What we think and how we vote

11:54 Jul 28, 2016 45

by David Hood

The data for the 2014 New Zealand Election Survey was recently released for the general public to make of it what they will, which in the modern world of home data analysis is like parachuting a gazelle into a pride of lions.

One thing I decided to explore is how representative the ideas of "Left" and "Right" are in the New Zealand of today. They are terms that get bandied around, and people and parties get pinned into place with, but do they actually matter?

One of the questions in the survey asks people to rate themselves on a spectrum of Leftmost (0) to Rightmost (10) with 5 being the centre of the spectrum. We can join that tidbit of information to information about what political party did the person declare voting for with their party vote, and so check the self-identified Left-Rightness by party preference.

For those not used to box plots the rectangle is where the middle fifty percent of voters for the party rate themselves. The black line in the centre of each rectangle is the median voter. The red-blue dashed line is the "centre" of the spectrum. The vertical thickness of the rectangle is the number of votes.

The smaller the number of voters (the thinner the rectangle) the more the results become sensitive to what one or two voters chose on the eleven-point scale. So, for this post, I am making the arbitrary decision to not bother talking about the parties with less than 0.5% of the vote in the survey responses (that is 14 people in the survey). Bye-bye for now to United Future, ACT, ALCP, and similar.

There are some not too surprising things on view here: not many people view themselves as extreme, people who vote Labour tend to see themselves on the left, people who vote National tend to see themselves on the right. New Zealand First and Māori Party voters see themselves as the generally most centrist. I do want to draw attention to the way that Labour voters tend to see themselves as closer to the middle than National voters.

We can build on this by comparing what people think of themselves with what people think of the party they voted for.

I dropped Internet/Mana for this graph, as I had separate ratings for Internet and Mana and that just made it complicated. The Green party, while having the same median as its voters, is given support by those that consider it to the left of their positions. Labour has an almost freakish match between its voters' self-perceptions and the perception of the party (I actually went and checked for mistakes due to that. Didn't find any). Māori party voters see themselves as slightly more centrist than the party. New Zealand First, while having the same median as its voters, draws support is given support by those that consider it to the right of their positions. Both National and Conservative voters tend to view the party as being to the right of the voters.

Rather than looking at it as bar graph summaries, we can look at the cloud of individual points of the self-rating on the x axis and the voters rating of the party they voted for on the y axis.

Putting aside the few isolated very odd results that may indicate people may have misunderstood the question, there are a number of observations about general patterns.

Conservative voters mirror National voters. Conservative and National voters tend to be centre to right, and see the parties they are voting for as more rightwing.

New Zealand First voters cluster at the centre and spread to the right, while the centrist NZF voters see the party as to the right, the right NZF voters see the party as to the left.

Māori Party voters and party form a central clump, with a tendency to rate the party near to themselves (most of the points are near the diagonal).

Labour voters are spread through the spectrum and concentrated in the centre left. Whatever Labour voters think of themselves tends to be around what they think of the party – if you are left and vote Labour then you describe Labour left, if you are right and vote Labour then you describe Labour as right. Green voters tend to centre to left, while rating the party left of where they are.

This does raise the (to me) interesting point that some people are voting a party they see as long way from themselves on a left-right spectrum. So how relevant are traditional left/right models in MMP New Zealand- clearly people understand them and can place themselves and parties- but to what extent does this actually matter in voting behaviour.

We can check this by rearranging the data a bit, and asking the question "What percentage of each parties voters voted for the party that they rated closest to them on the left/right spectrum?". The core idea here is that if you are skipping over a party that it is most in your "class interest" to vote for, then that suggests class interests are not your motivating factor.

Before revealing the results I'm going to preemptively say this is not an either/or- you might still be voting for a nearby party in left/right terms, just not the most nearby party or parties. But as you are not voting for the party that is, by your own opinion, the closest fit in left right terms so there is presumably other motivations at work.

