2018 Tasmania Postcount: Bass

Bass 3 Liberal, 1 Labor, 1 undecided
Re-Elected: Gutwein (Lib), Ferguson (Lib), Courtney (Lib), M O'Byrne (Labor)
Contest Between Parties: Dawkins (Green) vs Houston (ALP)
Houston has won

Warning: The Bass contest is mathematically complex.  This article is rated at Wonk Factor 4/5.

Welcome to the first of my post-counting threads from the Tasmanian state election, which will follow the post-count in the seat of Bass. These articles will be edited and updated as the counts progress.

Bass is the (doubtless expensive) jewel in the crown of the Liberals' blowout win tonight - they are currently running at a 1.7% swing to them in Bass, an amazing result.  With 85.7% counted, the Liberals have 3.53 quotas, Labor have 1.59, the Greens have 0.54 and the Jacqui Lambie Network have 0.28.  There's also 550 votes (0.05 quotas) for anti-Green independent Brett Lucas.  Labor's notional lead on primaries over the Greens is 455 votes.



In 2014 the Greens performed notably better on absent votes than the rest of the count, and the Liberals quite a bit worse.  However, absent voting is low in Bass, so I project this to advantage and disadvantage these parties by only about 0.01 of a quota.

Peter Gutwein has 1.41 quotas and Michael Ferguson has 1.26.  Michelle O'Byrne is sitting just over a quota and it is immaterial whether she makes it on primaries or perhaps on leakage from the Liberals.  The surpluses will probably put Sarah Courtney straight over the line (or if not, very nearly so) with some votes flowing directly or indirectly to the minor Liberals.  And then, all we have is elimination from the bottom up until someone crosses quota, or (perhaps more likely) someone is the only one left.

The Liberals will initially lose preferences to leakage and I estimate this loss (on current numbers) at about 0.04 of a quota. However from this point it is Labor who will start losing votes to leakage, as they have almost 4000 votes to distribute from other candidates to Houston (assuming she will stay in second), compared to around 1500 for the Greens.  High leakage has been seen in Bass when Labor candidates are cut out in the past (this was the seed of Kim Booth's famous win for the Greens in 2006).  The difference in leakage rates between the Greens and Labor is probably about enough to erase Labor's notional lead.  Indeed after factoring in leakage from all parties, but ignoring the Lucas and JLN votes, my estimates have Labor and the Greens about 400 votes up on the Liberals.

The problem for the Greens is the Lambie Network preferences - JLN voters at the Senate election very rarely preferenced the Greens, and are likely to include many of the same voters who voted PUP last time.  If this stays the case then the Greens are likely to drop about 300 preferences (if not more) compared to each major when the Lambie Network candidates are all excluded.  Brett Lucas won't help matters for them either.

A crunch point will arrive at which only Dawkins, Archer (or Wood) and Houston (or possibly Roe) are still in the count.  It seems there will be very little between the parties at this stage of the count, with Labor possibly a few hundred votes up on the others.  However, should Labor perform poorly on remaining post-counting, or encounter high leakage even by Bass standards, this may cease to be the case.

Assuming it is indeed that close:

* If the Liberals go out Labor should win
* If Dawkins goes out Labor will win easily
* If Labor goes out then I think Dawkins would win rather than the Liberals, but this might depend on the exhaust rate if the Liberals are further ahead than I expect.

The Liberals need three things to go right for them to win four: to be not last at this tipping point, to have Labor rather than Dawkins last, and for the Labor preferences to not assist Dawkins much.  Labor should win provided that they are not last.

Incumbents tend to be very good at sopping up preferences from here and there in tight contests.  However, Dawkins was not a full-term incumbent and did not have the profile of Kim Booth in his 2006 win.  Moreover she does not control whether the Liberals are behind Labor at the crunch point.  So on present numbers her position looks difficult, but it is too early to call the seat.

Update Wednesday: Rechecked figures including out of division (absent) and additional postals are up.  As expected the changes are minimal - the Liberals are still on 3.53 quotas , Labor on 1.58, the Greens on 0.55.  Labor's notional lead over the Greens has come down to 317 votes, which is just a touch smaller than I expected at this stage.  However, the Liberals' raw total hasn't come down at all.  (they are notionally 589 behind Labor and 272 behind the Greens).

