Preference flows under STV: An interesting case from Tasmania

Thanks to Kazuaro in the South Australia thread for this terrific tip:

Perhaps some people are also interested in the recent Hare-Clark STV election in Tasmania. Kevin Bonham has some interesting coverage on a seat that was closely contested between the Liberals and the Greens:

4 thoughts on “Preference flows under STV: An interesting case from Tasmania

  1. I am uncomfortable with the leak language Kevin uses, although I understand why he does. STV enables proportional representation of the electors, unlike rival systems which enable proportional representation of the parties. The two, as shown at the last senate election in Tasmania where the electors overrode the ticket order recommended by political parties, are not always the same.


  2. I don’t think the senate election is comparable to Kevin’s leaking. The senate election was basically a case of rigid lists: the voters were able to get together enough strength to bend the list order to their will. Lots of alternative systems could do that: Some with a great deal more success. The difference is mostly in who gets a seat once no parties have a full quota left on their own. In fact, does the senate electoral system really have any of the properties of STV? (e.g. representation of the electors vs parties)

    Kevin’s “leak” language seems perfectly reasonable from the perspective of the party. And when you’re discussing how the parties are represented, it’s a reasonable perspective to take. And when you’re discussion who’s in parliament, it’s reasonable to talk about party representation. Because once the electorate has voted, we’re irrelevant.


    • The senate system no lower uses rigid lists, although it did from 1983 to 2016. In Tasmania one Labor senator was elected contrary to the ticket order at the last senate election and a Liberal candidate came close to being elected in the same way. It follows that the contest is not restricted to the last seat.

      I would much prefer the Hare-Clark version of STV which applies in Tasmania and the ACT to the senate version, but questioning if the senate version is STV is simply not a tenable argument.

      Tasmania had always had the highest number of non-ticket voters, but under the 2016 reforms that number rose from 10.34% to 28.1%. There is a second way in which Hare-Clark electors can influence party behaviour in addition to altering the ticket order. At the 2018 Tasmanian state election, Premier Will Hodgman received 2.29 quotas in his district. That is going to confer a certain amount of authority in his arty that he would otherwise lack.


  3. You’re right. I think I misused the term “rigid list”. I suppose a rigid list would have to be one where it is legally possible for the electorate to change the order, but where that has never in practice happened. The new senate system obviously is not a case of rigid lists.

    I see this: with party list PR, we have OLPR with strong intra-list competition. The electorate clearly dominates in selected the successful candidates; the party is weak.

    We have closed lists with no intra-list competition. The electorate decides how many members will be elected, but the party selects their identity.

    We have in between systems. In these, a sufficiently aggrieved electorate might have some ability to influence who is elected (as well as how many per party), but by-and-large the party order prevails. I guess rigid lists are those in which it is empirically too hard, flexible lists are those where it is a reasonably common occurrence, and we could create infinitely many other adjectives to describe each possibility.

    With preferential-proportional systems, we can surely create an analogy. Hare-Clark STV is the equivalent of fully open list.

    We could imagine a system where one only has above the line party preferences as the equivalent of closed lists.

    And then we have in between systems. The new senate is obviously somewhat flexible.

    Regardless of whether someone wants to describe the flexible form as STV, I think we still need better clarity. You said “STV enables proportional representation of the electors, unlike rival systems which enable proportional representation of the parties”. STV is advocated because it eliminates safe seats and reduces party control.

    These seem true of Hare-Clark, less true of the new senate system (Eric Abetz was always getting in, regardless of what happened to Richard Colbeck), and untrue of the theoretical party-preferential form. The sentence seems like saying “PR is better than FPTP because an elector can vote for a candidate who lives and appeals mostly to those on the other side of the country”. It’s true, but only of OLPR. In CLPR, they can only vote for a party who nominates that candidate.


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