Advance Summary
The "better Prime Minister" or "better Premier" score in Newspoll polling is a frequent subject of media focus. This article explores the history of Newspoll preferred leader scores at state and federal elections and during terms and finds that:
* Better Leader scores are skewed indicators that favour incumbents by around 14-17 points at both state and federal level.
* Better Leader scores add no useful predictive information to that provided by a regression based on polled voting intention.
* If anything, Prime Ministers with high Better Prime Minister leads may be more likely to underperform their polled voting intention, but this is already captured in the relationship between polled voting intention and actual results.
* At state level, leading as Better Premier is a worse predictor of election wins or losses than leading on two-party preferred and having a positive net satisfaction rating. This is because Better Premier is a weaker predictor of vote share than polled 2PP and is also more skewed as a predictor of election outcomes than either.
Showing posts with label predicting vote share. Show all posts
Showing posts with label predicting vote share. Show all posts
Tuesday, April 21, 2020
Friday, January 10, 2014
Wrong In Both Directions: Richo On Labor's Chances
Advance Summary
1. An article by Graham Richardson in The Australian argues that Labor has no real chance of winning the next election because the swing required to win on the Mackerras Pendulum is too large.
2. However, the comparisons Richardson makes disregard the relationship between a prior election result and the swing to (or against) Labor at the next election.
3. Indeed there is actually little if any historic relationship between the 2PP result at one federal election and the next.
4. Considering only the problem of gaining a swing of the size suggested by the pendulum, electoral history gives Labor a substantial (28%) chance of winning.
5. However this chance may be reduced if swings against first-term governments are usually smaller than a given base vote implies.
6. Furthermore, because Richardson relies on the Mackerras Pendulum, which is not adjusted for the personal votes of new sitting members, the target swing for Labor is probably higher than he thinks it is, and this reduces Labor's chances.
7. While it is therefore unlikely on paper that Labor will win the next election, it is unrealistic to assess it as a "virtually impossible" event on the basis of past electoral data.
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1. An article by Graham Richardson in The Australian argues that Labor has no real chance of winning the next election because the swing required to win on the Mackerras Pendulum is too large.
2. However, the comparisons Richardson makes disregard the relationship between a prior election result and the swing to (or against) Labor at the next election.
3. Indeed there is actually little if any historic relationship between the 2PP result at one federal election and the next.
4. Considering only the problem of gaining a swing of the size suggested by the pendulum, electoral history gives Labor a substantial (28%) chance of winning.
5. However this chance may be reduced if swings against first-term governments are usually smaller than a given base vote implies.
6. Furthermore, because Richardson relies on the Mackerras Pendulum, which is not adjusted for the personal votes of new sitting members, the target swing for Labor is probably higher than he thinks it is, and this reduces Labor's chances.
7. While it is therefore unlikely on paper that Labor will win the next election, it is unrealistic to assess it as a "virtually impossible" event on the basis of past electoral data.
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Tuesday, July 9, 2013
Poll Roundup and Seat Betting Watch - July 9-10
2PP Aggregate (Tuesday 9 July): 50.2 (-0.2 since last week) for Coalition
Individual Seat Betting: Labor favourites in 61 seats (+3 - Page, Eden-Monaro, Moreton)
Seat Total Market: Labor 65 seats (+7)
Last week I introduced a Seat Betting Favourites Watch series in which I intend to monitor the performance of seat betting markets in predicting results for specific seats in an election that is difficult to model. The reinstatement of Kevin Rudd as Prime Minister has resulted in a massive poll jump for a government that was clearly doomed under ex-PM Gillard, and nobody really knows whether the bounce will amplify before it declines. It is a good test for whether the markets can out-predict the polls at a time when the polls have good reason to be suspect as predictors, or merely follow them. I am personally sceptical of the reliability of betting as a predictive method.
This Week's Polls
This week we've had three national polls so far. Essential Report showed no change on last-week's one-week-sample 52-48 to Coalition. Newspoll was up one point for Labor to 50-50 and Morgan produced a generally dismissed headline figure of 54.5-45.5 to Labor. As is sometimes the case Morgan's use of respondent-allocated preferences was creating an out-of-whack result, and when preferences were allocated following the more reliable last-election model, the result was 52.5-47.5 to Labor.
Taken together these polls are slightly better for Labor than the post-change polls of the last two weeks and my own rough aggregate has moved from 50.4 to 50.2 for the Coalition. Mark the Ballot has Labor 50.5-49.5 ahead and a Bludgertrack update is expected tomorrow. (Update: Bludgettrack is at 50.5 for Labor as well.)
