Pauline Hanson, Brian Burston, Malcolm Roberts

Tasmania’s federal Senate election went down to the wire. And when the dust settled, fewer than 150 ballots separated the Greens’ Nick McKim and One Nation’s Kate McCulloch.

McKim triumphed, at least in part because very near the final count, 1925 votes that had been going to the Shooters, Fishers and Farmers party exhausted. Under the old system, where parties or individuals assigned a preference to everyone on the ballot, it’s hard to see many Shooters’ voters having preferenced McKim over One Nation, or the Shooters’ party itself having favoured the Greens over One Nation when it came to preference allocation. It’s highly likely One Nation would have had another senator on the crossbenches.

The analysis comes from Monash University politics professor Nick Economou. “Clearly a very large number of far-right votes exhausted, and a Greens candidate succeeded,” he told Crikey. “It should concern us … With a margin so low, we have to wonder what would have happened if Shooters voters had been encouraged to cast more preferences.”

[Informal votes could have swung the election]

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Exhausted ballots were always going to be an issue with the new Senate voting system. At this year’s election, more than 1 million ballots stopped being counted, or were “exhausted”, before the final Senate counts.

This is a dramatic rise on the last election, and every election previous. In recent elections — where voters either numbered “1” above the line and had the parties pick their preferences or numbered  every single box below the line — the number of exhausted ballots never exceeded 7000 nationally. In 2013 and earlier, Senate ballots were exhausted only through numbering errors, rather than through voters intentionally choosing not to express full preferences — in most cases, parties expressed full preferences for them through the group voting tickets.

The new Senate voting system changed this by giving voters the option of numbering or expressing preferences for only a fraction of the total Senate candidates. In the 2016 election, this has led to a colossal increase in the number of exhausted ballots, from 6765 in 2013 to 1,040,865 — a figure 153 times higher. The fact that it was a double dissolution election may have exacerbated the figure.


Above and below: The number of exhausted votes by state in the past five Senate elections 


The number of exhausted votes is tracked by the Australian Electoral Commission at every stage of the Senate count. Almost half the exhausted votes nationally were in New South Wales, where 414,656 Senate ballots exhausted — just over 9% of formal (i.e. valid) votes. This is unusually high. Perhaps this was a function of the large number of candidates running, meaning people who numbered six (above the line) or 12 (below the line) preferences were leaving more boxes blank.

In Tasmania, there were 9531 exhausted votes — only 2.81% of all ballots. On the lower end of the scale, only 109 Senate votes in the Australian Capital Territory were exhausted. In the Northern Territory, not a single vote exhausted. In most cases, the high level of vote exhaustion had no impact on who was elected, but not always. Economou also points to Western Australia as somewhere where high levels of exhaustion in a close race advantaged some candidates (the National Party was excluded at the last count, and many of their votes exhausted — if they hadn’t, these votes would presumably have gone against the Greens’ Rachel Siewert).

[How your votes gets counted on election night]

Even a ballot that puts a major party candidate first or second can exhaust. Here’s how: say you’re a proud Tasmanian who really likes Eric Abetz and preference him first, below the line, on your Senate ballot paper. Now, let’s say Abetz is so popular with all the other proud Tasmanians that he actually exceeds his quota by 70%. That is to say, Abetz receives 1.7 times the number of first-preference votes he needs in order to get elected (not an unusual circumstance for someone high up on a major party ticket). What happens with that 70% surplus? Well, all the votes for Abetz get redistributed to their second preference, but not at the full value they were when they went to electing Abetz (the value is higher the higher the amount by which a candidate exceeded quota). This process continues for third-preference candidates — and fourth, fifth, sixth, seventh, 28th and on and on right up until a voter stops numbering preferences. However, such high numbers of exhausted ballots at the 2016 election meant that the AEC could not continue with this process with many ballots past a certain number of candidates. The number of voters expressing preferences on the election or otherwise of candidates lower down the election order is thus smaller.

The issue for democracy, if there is one, is that if a ballot exhausts, it is necessarily less pivotal to the final Senate chamber than one which was still being considered at the final count. Some ballots are thus more powerful than others. On the other hand, exhausted ballots are the result of someone choosing to express no preference past a certain point. And this can be seen as a democratic choice as well.

Tasmanian psephologist Kevin Bonham says Economou’s analysis of the Tasmanian result is probably correct. Still, he’s not as fazed about it. For one thing, the level of exhausted ballots was significantly below predictions (departing Labor Senator Stephen Conroy was claiming before the election that 3 million ballots would be exhausted — the actual figure was a third of this). And exhausted ballots, Bonham says, are the “least of the evils”.

“I think that the exhaust rate was quite low. The problem is that there is no perfect solution. If you don’t have some exhaust, then the alternatives are group ticket voting and people send their preferences to places they don’t know about, or you force voters to fully preference and punish voters for mistakes, leading to informal ballots. There’s no perfect solution.”

“Exhausted ballots are less of an evil than group voting tickets, and less of an evil than high informal rates.”