Update 21:31

New update with 69% of the vote counted.  Results now a lot more certain.

Total seats for National party.

National to win 60 to 63 seats.

Total seats for the Labour party.

Labour to win 32 to 35 seats.

Total seats for the Green party.

Green party to win 13 to 14 seats.

Scenario analysis.

A National PM.

Update 20:45

Still too early to make comments on the electorate results, or results at the candidate level, but things are now stable enough to make national-level predictions.

Histogram showing the total number of seats National are expected to win in parliament.

Simulated distribution of seats for National now showing double peak. National a lot better off if NZF don’t make 5% than they are if they do.

Scenario analysis.

National still predicted to lead government, but probability of majority rapidly falling. There is now a reasonable probability that the Maori party will hold balance of power.

Update 20:21

Election results now coming from Elections NZ, not TVNZ.

NZF creeping up in the new simulated percentages, as the polls are progressively given relatively less weight and Elections NZ results given relatively more weight.

Raw party vote percentages for each party::
National : 49.47 % +- 2.39 %
Labour : 28.56 % +- 2.16 %
Green : 11.82 % +- 1.34 %
ACT : 1.85 % +- 0.33 %
Maori : 1.08 % +- 0.24 %
Progressive : 0.04 % +- 0.03 %
United : 0.59 % +- 0.24 %
NZ First : 4.22 % +- 0.73 %
All Other : 2.06 % +- 0.34 %
TOTAL : 100.00 % +- 0.00 %

Update 19:39

Blackout over.

I will be making periodic updates tonight using a mix of data from the pre-election polls, combined with updates from TVNZ as they come in. Updates from TVNZ will be taken as is, and for the uncounted vote I will assume it falls according to the polls, with a bit of a fudge factor to counteract the bias from early reporting electorates. Electorates will also be awarded to the winning party where known, otherwise they will be calculated as usual according to the Uniform National Swing model.

It’s a pretty rough system, but I think better than doing nothing and waiting until 1AM before we start hypothesising on coalition outcomes.

I won’t be beating any of the TV stations for electorate level predictions, but hope to give them a run for their money on the composition of parliament. We’ll see if it works.

Raw party vote percentages for each party::
National : 49.44 % +- 2.52 %
Labour : 28.81 % +- 2.28 %
Green : 11.61 % +- 1.41 %
ACT : 1.85 % +- 0.35 %
Maori : 1.03 % +- 0.26 %
Progressive : 0.04 % +- 0.03 %
United : 0.56 % +- 0.26 %
NZ First : 3.88 % +- 0.77 %
All Other : 2.77 % +- 0.36 %
TOTAL : 100.00 % +- 0.00 %

Democracy Ahoy!

Never voted in NZ before, and haven’t been here for an election since I was 15. Getting kind of a weird vibe.

Democracy ahoy.

Election Day Welcome

Looking at the stats there is a lot of traffic today coming from seach engines, presumably first time visitors. Welcome! Make yourselves at home.

Most of you will find what you are looking for on the front page, and for those of you who arrived after a search including the word “epsom”, I’m sure Google will send you where you want to go.

For those interested I am on Twitter at @kiwipollguy, and will be commenting tonight as the results come out. I was hoping to have live results updates and see if I could beat the TV News in calling the election, but it will require a few hours coding, and the weather’s looking great, so it may end up just being commentary.

Maori Party Tactical Voting

There is a lot of information out there on tactical voting, some of it good, and some not so good. One common misconception though is that there is no point in voting for the Maori party because a vote for the Maori party is a wasted vote, in the sense that it will not help elect anybody to parliament because of the Maori party overhang. This is correct in the technical sense, but misses the point a bit.

There will be an overhang in parliament after the election, which will be caused partly by the Maori party winning more electorate seats than they would be entitled to given their share of the vote. However, a vote for the Maori party, whilst being a wasted vote, will work to reduce this overhang by removing seats from other parties.

Consider the following two scenarios:

1. The first scenario is that predicted by current polling.  In this scenario the Maori party win 4.8 +-/ 0.8 seats in a parliament with a total of 124.8 +-/ 1.1 seats.
2. In Scenario #2 we assume the turnout is exactly the same as the last election: 2,344,566 votes.  We then assume that an additional 10,000 people who would have otherwise stayed home instead turn out to vote for the Maori party.  What happens now?  The overall effect of these extra 10,000 voters on the party vote isn’t huge, but the effect on the seat distributions is non-negligible.  In this scenario the Maori party still win 4.8 +-/ 0.8 seats in parliament, exactly the same as in Scenario #1. But the total size of parliament drops to a total of 124.2 +-/ 1.0 seats due to a reduction in the overhang.

What happens to the missing 0.6 seats under Scenario #2?  They come from the other parties with probabilties in proportion to their party votes: National would lose approximately 0.3 seats, Labour would lose approximately 0.2 seats, and the Green party would lose approximately 0.1 seats.

It might not seem a huge difference given a hypothetical situation with an extra 10,000 voters rustled up out of nowhere.  But when you consider the cost of an extra backbencher’s salary, about $141,800, this works out at an expected saving for the NZ government $9 per year for each of the next three years for each additional party vote for the Maori party.