Individual Seat Betting: Labor favourites in 61 seats (+3 - Page, Eden-Monaro, Moreton)
Seat Total Market: Labor 65 seats (+7)
Last week I introduced a Seat Betting Favourites Watch series in which I intend to monitor the performance of seat betting markets in predicting results for specific seats in an election that is difficult to model. The reinstatement of Kevin Rudd as Prime Minister has resulted in a massive poll jump for a government that was clearly doomed under ex-PM Gillard, and nobody really knows whether the bounce will amplify before it declines. It is a good test for whether the markets can out-predict the polls at a time when the polls have good reason to be suspect as predictors, or merely follow them. I am personally sceptical of the reliability of betting as a predictive method.
This Week's Polls
This week we've had three national polls so far. Essential Report showed no change on last-week's one-week-sample 52-48 to Coalition. Newspoll was up one point for Labor to 50-50 and Morgan produced a generally dismissed headline figure of 54.5-45.5 to Labor. As is sometimes the case Morgan's use of respondent-allocated preferences was creating an out-of-whack result, and when preferences were allocated following the more reliable last-election model, the result was 52.5-47.5 to Labor.
Taken together these polls are slightly better for Labor than the post-change polls of the last two weeks and my own rough aggregate has moved from 50.4 to 50.2 for the Coalition. Mark the Ballot has Labor 50.5-49.5 ahead and a Bludgertrack update is expected tomorrow. (Update: Bludgettrack is at 50.5 for Labor as well.)
Wednesday, July 3, 2013
Seat Betting Favourites Watch - July 3
This is a series that may run on here sporadically from now til the federal election, the date of which is now unknown but considered most likely to be in either late August or late October. At this stage I'm thinking of posting an update in a fresh article weekly around the middle of the week, but the posting time will vary according to my other commitments. Also it may well be that someone else starts covering the same thing better, in which case I may just link to them and leave them to it.
Following the first week of Rudd-return polling, six polls by five companies have shown Labor somewhere in the range of 48-51% two-party preferred, with five of the six showing the government just behind. Seat models point to a very close election if the an election was proverbially "held today". The re-fired Bludgertrack projects 74-73-3 (ALP first), Mark the Ballot gives a uniform swing (or lack thereof) at 73-75-2 and Pollytics reports "My election simulation produces a similar result 76 seats to the ALP vs. 72 to the Coalition, with 2 Independents." (This is not the same as the 77-71-2 simulation I questioned as a slightly unsound extrapolation from its given data at the bottom of my previous post, and I assume it incorporates more data.)
Following the first week of Rudd-return polling, six polls by five companies have shown Labor somewhere in the range of 48-51% two-party preferred, with five of the six showing the government just behind. Seat models point to a very close election if the an election was proverbially "held today". The re-fired Bludgertrack projects 74-73-3 (ALP first), Mark the Ballot gives a uniform swing (or lack thereof) at 73-75-2 and Pollytics reports "My election simulation produces a similar result 76 seats to the ALP vs. 72 to the Coalition, with 2 Independents." (This is not the same as the 77-71-2 simulation I questioned as a slightly unsound extrapolation from its given data at the bottom of my previous post, and I assume it incorporates more data.)
Thursday, June 6, 2013
Newspoll Upfront Exclusion Rates Since 2002
Advance Summary
1. Some observers think that the proportion of voters who are indicated by Newspoll as "uncommitted" or "refused" gives Labor a much greater chance in the upcoming federal election, because the Government may attract a late swing from undecided voters.
2. The view that there is generally a late swing to an incumbent Government is false.
3. The view that there is usually a late swing to the party that is trailing is true, but it is not clear whether this is because there is a genuine "narrowing" effect, or whether this is because the Coalition tends to outperform its polling and the Coalition has often been the trailing party.
4. It is possible (and logical) that there is a link between increases in the Newspoll exclusion rate and poor polling for Labor, suggesting that when the party is performing poorly more of its voters become "uncommitted". However, the evidence on this is inconclusive.
5. While it is plausible that undecided voters will move back to the Government and improve its result by, say, two points, this is also something that may not happen at all.
6. The issue of uncommitted and refused rates is only relevant to the margin of an overwhelmingly likely Coalition win (assuming no Labor leadership change). There is nothing to suggest it is capable of turning the election.
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1. Some observers think that the proportion of voters who are indicated by Newspoll as "uncommitted" or "refused" gives Labor a much greater chance in the upcoming federal election, because the Government may attract a late swing from undecided voters.
