Federal Election 2010

Hung Parliament on 52-48 Scenario

August 17

Some say that with the state of the national polls
eg Newspoll ALP 52-48 it is impossible for
the ALP to not win majority government.

However, it is perfectly possible for the ALP
to win only 75 seats with 52% of the vote.

The following
scenario sets out how this might happen and
is roughly consistent with the latest national polls,
state-wide polls. individual seat polls and
individual seat betting markets.

State-by-state.

NSW (average 1.5% swing to Liberals, ALP end up on 51.9%)
Loss of Macquarie, Robertson, Gilmore, Macarthur
Bigger swing in Lindsay (-7%) loss
Lesser swings in Bennelong (-0.6%) hold

Qld (average 3.7% swing to LNP, ALP end up on 46.9%)
Loss of Flynn, Dickson, Dawson, Herbert
Bigger swing in Leichhardt (-5%) loss
Lesser swing in Forde (-2.5%) hold
Lesser swing in Longman (+2%) hold

Vic (average 3.2% swing to ALP, ALP end up on 57.2%)
Gain of McEwen
Lesser swing in La Trobe (1% to Libs) Lib hold
Greens win Mebourne

WA (average 0.3% swing to ALP, ALP end up on 47.0%)
Lesser swing in Swan (4% to Libs) Lib gain
Lesser swing in Hasluck (1% to Libs) Lib gain

SA (average +0.1% swing to ALP, ALP on 52.3%)
no change

Tas (av +0.6% swing to ALP)
no change

ACT (av 0% swing to ALP)
no change

NT (av -0.3% swing to Libs, ALP on 55.1%)
ALP lose Solomon

Overall TPP is 52.0%
(0.7% swing to Coalition)

Overall seat result:
ALP 75, Lib 71, Ind 3, GRN 1

Hung Parliament

Federal Election 2010: Analysis of Individual Seat Betting Aug 17th

Likely state of parties after the election according to the individual
seat odds of Sportingbet as of this morning (aug 17).

Overall situation: around ALP 75, LNP 71 , Ind 3, Green 1 => Hung Parliament

Note that the odds have changed a little over the last few days.
There are now less seats which are close to 50-50 probability.
There has also been a bit of a move by a few NSW seats to the
Coalition.

The change to a hung parliament today is a move
in the opposite direction to the moves on
the betting market for the overall government.

Details (according to current odds):

1)
ALP to lose Melbourne to the Greens
(Prob Green win =55%, Prob ALP =34%)

2)
ALP have 63 safe seats including Eden-Monaro and Longman.

3)
ALP look very likely to retain a further 7 of the following 9
(in which they have good odds of retaining):
Greenway (which was Lib before redistribution), Page, Dobell,
Bonner, Petrie, McEwen(a gain), Bass, Deakin, Brisbane,
But they may lose 2.

4)
ALP should be able to win 2 of the following 3 seats as they are just ahead:
Corangamite, Forde, Bennelong
But they may not get 1 of these.

5)
ALP should be able to win at least 2 of the following 5 seats
where they are just behind, but they will most likely lose
the other 3:
Hasluck(ALP), Solomon(ALP), Lindsay(ALP),
Herbert(Lib/notional ALP), La Trobe (Lib).


6)
ALP should be able to win 1 of the following 5 seats where they are behind
but have the cumulative probability of one win:
Hughes(Lib), Macarthur(Lib, notional ALP), Canning(Lib), Swan(Lib, notional ALP), Dawson(ALP)

7)
There are 6 seats which were in doubt but now seem likely
to be won by the Liberals. Likely 0 to ALP:
Macquarie(Lib), Gilmore(Lib, notional ALP), Boothby(Lib),
Dickson(Lib, notional ALP), Ryan(Lib), Flynn(Lib)

7)
There are 55 safe L/NP seats.

8)
There are 3 safe independents.

9)
Note that there are 75 seats which the odds say that the
ALP are more likely to win than not win, but because there
are more seats just on the ALP side than just on the
Coalition side, the expected number of wins is
a bit less 74.7.

Total 150 seats. Here is a table (click for a larger version).

























This also includes estimates of swings to the ALP
based on the bookies odds.

Federal Election 2010: Poll of Polls 15th August

We've had a few polls published this weekend.

1)
There are also the latest individual seat betting odds.
http://dr--good.blogspot.com/2010/08/federal-election-2010-analysis-of_14.html

2)
There is a Neilsen 53-47
http://blogs.crikey.com.au/pollbludger/2010/08/13/nielsen-53-47-to-labor/
showing a 0.3% swing to ALP if taken on a uniform national
basis.


3)
There is a Morgan phone poll 51-49 with state by state breakdowns
http://www.roymorgan.com/news/polls/2010/4559/
It suggests swings of
-6.3, +4.2, -3.9, +0.8, -0.4, -3.7 across NSW, Vic, Qld, WA, SA
and Tas respectively. I also include a recent individual seat poll
by Morgan which gives Solomon to the CLP.

