has produced the highest informal rate in at least fifty years. Indeed in the entire history of Hare-Clark, the only election producing a higher informal rate was 1946, when the informal rate spiked to 10.1%. I’m not sure why – if anyone knows what happened that year, please post in the comments. Apart from 1946, the informal rate has often cracked 5% but never 6%, until the 6.3% informal rate in 2024.
The magnitude is definitely a major factor in the informal rate. The four other highest informal rates in the last fifty years were all in the magnitude-7 era from 1982 until 1996. The informal rate never quite reached that level again in the magnitude-5 era, although it did climb through the last decade.
The informal rate was not consistent across the state, as the next chart shows.
The two southern electorates have traditionally had lower rates of informal voting, dating back to at least 2002, although the five electorates all had very similar rates in 1996 and 1998.
All five electorates went up in 2024, but the rates were much higher in the three northern electorates. The rates in Franklin and Clark returned to a similar level to the 1996 election, but the other electorates reached new highs not seen in the last thirty years.
So next I wanted to understand what other factors might play into the informal rate. We know that in single-member electorates under compulsory preferential voting the total size of the ballot paper is a factor. But it’s more complicated under Hare-Clark.
Should we look at the total number of candidates? That figure is highly influenced by the increase in magnitude. Labor, Liberal and the Greens ran six extra candidates between them in each electorate without necessarily increasing the difficulty in voting for anyone. I also looked at the total number of columns, or the number of columns running less than the magnitude of tickets.
But one thing I realised is that 2024 stood out on every metric. I would find somewhat strong correlations (up to about 0.5), but when I looked at it on a chart, it was clear that 2024 stood alone. When I separated the data into magnitude 5 and 7, any correlations disappeared. They particularly disappeared when I excluded 2024 entirely.
So this has led me to conclude that there is something particular about 2024 – it wasn’t just the return to magnitude-7 elections, although that did play a role. It may be that informal rate was higher because voters weren’t used to the higher requirement and will fall at the next election, or that the increased field of viable small parties and independents made it easier to screw up and number less than seven boxes.
Tasmania could partly deal with this problem by looking to the ACT. The ACT electoral system is very similar to Tasmania, although they still elect five members per electorate. The ballot papers do still advise voters to number five boxes. But in practice a ballot paper with a single clear 1 will still count.
Such an approach may result in a few more votes which end up being counted as formal and then end up exhausting more quickly, but I think it would still be an improvement. As long as parties and the Commission continue to advocate for voters to number at least seven preferences, it should allow more votes to count without lowering existing preference flows.