2. The view that there is generally a late swing to an incumbent Government is false.
3. The view that there is usually a late swing to the party that is trailing is true, but it is not clear whether this is because there is a genuine "narrowing" effect, or whether this is because the Coalition tends to outperform its polling and the Coalition has often been the trailing party.
4. It is possible (and logical) that there is a link between increases in the Newspoll exclusion rate and poor polling for Labor, suggesting that when the party is performing poorly more of its voters become "uncommitted". However, the evidence on this is inconclusive.
5. While it is plausible that undecided voters will move back to the Government and improve its result by, say, two points, this is also something that may not happen at all.
6. The issue of uncommitted and refused rates is only relevant to the margin of an overwhelmingly likely Coalition win (assuming no Labor leadership change). There is nothing to suggest it is capable of turning the election.
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Saturday, June 1, 2013
How Common Is A Five-Point Swing In Under Four Months?
Advance Summary
1. The Gillard government now probably needs a swing back in public opinion of around 5% in three and a half months to win the federal election. [Update: After Monday's polls, it's even more than that.]
2. A recent article by Simon Jackman draws attention to swings of this magnitude, from one election to the next, being rare events that mainly (not exclusively!) accompany changes of power.
3. It is not correct to infer that swings of this size in a much shorter period are even less probable, because in fact 5-point swings within 16 weeks are commoner than 5-point swings between elections.
4. However, 5-point swings in shorter time periods typically result from temporary factors - leadership and event bounces, honeymoon effects, policy mistakes that are corrected, bad patches etc.
5. Fast swings that have occurred in the leadup to elections have usually washed out of the system partly or entirely by election day.
6. The past history of quick 5-point swings in polling provides no sound basis for belief that even an extreme event such as the S11 attacks or leadership change would save the Government now. (This does not mean it is impossible, just that there is no precedent.)
1. The Gillard government now probably needs a swing back in public opinion of around 5% in three and a half months to win the federal election. [Update: After Monday's polls, it's even more than that.]
2. A recent article by Simon Jackman draws attention to swings of this magnitude, from one election to the next, being rare events that mainly (not exclusively!) accompany changes of power.
3. It is not correct to infer that swings of this size in a much shorter period are even less probable, because in fact 5-point swings within 16 weeks are commoner than 5-point swings between elections.
4. However, 5-point swings in shorter time periods typically result from temporary factors - leadership and event bounces, honeymoon effects, policy mistakes that are corrected, bad patches etc.
5. Fast swings that have occurred in the leadup to elections have usually washed out of the system partly or entirely by election day.
6. The past history of quick 5-point swings in polling provides no sound basis for belief that even an extreme event such as the S11 attacks or leadership change would save the Government now. (This does not mean it is impossible, just that there is no precedent.)
Monday, May 20, 2013
EMRS - Greens hit new low
EMRS: Lib 54 (-1) Labor 28 (+5) Green 14 (-4) Ind 4 (+1)
Interpretation: Lib 53 Labor 33 Green 11 Ind 3
Outcome: Comfortable Liberal Majority Win (Approx 14 seats)
The May 2013 EMRS poll has been released and the trend graph for the headline figures is here. The headline figures have a history of overestimating Green support so there is a possibility that this poll is pointing to an even worse result for the party than indicated.
During the last polling period the Tasmanian forestry peace deal passed parliament and the party split on this major legislation on the floor of the House of Assembly, with four members voting in favour of the version returned by the Legislative Council and Bass Green MHA Kim Booth, long the least Labor-friendly and forestry-friendly of the five, voting against.
The poll shows the Liberal vote largely unaltered from the soaring levels of the last two polls, but what is interesting here is that the Labor vote is up to its highest headline level since November 2010 (not that 28% is any great triumph) while the Green headline rate is the lowest of this term in office, at 14%. The core Green vote, counting only firmly supportive voters, is shown at a ridiculously low 9%. I cannot remember it being this low for a very long time and suspect it would be necessary to go back to the earliest EMRS readings from the late 1990s to find a similar figure.
Interpretation: Lib 53 Labor 33 Green 11 Ind 3
Outcome: Comfortable Liberal Majority Win (Approx 14 seats)
The May 2013 EMRS poll has been released and the trend graph for the headline figures is here. The headline figures have a history of overestimating Green support so there is a possibility that this poll is pointing to an even worse result for the party than indicated.
During the last polling period the Tasmanian forestry peace deal passed parliament and the party split on this major legislation on the floor of the House of Assembly, with four members voting in favour of the version returned by the Legislative Council and Bass Green MHA Kim Booth, long the least Labor-friendly and forestry-friendly of the five, voting against.
