Firstly I agree with Antony’s recommendations 2-4 and especially endorse #4. Number the whole paper if you have any opinions or preferences for or against any candidates or parties who you would have left unnumbered. If you don’t, you’re being a dummy. There should be ads about it like there are about drink driving. Only stop if you get to a point where you are really completely indifferent about who among the remaining candidates gets in or misses out.
I agree with some of Antony’s attempts to make points against tactical voting but I disagree with others. It depends on what kind of tactical voting is suggested. The fact is that there are sound principles of tactical voting in Hare-Clark that are strongly mathematically justified and there are things that you do not need to be an expert on Hare-Clark to anticipate and thus protect your vote from being partly wasted while still in its preferential youth. However, this only remains the case while knowledge of the idea of tactical voting remains relatively scarce.
I suggest the following basic principle of sound tactical voting:
1. Do not vote 1 for any candidate who you think will or even may gain a quota on the first count. If such a candidate is indeed your preferred candidate, first vote 1 for a candidate who has no chance, and then vote 2 for your preferred candidate.
(I think that any forms of tactical voting other than the above are indeed very risky and it is easy to go astray. For instance, it may be (we don’t know) that Andrew Wilkie would have been elected had 100 Andrew Wilkie supporters realised that to put their man in a successful contest with Richard Lowrie rather than Elise Archer for the final seat, they should in fact be voting not 1 Wilkie, but 1 Lowrie. Some of these things are inscrutable in advance even to experts.)
In defence of my own suggestion concerning the effectiveness of my own form of tactical voting by (at least reasonably) intelligent and aware voters, I will make the following points:
It is a potential waste of part of your vote to vote 1 for a candidate who either will, or is very likely to, get a quota on the first count. The reason is that that candidate does not need your vote to get elected; they will win anyway. If they get a quota on the first count then part of your vote, possibly most of it, will be used up contributing to electing them, whereas had you voted 1 Nohoper 2 Electoral Megastar, your vote would be in the count at full value.
It’s true that voting 1 for Electoral Megastar, while resulting in the loss of part of the value of your vote, slightly increases the passed-on value of all Electoral Megastar’s other votes, so a whole vote of preferences is still passed on by the EM as a result of you voting 1 for them, and perhaps those preferences will be similar to yours, so your vote won’t be much impurified. But if your views on preferencing differ from those of the bulk of EM’s supporters, this means that part of the value of your vote is effectively topped up with preferences heading in different directions.
The worst case is voting 1 for Electoral Megastar 2 Lineball Contender, where Electoral Megastar gets, say, 1.01 quotas, and most of EM’s voters do not like Lineball Contender and have actually preferenced one of his/her rivals. In this instance the net effect of you voting 1 Electoral Megastar is actually to injure the net chances of your second preference, Lineball Contender, by almost a whole vote. Had you instead voted 1 Lineball Contender 2 Electoral Megastar (even if you mildly preferred them the other way around) then you would have benefited LC by the full power of your vote, while EM gets in anyway without needing any help from you.
Now, it may be that you are not so sure Electoral Megastar will get in, and may be worried that Lineball Contender might pip them if you vote for LC first, but if you’re really really worried about that, you can just vote 1 Nohoper 2 Electoral Megastar 3 Lineball Contender. When Nohoper is excluded, EM gets your vote at full value if not elected on the first ballot; if they are elected on the first ballot it goes straight to LC at 100%.
To indicate a real case of this sort of thing, in Braddon a small number of voters voted 1 Rockliff 2 O’Halloran. Their vote assisted Rockliff to get elected, but he didn’t need it. As Rockliff was only slightly over quota the value passed on to O’Halloran was tiny, but by adding to the size of Rockliff’s surplus, their votes boosted the value of all other 1 Rockliff votes. The net impact of their vote (ignoring rounding, which makes it more like that much chance of having one vote’s impact) was to improve O’Halloran’s position by .04 of a vote but that of Brooks and Whiteley by about .32 each, and since Whiteley was O’Halloran’s real opponent (fizzer though that was) such votes in fact could have harmed O’Halloran’s chances by giving more advantage to Whiteley than O’Halloran, or at best been washed out of the system as a “loss to fraction”.
While it is extremely risky to try to juggle your ticket order based on picking winners and losers from midfield, you don’t need to be a Hare-Clark expert to realise that some candidates just will not get elected, while others are quite likely to bolt in. Obscure bottom-of-the-ticket Green candidates, ungrouped candidates with no media profile or ads, and Socialist Alliance candidates are all examples of people who just do not get elected.
At the other end just about any mug could tell that Will Hodgman would get a quota on the first count, and other candidates who any even vaguely informed voter looking at 2006 or past federal results could have picked as having some chance of a quota on #1s included McKim, O’Connor, Bartlett, M O’Byrne, Ferguson and Rockliff. Some of these did not get quotas on the first count but there was clearly some chance that they might.
Antony suggests it is risky to try to second-guess whether, for instance, Matthew Groom (who got elected easily but was just short of quota) would have got a quota. He says “If Groom had got over a quota your preference would count, if he got less than a quota it wouldn’t, but how is any voter able to assess that.” Quite true, but actually a 1 vote for Groom is a loser tactically in either case. If he gets a quota then only part of the vote is passed on and the voter’s intentions are diluted for the sake of voting for a candidate who won and did not need that vote. If he misses a quota on the first count anyway the vote just sits with him and isn’t distributed, again for the sake of a candidate who got elected anyway. A vote 1 Barnes (SA) 2 Groom (Lib) at least avoids the first problem and also amuses the scrutineers. Advanced Liberal players who were confident Groom would get in anyway would probably give their 2 (or more likely their 1) to Lowrie or Archer.
The Hare-Clark system is a mechanism for translating voter intention but while it is elegant in many ways it is not fault-free (and indeed no counting system can be) and can have perverse outcomes that fail to fairly represent the stated intention of the voter. Not all votes are equal and the Denison cutup featured at least two situations where a party may have benefited had one of its candidates been able to give votes to another candidate - in one case from the enemy party. The system is rife for tactical exploitation and does have tactical loopholes that can be used successfully by voters with only a limited level of political knowledge.
Note: the purpose of the above is not to argue that voters “should” vote tactically as a matter of any kind of para-moral advocacy. It is, rather, to demonstrate that (i) there are cases where voting tactically reliably protects the power of your vote (ii) there are cases where voting non-tactically can result in net harm to your desired electoral outcomes (iii) there is at least one principle of effective tactical voting that is not rocket science to implement.