Both these things are mildly good news for Dawkins because what she wants here is for Labor to go out at the tipping point - if this does not occur then it doesn't matter if she is ahead of the Liberals or not as she would almost certainly lose anyway.  However, she is still behind on my projection, because of the expected harmful impact of the Lambie preferences.  In the Senate election, Lambie preferences broke strongly to the ALP.  If they would break strongly to the Liberals in this instance that would be an immense help to Dawkins.

I have though seen some very limited scrutineering data that suggests a high (even by Bass standards) leak rate off some Labor candidates with Dawkins getting quite a bit of it, so I think this one is very interesting.  Labor need to do something about leakage in this seat - it's cost them twice before.

I've done some more modelling on the size of the Labor/Green gap at the tipping point and get it at about 250 votes in Labor's favour (using leakage rates from 2014 and assuming Lambie preferences break as per PUP preferences the same year).  I also find that in 2014 while the leak off Gutwein was only 7%, the leak off other Liberals was more like 10%.  On this basis even though Labor will have a higher leak rate (I am using 16% but it could be even higher) the fact that the Liberals are over twice as exposed to leakage counts against them being able to close their gap to Labor by any real amount (barring a remarkably strong flow of JLN and Lucas preferences).

So while it's close, I think Labor are the more likely winners.

Update Friday: The count in Bass has advanced from 91.12% to 91.58%.  The Greens made a very small amount of progress off the 310 added votes with the notional Labor-Green gap on primaries closing to 304 votes (down 13) and the notional Labor-Liberal gap closing to 582 (down seven).

Update Tuesday morning: Just another 157 primaries added for the final primary count.  The notional Labor-Green gap on primaries is 297  but the notional Liberal-Labor gap increased slightly to 601.  We now have three surpluses to throw: Gutwein, Ferguson, and O'Byrne (whose surplus will be worth only 93 votes).

Tuesday lunch: We have the three surpluses all done and the minor exclusions have started.  Because of exhaust the Liberals have dropped well behind Labor and now notionally trail Labor by 1126.  The notional Labor-Green gap is 308.  Labor's greater leakage exposure and greater tendency to leak should see the Liberals close that gap back by at least a few hundred but it would take a very strong flow off the Lucas and JLN preferences to close it by enough to put Labor out of business.  The minor exclusions are on now.  The Labor exclusions will be interesting.

1:45: Looks like the Greens ticket is also very leaky because of Dawkins' lower profile compared to Kim Booth.  On the first Greens exclusion the leak rate seems to have exceeded 20%.

2:30: Huge leakage off minor Greens continues with Labor now notionally 510 up on the Greens (though this should drop) and 1173 up on the Liberals.  While Labor are much more exposed to leakage than Dawkins from here, it's hard to see that the JLN preferences won't keep them ahead of her.  We still have to wait to see if Jennifer Houston will be Labor's final contender or if preferences might pool between the male candidates, though I think Houston should probably stay ahead as she has a 704 vote lead over Roe.  The remaining 2477 Labor preferences will be the major factor deciding that contest.

2:52: A key exclusion on now - anti-Green independent Brett Lucas.

3:55: Well that's interesting.  Lucas' preferences were indeed harmful to the Greens, but they weren't all that crash hot for the Liberals either.  The Jacqui Lambie Network gained 209, the Liberals 179, Labor 160, the Greens 88.  Notionally, Labor now leads the Liberals by 1143 and the Greens by 580 - but Labor has more votes to throw that can still leak, while the Greens are the least exposed to leakage.  A big pickup from Lucas was one of the Liberals' few remaining hopes to get into the final two.  I don't see the Liberals getting inside say 600 of Labor based on leakage and I can't see them gaining that much off JLN anyway, so assuming the Liberal preferences will favour Labor then it's getting hard to see how Labor loses.

5:53: Still plowing through the minor exclusions here.  Labor are currently notionally 796 ahead of the Greens, 1181 ahead of the Liberals.  There will be more leakage off the final minor Green candidate.  Maybe Labor will leak 1000 votes from their minor candidates (none of whom are excluded yet) but they're still likely to be ahead of the Greens at the key point, not that it matters as it doesn't look like the Liberals can catch either.

Wednesday

10:25: All the minor Greens candidates are excluded now and Labor leads the Liberals by 1236 and the Greens by 1143.  For Roe to stay in the race he now has 2708 Powell and Gore preferences to bridge a 778 vote gap to Houston.  Powell's preferences are likely to leak to Dawkins a fair bit but it will be interesting to see how much they do leak.  Remember the Liberals have more votes to leak here so even if Labor does manage to lose all their lead on leakage off their 4656 minor candidate votes they should still make the final two.