The poll shows the Liberal vote largely unaltered from the soaring levels of the last two polls, but what is interesting here is that the Labor vote is up to its highest headline level since November 2010 (not that 28% is any great triumph) while the Green headline rate is the lowest of this term in office, at 14%. The core Green vote, counting only firmly supportive voters, is shown at a ridiculously low 9%. I cannot remember it being this low for a very long time and suspect it would be necessary to go back to the earliest EMRS readings from the late 1990s to find a similar figure.
Wednesday, March 13, 2013
Tasmanian Lower House: 25 or 35 Seats?
This article has been updated for elections from 2014 to 2025. Scroll down to the bottom for these updates.
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Advance summary (pre-2014 version):
1. The possibility of restoring the old 35-seat system in the Tasmanian House of Assembly is currently being discussed ahead of a motion to be moved by the Greens.
2. Looking at past election results and current polling, the 35-seat system is slightly more proportionally accurate, while the 25-seat system is slightly more prone to "over-represent" the major parties in comparison to vote share.
3. However, precise proportional representation in the Tasmanian context can easily be argued to be overrated anyway.
4. Of the elections considered (and a 2014 projection based on current polling), only in the case of 1998 did the choice of systems determine the election result.
5. Majority government is slightly more likely on average with 25 seats than with 35 seats, but in many scenarios the number of seats makes no real difference to its chances.
6. Strategic considerations favour the Greens supporting an increase in the number of seats and the Liberals opposing it, while for the Labor Party there are arguments on both sides.
7. The view that the Greens could plausibly win more seats than Labor at the next election if the 25-seat system is retained is not consistent with current polling.
8. It is not correct to blame too many problems in Tasmanian politics on the 25-seat system since politics under the 35-seat system was also very turbulent and crisis-prone during its last two decades.
1. The possibility of restoring the old 35-seat system in the Tasmanian House of Assembly is currently being discussed ahead of a motion to be moved by the Greens.
2. Looking at past election results and current polling, the 35-seat system is slightly more proportionally accurate, while the 25-seat system is slightly more prone to "over-represent" the major parties in comparison to vote share.
3. However, precise proportional representation in the Tasmanian context can easily be argued to be overrated anyway.
4. Of the elections considered (and a 2014 projection based on current polling), only in the case of 1998 did the choice of systems determine the election result.
5. Majority government is slightly more likely on average with 25 seats than with 35 seats, but in many scenarios the number of seats makes no real difference to its chances.
6. Strategic considerations favour the Greens supporting an increase in the number of seats and the Liberals opposing it, while for the Labor Party there are arguments on both sides.
7. The view that the Greens could plausibly win more seats than Labor at the next election if the 25-seat system is retained is not consistent with current polling.
8. It is not correct to blame too many problems in Tasmanian politics on the 25-seat system since politics under the 35-seat system was also very turbulent and crisis-prone during its last two decades.
Tuesday, February 19, 2013
EMRS - Liberals locking in support
Note to Tas or other interested readers: if you haven't already done so please vote in my not-a-poll for Best Tasmanian Premier of the last 30 years on the sidebar. Looks like the only poll Tasmanian Labor can still be confident of winning!
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EMRS: Liberal 55 Labor 23 (-4) Green 18 (+3) Ind 4 (+1)
Interpretation: Liberal 56 Labor 25 Green 15 Ind 4 (Ind figure depending on candidates)
Outcome "if election was held now": Liberal majority win (14-16 seats)
The new EMRS poll is out with a headline rate of Liberal 55 Labor 23 Greens 18 Ind 4. This is very similar to results polled in late 2011. The Greens have recovered some of the seven points lost last time (a loss which I suspected at the time was caused partly by sample anomalies) but it is still their equal second-worst result in this term of government. The EMRS headline figure habitually overestimates Green support and the figure from the table with undecideds included (Table 2) tends to provide a much better reading of Green support.
The very helpful trend tracking on the EMRS website shows that this is the Liberals' equal highest headline reading in this term, matching the 55 in August 2011 and the same in November 2012. But it is actually better than that for the party because their figure including undecided votes (46 - Table 2) is now at its highest level in EMRS history, compared to the 44 in Aug 2011 and the 43 in Nov 2012. This suggests the party is increasingly "locking in" the votes it needs to win majority government. Labor, on the other hand, is if anything shedding votes from the firmer end of its support base, with its Table 2 figure back to a miserable 17%, one point above its all-time low. The gap of 29 points at the firm end of the parties' support bases is the highest it has been and about twice the size needed for majority government. While I have assumed in my "interpretation" figure above that the voters who are undecided even after being asked what party they are leaning to will split evenly between the major parties, it is possible it could be even worse than this for Labor. If the remaining undecided voters break to the Liberals as well then a Liberal vote in the high 50s becomes possible.