4)
There is a newspoll marginals poll
http://blogs.crikey.com.au/pollbludger/2010/08/14/newspoll-marginals-poll-nsw-queensland-victoria/
It suggests swings of
-1.3, +6.2, -3.4 across NSW, Vic, Qld, respectively

5)
There is the dodgy monster Galaxy
http://blogs.crikey.com.au/pollbludger/2010/08/15/galaxy-marginals-polls-and-the-rest/
which is pointing towards an ALP 51-49 TPP but
some claim also suggests swings of
-2.4, +1.6, -5.4, -2.1, 0 across NSW, Vic, Qld, WA and SA respectively.
I think that they have not chosen sensible electorates
to get a picture of the statewide swings but anyway ...

Let's compare their predictions.

Here is a table of electorates with the respective
predictions and a total at the end of how many
of our 5 recent oracles, are predicting an ALP
win. Click for a bigger version. This only includes
marginals.























There are 57 safe ALP seats not listed so
you can use the number in the first
column to total up the overall ALP
wins. ( I don't include Melbourne)

Looks like about 79 to the ALP plus or
minus a few.

Federal Election 2010: Analysis of Individual Seat Betting Aug 15th

Likely state of parties after the election according to the individual
seat odds of Sportingbet as of this morning (aug 15).

Overall situation: around ALP 76, LNP 70 , Ind 3, Green 1 => ALP majority government

Details (according to current odds):

1)
ALP to lose Melbourne to the Greens
(Prob Green win =55%, Prob ALP =34%)

2)
ALP have 63 safe seats including Eden-Monaro and Longman.

3)
ALP look very likely to retain a further 7 of the following 10
(in which they have good odds of retaining):
Greenway (which was Lib before redistribution), Page, Dobell,
Bonner, Petrie, McEwen(a gain), Deakin, Brisbane, Bennelong, Lindsay
But they may lose 3.

4)
ALP should be able to win 3 of the following 4 seats as they are just ahead:
Forde, Bass, Corangamite, Hasluck
But they may not get 1 of these.

5)
ALP should be able to win at least 2 of the following 6 seats
where they are just behind, but they will most likely lose
the other 4:
Solomon(ALP), Hughes(Lib), Herbert(Lib), Macarthur(Lib),
Swan(Lib), Macquarie(ALP)

6)
ALP may win 1 of the following 9 seats where they are behind
but have a significant probability of a win (i.e. it adds up over the 9
seats):
La Trobe, Canning, Dawson(ALP), Bowman, Leichhardt, Gilmore,
Boothby, Dickson, Ryan

7)
There are 54 safe L/NP seats.

8)
There are 3 safe independents.

9)
Note that there are 77 seats which the odds say that the
ALP are more likely to win than not win, but because there
are more seats just on the ALP side than just on the
Coalition side, the expected number of wins is only 76.

Total 150 seats. Here is a table (click for a larger version).
























This also includes estimates of swings to the ALP
based on the bookies odds.

Federal Election 2010: Analysis of Individual Seat Betting Aug 11th

Likely state of parties after the election according to the individual
seat odds of Sportingbet as of today (aug 11).

Overall situation: around ALP 76, LNP 70 , Ind 3, Green 1 => ALP majority government

Details (according to current odds):

1)
ALP to lose Melbourne to the Greens
(Prob Green win =55%, Prob ALP =34%)

2)
ALP have 63 safe seats including Greenway (which was Lib before redistribution)
and Eden-Monaro.

3)
ALP look very likely to retain a further 7 of the following 9
(in which they have good odds of retaining):
Booner, Page, Longman, Petrie, Bennelong, Deakin, Dobell, Brisbane, McEwen(a gain)
But they may lose 2.

4)
ALP should be able to win 3 of the following 5 seats as they are just ahead:
Bass, Corangamite, Forde, Lindsay, Hasluck
But they may not get 2 of these.

5)
ALP should be able to win at least 2 of the following 8 seats
where they are just behind, but they will most likely lose
the other 6:
Macarthur(Lib), Solomon(ALP), Hughes(Lib), Herbert(Lib), Dickson(Lib), Flynn(ALP),
Swan(Lib), Macquarie(ALP)

6)
ALP may win 1 of the following 8 seats where they are behind
but have a significant probability of a win (i.e. it adds up over the 8
seats):
Leichhardt(ALP), Canning, La Trobe, Robertson (ALP),
Dawson(ALP), Bowman, Boothby, Gilmore

7)
There are 53 safe L/NP seats.

8)
There are 3 safe independents.

9)
Note that there are 77 seats which the odds say that the
ALP are more likely to win than not win, but because there
are more seats just on the ALP side than just on the
Coalition side, the expected number of wins is only 76.

Total 150 seats. Here is a table (click for a larger version).
























We can also roughly estimate the expected swings by using the
seat odds and current margin. See the last column.

