Do South Australian voters get a Rau deal from the 'Voter Choice' Bill?

On 16 November this year, South Australian Attorney General John Rau introduced a bill into the House of Assembly (the lower house of South Australia's bicameral Parliament) to change the electoral system used to elect members of the Legislative Council. At present, members of the 22-member Legislative Council are elected eleven at a time for eight year terms; half face election at each election for the House of Assembly, the members of which serve four-year terms.

These elections use the single transferable vote system in one statewide district. However, the system has an important modification. Voters can either vote for one party ticket, which accepts an ordering of all the candidates in the election determined by that party and lodged with the Electoral Commission ahead of the election, or number every candidate in order of their preference. I have written about the severe flaws of this system in the past when used at the federal level, and many of the same criticisms apply to the South Australian system.

What the proposal means

If the bill is passed, South Australian voters will be faced with the same ballot paper (reproduced below) that they have received at past elections. However, the law changes substantially the functions of the above-the-line box.

South Australian Legislative Council sample ballot paper (Source: Government of South Australia 2011)

Under the current system, a vote like the one on the sample paper above would have been considered an adoption of the ranking of all the candidates that was submitted to the Electoral Commission before the election. Group C might have asked that an ATL vote for them next go to the candidates of Group A, then Group D, then B and E.

The new system changes the meaning of this vote. Now it only goes to the candidates of Group C. If all the candidates of Group C are excluded, the vote then exhausts. More importantly, voters may only cast one first preference above the line. So even if the voter voted 1 for Group C and 2 for Group A, the vote would only go to the candidates of Group C, and then exhaust. If a voter wishes to express preferences across party lines, they must vote below the line; the law creates a savings provision so that a first preference for the first candidate within a party group counts as an above-the-line vote for that party.

How would this work in practice? Well, the STV system initially allocates seats to candidates who receive a Droop quota ((votes/seats+1)+1). Once no candidate has a Droop quota, the candidate with the lowest number of votes is excluded, and their preferences. However, given that most South Australians vote above-the-line (96% at the last election), and that all above-the-line votes will immediately exhaust when their party does, this will mean that the exclusions will have a very minor impact, and it is most likely that the candidates which have the highest vote share after the process of allocating seats to candidates with Droop quotas will fill those final seats.

In effect, this means that the electoral system will be very much similar to the 'largest-remainder' method of party-list proportional representation. Each elected candidate within a party will receive exactly a quota of that party's vote before being elected, and the last candidate will receive the rest of that party's vote (the remainder).

How would it work?

It's worth noting that the largest-remainder system is designed to produce a generally proportional outcome, so the Legislative Council will likely continue to have a more proportional composition than the House of Assembly, which is elected in single-member districts using the single transferable vote. This means that the chamber can still fulfil its role as a check upon the powers of the Assembly; it may reject legislation, but cannot remove the government.

Nonetheless, the system will switch emphasis from attracting preferences to entirely attracting first preference votes. It would also cause a small change in the composition of the current Legislative Council, as can be seen below.

Party	Elected in 2010	Elected in 2014	Total	Change from GTV
Labor	4	4	8	0
Liberal	5	4	9	+1
Nick Xenophon Team	0	2	2	+1
Greens	1	1	2	0
Family First	1	0	1	-1
Dignity for Disability	0	0	0	-1

The Dignity for Disability Party won their seat in 2010 off preferences from other small parties, their first preference vote being only 1.2%. The new system would have given that seat to the Liberal Party. Family First won a seat off 4.3% of the primary vote and preferences from other parties; the new system would make that 0.52 quotas, to 1.55 for the Xenophon Team. It is possible that the new system could increase the number of below-the-line votes and make preferences a factor, hence giving that seat to Family First.

Michael Gallagher's 1992 paper on the subject of different methods of party-list proportional representation discusses effective thresholds for winning seats under these methods. He concludes that the threshold of exclusion; that is to say, the minimum number of votes a party can receive without securing a seat (adding one to this total will guarantee that party a seat) for the Droop quota and largest remainder system is 1/(s+1), where s is the number of seats to be allocated (this is in percentage terms). For South Australian elections, that would be equal to 8.33% of the vote. 

Distinct from this is the threshold of representation; that is to say, the smallest number of votes a party can receive and still receive a seat. For this particular figure, the equation is 2/(p(s+1)), where s is seats, and p is the number of competing parties. At the last election, this would be equal to 0.64% of the vote. A more general threshold equation, 75%/(s+1), gives a figure of 6.25%. 

Wasted votes

One advantage of the current STV system is that nearly all votes do go to an elected candidate. Given that a candidate must receive one quota to be elected, and the quota is (votes/(seats+1)+1), only enough candidates to fill all the seats may receive quotas; hence, the maximum number of votes that do not end up with an elected candidate cannot be more than votes/(seats+1) (8.33%).

The new system, however, would be more likely to disregard a larger number of votes. If we consider a vote that is not part of a quota or a remainder rewarded with a seat 'wasted', for my analysis of the last state election, 16.4% of all votes would be wasted, compared to the 8.3% of the vote left with candidates not elected in the actual election. These figures are relatively consistent for recent elections.

Nonetheless, it is worth noting that, to some extent, the current system lowers this figure to an unrealistic amount if voter preferences are to be legitimately consulted. If group voting tickets are to be done away with, getting this figure of only a quota wasted would require voters to cast a preference for every candidate or party group. This would lead to a high informal rate; when voters were required to preference every candidate for the federal Senate, informal rates larger than 10% were not uncommon. Usage of the federal Senate system, which has optional above-the-line preferences and potentially allows votes to exhaust, would increase this figure.

Labor's hypocrisy on exhausted votes

The South Australian Labor government's willingness to tolerate high exhaustion rates contrasts interestingly with Federal Labor's conduct during the debate over introducing optional preferential above-the-line voting. Labor opposed the changes, which passed nonetheless with support from the Greens and Nick Xenophon, on several grounds. One of them was the claim, made by South Australian Senator Penny Wong, that "It (the reform) will mean the votes of up to three million voters effectively going in the bin" and "disenfranchises more than three million voters—people who, at the last election, chose to vote for someone other than the major parties or the Greens". 

Ignoring, of course, what a load of nonsense these predictions were proven to be, I find it quite remarkable that the party that found it so undemocratic that above-the-line votes could exhaust is now introducing a system that guarantees above-the-line votes will exhaust.

 Why the state Labor government is not simply copying the federal system is somewhat confusing, and introducing preferences would improve on this proposal substantially. Nonetheless, the proposal does give voters certainty that their votes will count for their explicit choices only, and the value of preferences under GTV are very much questionable if preferences do not flow the way a voter wishes.

As always, Kevin Bonham has an excellent take on the matter, if you wish to read further.