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EMRS: Liberal 55 Labor 23 (-4) Green 18 (+3) Ind 4 (+1)
Interpretation: Liberal 56 Labor 25 Green 15 Ind 4 (Ind figure depending on candidates)
Outcome "if election was held now": Liberal majority win (14-16 seats)
The new EMRS poll is out with a headline rate of Liberal 55 Labor 23 Greens 18 Ind 4. This is very similar to results polled in late 2011. The Greens have recovered some of the seven points lost last time (a loss which I suspected at the time was caused partly by sample anomalies) but it is still their equal second-worst result in this term of government. The EMRS headline figure habitually overestimates Green support and the figure from the table with undecideds included (Table 2) tends to provide a much better reading of Green support.
The very helpful trend tracking on the EMRS website shows that this is the Liberals' equal highest headline reading in this term, matching the 55 in August 2011 and the same in November 2012. But it is actually better than that for the party because their figure including undecided votes (46 - Table 2) is now at its highest level in EMRS history, compared to the 44 in Aug 2011 and the 43 in Nov 2012. This suggests the party is increasingly "locking in" the votes it needs to win majority government. Labor, on the other hand, is if anything shedding votes from the firmer end of its support base, with its Table 2 figure back to a miserable 17%, one point above its all-time low. The gap of 29 points at the firm end of the parties' support bases is the highest it has been and about twice the size needed for majority government. While I have assumed in my "interpretation" figure above that the voters who are undecided even after being asked what party they are leaning to will split evenly between the major parties, it is possible it could be even worse than this for Labor. If the remaining undecided voters break to the Liberals as well then a Liberal vote in the high 50s becomes possible.
Friday, January 25, 2013
Federal Labor Getting Smashed In Bass
NOTE ADDED 12/7/13: This is an old article as should be clear from the absence of the word "Rudd". Conclusions in it no longer apply because of the change of Prime Ministership, and while it is likely Labor is still behind in the seat, fresh polling is needed.
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Just some quick notes about the ReachTEL poll of Bass (federal) that appeared in the Examiner today.
The findings are rather dramatic, with the Liberals' Andrew Nikolic supposedly leading Labor's Geoff Lyons 60.3-39.7 two-party preferred (based on preferences distributed as per the 2010 election), for a neat 17-point swing from the 2010 results. The Liberals are on 54.7%, otherwise known as an outright majority, Labor is on 26.7, the Greens are on 8.7, and about ten respondents believe Bob Katter's hat has been washed more recently than mine.
I think the 17-point swing is overcooking it just a little bit, which is not to say the swing won't be that big come election day. There is a very high vote for "Other" (7.9%), and in the absence of any known, specific force that would receive those "Other" votes, I believe those "Other" votes would include a number of soft Labor voters and possibly also some ultra-Green splitters. Thus I believe the preferences of these "Others" would actually favour Labor more than would be determined by using the 2010 election results, and that a more realistic reading of the swing might be, say, 15 points.
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Just some quick notes about the ReachTEL poll of Bass (federal) that appeared in the Examiner today.
The findings are rather dramatic, with the Liberals' Andrew Nikolic supposedly leading Labor's Geoff Lyons 60.3-39.7 two-party preferred (based on preferences distributed as per the 2010 election), for a neat 17-point swing from the 2010 results. The Liberals are on 54.7%, otherwise known as an outright majority, Labor is on 26.7, the Greens are on 8.7, and about ten respondents believe Bob Katter's hat has been washed more recently than mine.
I think the 17-point swing is overcooking it just a little bit, which is not to say the swing won't be that big come election day. There is a very high vote for "Other" (7.9%), and in the absence of any known, specific force that would receive those "Other" votes, I believe those "Other" votes would include a number of soft Labor voters and possibly also some ultra-Green splitters. Thus I believe the preferences of these "Others" would actually favour Labor more than would be determined by using the 2010 election results, and that a more realistic reading of the swing might be, say, 15 points.
Sunday, December 30, 2012
Uneven Swing to Liberals in Tasmanian State Election Polling
Advance summary:
1. Figures from three 2012 polls of Tasmanian state voting intention, show that swings between different electorates since the 2010 election are clearly not uniform.