12:03: On Powell's exclusion there was a 225 vote leak (18.6%) of which 86 to Dawkins, 75 to the two Liberals, 40 to JLN and 24 to exhaust.  Gore came quite close to catching Roe but didn't do so and Houston is over 1000 up on Roe now so will be the final Labor candidate.  We now have the exclusion of Gore, probably followed by Roe.

12:48: Powell is gone and now Roe is excluded as well.  On Powell's votes there was about a 16% leak with the two Liberals taking 123, the Greens 86 and JLN 40 (I don't have the exact figure for exhaust).  Labor now notionally leads the Liberals by 503 and the Greens by 434.  On Roe's preferences Labor may fall to about the level of the other parties but there is still leakage from the Liberals to come and also the Lambie votes.  So still nothing here to say that Houston will not win. It is an open question whether the Liberals will gain enough over the Greens on JLN votes to make up for their own losses off leakage, so it could even be that Dawkins is out at the tipping point with her preferences to elect Houston.  It's also very close as to which Liberal candidate (Wood or Archer) goes out first, but I think Hoult will go before both of them.

2:40: Roe is done so Houston's on her own now.  After the usual massive Bass Labor leakage Houston is now 205 behind the Liberal total and the Liberals are 56 behind the Greens.  However we now have the Lambie Network votes (3077) which should push Houston past Dawkins, then the first Liberal exclusion. 

4:55: Hoult is out and the results are quite interesting.  The Liberals are now notionally in front by 379 over Houston who is 80 ahead of Dawkins.  The Liberals have a 223 vote surplus from Hoult (which could be more leaky than other votes as it is coming from a cross-party source) and then 3356 from (presumably) Wood to throw.  To stay in this Dawkins needs to gain 81 on Houston off Liberal leakage (seems unlikely, but she is an incumbent - and Simon Wood is a Launceston councillor as was Dawkins) and have the Liberals not drop 380 to Houston - bearing in mind that every Liberal vote that goes to Houston in the process counts as two (that seems unlikely too).  Then she'd need to win on Labor preferences (who knows?).  It looks like Houston is going to get over the three-way tipping point but it is still not certain. 

5:11 That Courtney surplus off Hoult was very leaky and the Liberal lead is cut to 269 over Houston who is 83 over Dawkins.  Assuming zero votes now went to Houston the Liberal leak would have to stay below 7.8% to keep Archer ahead of Houston, and at this stage of proceedings between the two most minor Liberal candidates that won't happen (especially as with Houston taking votes it is more like 6%).  So Houston gets over the tipping point.  If the Liberals are last (which I suspect they will be) then I might not call it at that point, because with an incumbent versus a non-incumbent you never know, but I would strongly expect Houston to win.  If Dawkins is last I will call it.

5:25: Final for night, so come back tomorrow to finish this one off.

9:10: Had a look at Liberal flows between Labor and the Greens in past elections when the Liberal ticket ran out of candidates:

2014 Bass - Green incumbent vs two ALP incumbents, split 81-19 of non-exhausting votes to Labor
2014 Lyons - Green incumbent vs ALP former MP, split 76-24 to Labor
2006 Bass - Green incumbent vs ALP non-incumbent, 70-30 to Labor
1998 Denison - Green incumbent vs ALP incumbent, 57-43 to Labor
1998 Franklin - Green incumbent vs two ALP incumbents, 56-44 to Labor
1996 Braddon - Green incumbent vs two ALP non-incumbents, 56-44 to Labor
1992 Braddon  - Green incumbent vs ALP incumbent, 71-29 to Labor

There's a fair amount of variation there but there is no precedent for the Greens getting more Liberal preferences and winning, and in recent years the Liberal flows seem to be more harshly against the Greens.

Thursday

The Liberals are out on leakage, falling 196 below Dawkins and 275 below Houston.  Now we just have Bridget Archer's preferences (many of them from other Liberals) to decide the final result.  As the above shows Labor has always gained on Liberal preferences in such situations in the past. (For those looking for a tiny morsel of hope for Dawkins, she did gain on Houston by two votes on Wood's leakage!)

2:40 I have word from a scrutineer that Houston won by 801 (yet to be updated on site).