How good are the Individual Seat Odds from the Bookies at predicting the winner of the individual seat?

Below are some results from the 2007 election. (Click for a larger image)

These show some of the seats with the winner, two-party preferred vote
after the election and before and the swing away from ALP. They
show the Sportingbet probability of ALP winning the seat as offered on
Nov 23rd, election eve. Thanks Simon Jackman for keeping that
data.

We also see the winner of the seat according to three different prediction
methods.

First is by using the uniform national swing reported in the Newspoll
of Nov 23.

Next is the winner according to Sportingbet. (Sportingbet didn't
give odds for Hinkler and Kennedy like many seats that
were assumed to be very safe. So we just assume that
Sportingbet was assuming that the current holder would
win.)

Last is the winner according to state by state uniform swings
as predicted by Newspoll on Nov 23rd.

There are 26 seats listed. All three methods agreed in their predictions
on all the other 124 seats and they were all correct
in those predictions. These are the seats where at least one method
got the winner wrong.





















So what was the best way to predict the winner of a seat?

Here are the results. Recall that the ALP won 83 of the
150 seats. (They won 110 of the seats not listed here).

Method 1: (use the latest Newspoll and assume a uniform
national swing)
You get 134 predictions correct and you think the ALP will
win 75 seats.

Method 2: (use sportingbet odds for each set)
You get 138 predictions correct and you think the ALP will
win 81 seats.

Method 3: (Use the latest Newspoll state by state swings,
with the national swing for NT, ACT and Tas)
You get 132 predictions correct and you think that the ALP
will win 83 seats.

So, the most accurate predictor of individual seat winners
was to use the bookies' odds.

You can do some more work and find out the expected
number of seats won by each party but we'll come
back to that later.

Federal Election 2010:
Analysis of Individual Seat Betting Aug 9th

Expected Swings in the most marginal seats.

The odds of winning individual seats tell us something about the swings expected in those seats. Eg, 50-50 odds tell us that the bookies and their punters expect the final result in that seat to be close to even. More on this in a future post.

Here are the swings (to the ALP) expected according to today's sportingbet odds.





















(click on the table to see a bigger image)

Federal Election 2010: Analysis of Individual Seat Betting Aug 8th

Likely state of parties after the election according to the individual
seat odds of Sportingbet as of today.

Overall situation: around ALP 77, LNP 69 , Ind 3, Green 1 => ALP majority government

Details (according to current odds):

1)
ALP to lose Melbourne to the Greens
(Prob Green win =50.4%, Prob ALP =36.7%)

2)
ALP have 63 safe seats including Greenway (which was Lib before redistribution)
and Eden-Monaro.

3)
ALP look very likely to retain a further 7 of the following 9
(in which they have good odds of retaining):
Lindsay, Page, Bonner, Longman, Petrie, Bennelong, Dobell, Deakin, Brisbane
But they may lose 2.

4)
ALP should be able to win 4 of the following 6 seats as they are just ahead:
Forde, Bass, McEwen(a gain), Hasluck, Hughes(a gain), Corangamite
But they may not get 2 of these.

5)
ALP should be able to win at least one of the following 4 seats
where they are just behind, but they will most likely lose
the other 3:
Solomon(ALP), Macarthur(Lib), Herbert(Lib), Dickson(Lib)

6)
ALP may win 2 of the following 11 seats where they are behind
but have a significant probability of a win (i.e. it adds up over the 11
seats):
Bowman, Flynn(ALP), Swan, Ryan, Macquarie(ALP), Leichhardt(ALP), Paterson,
La Trobe, Canning, Robertson(ALP), Dawson(ALP)

7)
There are 53 safe L/NP seats.

8)
There are 3 safe independents.

Total 150 seats.

Federal Election 2010: Analysis of Individual Seat Betting Aug 3rd

Likely state of parties after the election according to the individual
seat odds of Sportingbet as of today.

Overall situation: around ALP 77, LNP 69 , Ind 3, Green 1 => ALP majority government

Details (according to current odds):

ALP to lose Melbourne to the Greens

ALP have 64 safe seats including Greenway (which was Lib befre redistribution).

ALP look very likely to retain a further 7:
Bonner, Page, Longman, Dobell, Bennelong, Deakin and Brisbane

ALP should be able to hold 3 of the following 4 seats as they are ahead:
Petrie, Forde, Bass, Hasluck

ALP should be able to hold at least one of the following 3 ALP held seats
where they are even, close or just behind, but they will most likely lose
the other 2:
Corangamite, Solomon, Leichhardt,

Other likely ALP losses are:
Macquarie, Flynn, Dawson, Robertson

ALP likely to gain about 2 of the following seats:
McEwen, Hughes, Herbert, Macarthur

ALP probably won't gain any of the following seats
although they are close:
Dickson, Bowman, Swan

There are 55 safe L/NP seats.

There are 3 safe independents.

Total 150 seats.