2. Especially, Labor is polling very much better than the state swing suggests in Franklin, but generally worse in the northern seats and Lyons.
3. For a Liberal vote of around 50, the uneven swing pattern makes little difference to the seat total, with the party projected to win 13 seats (the barest possible majority).
4. For a Liberal vote well above 50, as in the November 2012 EMRS poll, the uneven swing pattern means that the party does not necessarily win more than 13 seats.
5. However the uneven swing pattern also makes it possible (but not at all likely at this stage) for the party to win as many as 17 seats.
1. Figures from three 2012 polls of Tasmanian state voting intention, show that swings between different electorates since the 2010 election are clearly not uniform.
2. Especially, Labor is polling very much better than the state swing suggests in Franklin, but generally worse in the northern seats and Lyons.
3. For a Liberal vote of around 50, the uneven swing pattern makes little difference to the seat total, with the party projected to win 13 seats (the barest possible majority).
4. For a Liberal vote well above 50, as in the November 2012 EMRS poll, the uneven swing pattern means that the party does not necessarily win more than 13 seats.
5. However the uneven swing pattern also makes it possible (but not at all likely at this stage) for the party to win as many as 17 seats.
Tuesday, December 25, 2012
Tasmanian State Election patterns since 1989
Secular season's greetings and best wishes for 2013. I intend to post on or about 31 Dec just to give some fluffy nonsense about annual site stats (annual being a misnomer as this site has existed for a bit over two months). Then on or about 1 Jan 2013 I will declare the winner of The Ehrlich for the "wrongest" prediction in any field of interest to me of or pertaining to the year 2012. Apart from that posts will continue to pop up when I have something I think is of interest to say, as time permits.
WONK ALERT (Category 4): This post is very wonky and statistical and contains 15 charts; I can't even remember if I included any jokes at all!
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Advance summary:
1. This post presents extensive vote-share data for the ALP, Liberals, Greens and collective "Rest" since the 1989 election, including breakdowns of swing patterns.
2. At least in the case of the Greens and Liberals, there is evidence that swings are not uniform. For these parties, swings in either direction tend to be greatest both in electorates where they perform well, and where their vote share in a given electorate at the last election was high. For these parties it may be reasonable to make some adjustments when predicting vote share in given electorates.
3. For the Labor Party there is less variation in average results between electorates and it is not clear whether there is a reliable pattern. For the Labor Party it may be easiest to just assume uniform swing except if there is convincing polling evidence otherwise.
4. A major issue in predicting the Green vote at the 2014 election will be whether or not there is a Wilkie-style independent standing.
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WONK ALERT (Category 4): This post is very wonky and statistical and contains 15 charts; I can't even remember if I included any jokes at all!
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Advance summary:
1. This post presents extensive vote-share data for the ALP, Liberals, Greens and collective "Rest" since the 1989 election, including breakdowns of swing patterns.
2. At least in the case of the Greens and Liberals, there is evidence that swings are not uniform. For these parties, swings in either direction tend to be greatest both in electorates where they perform well, and where their vote share in a given electorate at the last election was high. For these parties it may be reasonable to make some adjustments when predicting vote share in given electorates.
3. For the Labor Party there is less variation in average results between electorates and it is not clear whether there is a reliable pattern. For the Labor Party it may be easiest to just assume uniform swing except if there is convincing polling evidence otherwise.
4. A major issue in predicting the Green vote at the 2014 election will be whether or not there is a Wilkie-style independent standing.
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Friday, December 21, 2012
The Silly Season 2: End-Of-Year Poll Myths
Advance Summary
1. There has been some recent debate about the Government's polling position going into an election year.
2. The idea that this position has any special significance in projecting results is baseless.
3. While some pro-Labor sentiment has compared Labor's position now to Howard's end of year positions before elections that he won, in only one of three cases was Howard's position even arguably as bad.
4. Despite this there are earlier precedents for victory from seemingly quite poor end-of-year positions.
5. Analogies with Howard's position at the end of 2006 are fatally flawed because of the Labor leadership handover.
6. "Momentum" is a common concept in opinion poll commentary, but it has no basis in reality. Movements in one direction from poll to poll are most often followed by movements in the other, probably mostly as a result of random bouncing from sample to sample.
7. Attempts to define a poor end-of-year position for Labor are already outdated, having been brought into question by more recent polls. (This article gives reasons for considering Morgan Face 2 Face to be valid data and not ignoring it completely.)