Wasted vote or otherwise, politically-neutral voters who want to cast a protest vote could do a lot worse than party vote Maori party.  There is a difference between a “wasted” vote and an ineffectual vote.

Final Pre-Election Effective Party Lists

Final effective party lists for the 2011 NZ General Election, based on candidate election probabilites post below.

This lists order candidates for each party by the probabilty of being elected to parliament as the lowest ranked successful list candidate for their party. In other words, the probability that a party vote for this party will go towards electing this candidate.

For more information please refer to the original effective party lists post.

Effective party list for the National party.

A vote for the National party is a vote for Joanne HAYES (41%), Claudette HAUITI (35%), Sam COLLINS (14%), or Aaron GILMORE (5%).

Effective party list for the Labour party.

A vote for the Labour party is a vote for Deborah MAHUTA-COYLE (36%), Stuart NASH (24%), Rick BARKER (24%), Carmel SEPULONI (7%) or Brendon BURNS (6%).

Effective party list for the Green party.

A vote for the Green party is a vote for David HAY (63%) or James SHAW (35%).

Effective party list for the ACT party.

A vote for the ACT party is a vote for Don Brash (71%) or Catherine ISAAC (26%).

Effective party list for the Maori party.

A vote for the Maori party is a wasted vote, in the sense that it will not help elect anybody to parliament because of the Maori party overhang.

Final Pre-Election Candidate Election Probabilites

Shown below are the updated Candidate Election Probabilities based on tonight’s polling update. Please click to embiggen. For an explanation of the methodology please see the original post on individual candidate election probabilities.

(Should also point out that I’ve made a couple of manual tweaks to the list this time, as it is the last one to be published before the election. I have given the Progressive party’s votes in Wigram to the Labour candidate, who is widely considered to be the most likely to benefit from Jim Anderton not standing, and have given votes to Hone Harawira in Te Tai Tokerau to reflect his likelihood of winning there.)

1. Rank: From 0 to 899, gives the respective candidate’s relative likelihood of being elected, and is ordered firstly by probability to be elected, and then by party code and list ranking where there is a tie.  Candidates are shown in the table ordered by “rank”.
   
2. Party Code : A unique code for each political party.  Parties are numbered 0~7, and ordered firstly by the number of seats won in the 2008 NZ General Election, and secondly by the number of party votes received.
3. Party
   
4. List Ranking
5. Name: The name of the candidate (as given on the Elections New Zealand website, where available).
6. Electorate: The electorate the candidate will stand in. For list-only candidates this will read “list only.”
7. Electorate Code : A unique code for the electorate.  Electorates are numbered in alphabetical order, with general electorates (#0 ~ #62) preceding Maori electorates (#63 ~ #69). If the candidate is a list-only candidate candidate this code will take the value -1.
8. Elect. 08: Blank, for the moment.
9. Prob. Electorate: Probabilty of being elected to parliament as an electorate candidate.
   
10. Prob. List: Probabilty of being elected to parliament as a list candidate.
    
11. Prob. Combined: Combined probabilty of being elected to parliament as an electorate candidate.
    
12. Prob. Last: Probabilty of being elected to parliament as the lowest ranked successful list candidate for their party.  In other words, the probability that a party vote for this party will go towards electing this candidate.
    

Probabilities for each candidate to be elected to Parliament through their electorate, through the party list, and the overall combined probability. (PNG, 760kB)

Final Pre-Election Polling Update

The last two polls to make it out in time for the election are the overnight Roy Morgan Research poll and this morning’s Herald-Digipoll

The updated polling averages now have National on 51.4% +/- 0.5%, Labour on 27.1% +/- 0.5%, the Greens on 11.2% +/- 0.3%, NZF on 3.7% +/- 0.2%, ACT on 1.9% +/- 0.2% and the Maori Party on 1.1% +/- 0.2%. Increases for the Greens and New Zealand First are statistically significant relative to the previous update from last night, although only just. Changes for others not statistically significant.

As usual, the two graphs below summarise the polling averages for the party vote after the new poll. The horizontal axes represent the date, starting 60 days before the 2008 NZ General Election, and finishing on day of the 2011 NZ General Election (26 November 2011). The solid lines with grey error bands show the moving averages of the party vote for each party, and circles show individual polls with the vertical lines representing the raw statistical errors.

Party vote support for the eight major and minor NZ political parties as determined by moving averages of political polls. Colours correspond to National (blue), Labour (red), Green Party (green), New Zealand First (black), Maori Party (pink), ACT (yellow), United Future (purple), and Progressive (light blue) respectively.

Party vote support for the Green party as determined by moving averages of political polls.

Party vote support for the five minor NZ political parties as determined by moving averages of political polls. Colours correspond to New Zealand First (black), Maori Party (pink), ACT (yellow), United Future (purple), and Progressive (light blue) respectively.

As far as the election results go, National is still predicted to win an outright majority.

As always, please check the Graphs page for further simulation results.

Please also check back later this evening, as I will have a new post with the updated candidate election probabilites and effective party lists.