This article also contains an unrelated section examining an argument by Peter Brent that a given level of voting intention is more durable for an unpopular leader than a popular one. There is not enough evidence to apply this to unpopular opposition leaders, and especially not to Tony Abbott at this time.
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In a previous article (Is The Silly Season Real?) I examined the idea that opinion polls behave strangely in December as many people swing into Santa mode and found that, at least in the case of Newspoll, there is no evidence to support it at all.
Another form of commentary that I have seen quite a lot of lately involves focus on the government's polling position at the end of the year and how this compares to that of previous governments, and what this might (supposedly) tell us about whether the government can win.
1. There has been some recent debate about the Government's polling position going into an election year.
2. The idea that this position has any special significance in projecting results is baseless.
3. While some pro-Labor sentiment has compared Labor's position now to Howard's end of year positions before elections that he won, in only one of three cases was Howard's position even arguably as bad.
4. Despite this there are earlier precedents for victory from seemingly quite poor end-of-year positions.
5. Analogies with Howard's position at the end of 2006 are fatally flawed because of the Labor leadership handover.
6. "Momentum" is a common concept in opinion poll commentary, but it has no basis in reality. Movements in one direction from poll to poll are most often followed by movements in the other, probably mostly as a result of random bouncing from sample to sample.
7. Attempts to define a poor end-of-year position for Labor are already outdated, having been brought into question by more recent polls. (This article gives reasons for considering Morgan Face 2 Face to be valid data and not ignoring it completely.)
This article also contains an unrelated section examining an argument by Peter Brent that a given level of voting intention is more durable for an unpopular leader than a popular one. There is not enough evidence to apply this to unpopular opposition leaders, and especially not to Tony Abbott at this time.
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In a previous article (Is The Silly Season Real?) I examined the idea that opinion polls behave strangely in December as many people swing into Santa mode and found that, at least in the case of Newspoll, there is no evidence to support it at all.
Another form of commentary that I have seen quite a lot of lately involves focus on the government's polling position at the end of the year and how this compares to that of previous governments, and what this might (supposedly) tell us about whether the government can win.
Tuesday, December 11, 2012
Is the Silly Season Real?
(Admin note to readers: jumpbreaks poll closed - thanks to those who voted - outcome at bottom of post)
Advance Summary
1. The view that a swing to the Coalition in the final Newspoll of 2012 was due to a general tendency for voters to "switch off" politics as Christmas approaches is disproven by historic evidence.
2. Comparisons between the December 2012 and December 2011 Newspolls on account of them having the same two-party preferred vote are simplistic and misleading because they fail to take into account surrounding trend data.
3. Although there has been a now clear and significant move to a substantial Coalition lead since early November, Labor's polling position in mid-December 2012 is not as bad as at the same time in 2011.
4. Leads similar to the Coalition's current lead have been held by many losing Oppositions five or six months prior to elections.
5. Whatever intuitive or subjective views different commentators hold, informed by data or otherwise, there is no known valid scientific basis for predicting the result of the next federal election at this stage, nor even for declaring a very strong favourite. This applies no matter who the leaders are.
Advance Summary
1. The view that a swing to the Coalition in the final Newspoll of 2012 was due to a general tendency for voters to "switch off" politics as Christmas approaches is disproven by historic evidence.
2. Comparisons between the December 2012 and December 2011 Newspolls on account of them having the same two-party preferred vote are simplistic and misleading because they fail to take into account surrounding trend data.
3. Although there has been a now clear and significant move to a substantial Coalition lead since early November, Labor's polling position in mid-December 2012 is not as bad as at the same time in 2011.
4. Leads similar to the Coalition's current lead have been held by many losing Oppositions five or six months prior to elections.
5. Whatever intuitive or subjective views different commentators hold, informed by data or otherwise, there is no known valid scientific basis for predicting the result of the next federal election at this stage, nor even for declaring a very strong favourite. This applies no matter who the leaders are.
Monday, December 10, 2012
Why Preferred Prime Minister/Premier Scores Are Rubbish
Note added 2020: This article now has a sequel. See Why Better Prime Minister/Premier Scores Are Still Rubbish
Advance Summary of this Article:
1. All pollsters who currently conduct Preferred Prime Minister/Premier polling but do not conduct approval rate polling for each leader, should conduct leader approval rate polling either instead of PPM/PP or as well as it.
2. Preferred Prime Minister scores have been historically maligned on the basis of a history of failing to predict election results. Although frequently reported in horse-race style by mainstream reporters, they are often dismissed as "beauty contest" scores by informed psephologists.
3. When a "house advantage" to the incumbent Prime Minister is taken into account, Preferred Prime Minister scores align better with election results and voting intention.
4. Preferred Prime Minister ratings are driven by, and lag behind, Prime Ministerial approval ratings, and are not especially good forecasters of future poll results.
5. The focus on Preferred Prime Minister/Premier scores not only leads to misleading commentary but also obscures useful data that are reflected in approval ratings but lost in scores that just compare leaders.
Disclaimer: This article only applies to the usefulness (or otherwise) of comparisons between existing party leaders, such as PM vs Opposition Leader. It does not (necessarily) apply to surveys comparing hypothetical leaders of the same party, or comparing an existing leader of a party with a potential leader of another, or to surveys like the recent Galaxy 4-way preferred prime minister poll.
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Many pollsters ask voters to decide which of the Prime Minister and Opposition Leader they would prefer to be Prime Minister. At state level, the same thing happens with Preferred Premier polling, and some pollsters (this includes you, EMRS) poll Preferred Premier but do not poll approval ratings.
The actual value of Preferred Prime Minister scores has long been a source of difference of opinion, and at times abuse, between some parts of the mainstream political media and the online "psephosphere". In 2007 this got particularly heated when some mainstream journalists kept arguing that the election was in the balance because John Howard was not far behind Kevin Rudd as Preferred Prime Minister (Howard trailed Rudd consistently from mid-Feb 2007 onwards, but only by an average of seven points, at times closing to as close as one.)
Advance Summary of this Article:
1. All pollsters who currently conduct Preferred Prime Minister/Premier polling but do not conduct approval rate polling for each leader, should conduct leader approval rate polling either instead of PPM/PP or as well as it.
2. Preferred Prime Minister scores have been historically maligned on the basis of a history of failing to predict election results. Although frequently reported in horse-race style by mainstream reporters, they are often dismissed as "beauty contest" scores by informed psephologists.
3. When a "house advantage" to the incumbent Prime Minister is taken into account, Preferred Prime Minister scores align better with election results and voting intention.
4. Preferred Prime Minister ratings are driven by, and lag behind, Prime Ministerial approval ratings, and are not especially good forecasters of future poll results.
5. The focus on Preferred Prime Minister/Premier scores not only leads to misleading commentary but also obscures useful data that are reflected in approval ratings but lost in scores that just compare leaders.
Disclaimer: This article only applies to the usefulness (or otherwise) of comparisons between existing party leaders, such as PM vs Opposition Leader. It does not (necessarily) apply to surveys comparing hypothetical leaders of the same party, or comparing an existing leader of a party with a potential leader of another, or to surveys like the recent Galaxy 4-way preferred prime minister poll.
--------------------------------------
Many pollsters ask voters to decide which of the Prime Minister and Opposition Leader they would prefer to be Prime Minister. At state level, the same thing happens with Preferred Premier polling, and some pollsters (this includes you, EMRS) poll Preferred Premier but do not poll approval ratings.
The actual value of Preferred Prime Minister scores has long been a source of difference of opinion, and at times abuse, between some parts of the mainstream political media and the online "psephosphere". In 2007 this got particularly heated when some mainstream journalists kept arguing that the election was in the balance because John Howard was not far behind Kevin Rudd as Preferred Prime Minister (Howard trailed Rudd consistently from mid-Feb 2007 onwards, but only by an average of seven points, at times closing to as close as one.)
Tuesday, November 20, 2012
Attitudes To Attributes (Not Great News For The Greens)
Advance summary
1. Recent polling on voter views of the importance of a list of issues, and which parties are best trusted on those issues, shows that many voters regard a range of parties as having policy strengths in different areas, rather than assuming their preferred party is always right.
2. Party trust scores, when weighted by the perceived importance of issues, produce surprisingly accurate predictions of party vote share over the last two and a half years.
3. The Greens' current mediocre polling position, especially compared to before the 2010 election, is probably connected with the party neither "owning" key issues as strongly as it used to, nor being able to convince voters that those issues are important.
1. Recent polling on voter views of the importance of a list of issues, and which parties are best trusted on those issues, shows that many voters regard a range of parties as having policy strengths in different areas, rather than assuming their preferred party is always right.
2. Party trust scores, when weighted by the perceived importance of issues, produce surprisingly accurate predictions of party vote share over the last two and a half years.
3. The Greens' current mediocre polling position, especially compared to before the 2010 election, is probably connected with the party neither "owning" key issues as strongly as it used to, nor being able to convince voters that those issues are important.
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