I am bringing back ACT and United Future for this, as we have ratings for them, but still need to exclude Internet/Mana because of the whole ratings for both Internet and Mana confusing matters. So, the percentage of each party's voters that rated the party they voted for as closest to them (of the voters that rated all of the parties in the group, and answered the questions who they voted for, their self-rating, and the party best to deal with the most important issue in the country):

Party	% of voters closest	Sample size
National	74.26	571
ACT	66.67	3
Māori_Party	66.67	33
Labour	56.77	266
NZ_First	56.57	99
Green	56.11	180
Conservative	52.08	48
United_Future	0.00	4

There are some pretty big differences there (putting aside the handful of United Future zealots who voted from far along the spectrum). The concept of Left vs Right seems most important to National voters, then less important as you move left.

However, these results are strongly affected by how people space out the rating of parties. If you rate the Greens 3, Labour 4, and New Zealand First a 5, then to be closest to Labour you must rate yourself a 4 to be closest to the party. But if you rate National, the Conservatives, and ACT as 7 and New Zealand First as 5, any self-rating of 6 or better puts you closest to National (and ACT and the Conservatives). So these particular results, while interesting, shouldn't be read as too exact.

The party closeness can also be read in relation to the question that boils down to "what is the party you think is best suited to dealing with the most important issue facing New Zealand". We can consider if this was the party the person actually voted for (this is why I was including this question when making the previous graph).

Party	% voters think best	Sample size
National	88.44	571
Labour	61.28	266
Green	60.00	180
NZ_First	39.39	99
ACT	33.33	3
Conservative	22.92	48
Māori_Party	12.12	33
United_Future	0.00	4

The ability to deal with the most important issue seems to be broadly in line with party size (putting aside those with a handful of voters giving overemphasised weight to their opinions) and thus being able to have policies on stuff. But it is also broadly in line with electoral success (which is, after all, tied very much to party size).

If you look at both the left right spectrum and the best at dealing with issues in combination, if you explain people's behaviour with the left-right spectrum, then you also need to use best for issues, but If you use best for issues, that explains everything the left right spectrum does and more. So a minimalist explanation only needs to pay attention to issues.

Finally rather than comparing closeness and best party for the key issue as completely unrelated, we can work out for each party how many voters for the party were both closest and thought the party was best to deal with the key issue, how many were closest and thought it not best on issues, how many were not close and thought it best on issues, and how many were neither close to the party nor thought it best to deal with the key issue.

Of these final divisions the bestClose group who both see their chosen party as closest to them in left/right terms and feel that the party is best at dealing with the most important issue, I would imagine these people were very comfortable with their choice:

metric	Party_Vote	percent
bestClose	ACT	33.33
bestClose	Conservative	14.58
bestClose	Green	37.78
bestClose	Labour	36.09
bestClose	Māori_Party	6.06
bestClose	National	66.90
bestClose	NZ_First	26.26
bestClose	United_Future	0.00

The bestNotClose voters have reached across closer parties to vote for the party best able to deal with the most important issue, I'm thinking of these as issue voters:

metric	Party_Vote	percent
bestNotClose	ACT	0.00
bestNotClose	Conservative	8.33
bestNotClose	Green	22.22
bestNotClose	Labour	25.19
bestNotClose	Māori_Party	6.06
bestNotClose	National	21.54
bestNotClose	NZ_First	13.13
bestNotClose	United_Future	0.00

The closeNotBest voted for a party they see as close to them but this was not a party they thought best at dealing with a particular issue, I'm going to imagine these as being the voters of class interest.

metric	Party_Vote	percent
closeNotBest	ACT	33.33
closeNotBest	Conservative	37.50
closeNotBest	Green	18.33
closeNotBest	Labour	20.68
closeNotBest	Māori_Party	60.61
closeNotBest	National	7.36
closeNotBest	NZ_First	30.30
closeNotBest	United_Future	0.00

The notBestNotClose group are giving their support to a party not closest to them which they do not think is best at dealing with the most important issue, these are people whose voting reasons are not well represented by these questions.

metric	Party_Vote	percent
notBestNotClose	ACT	33.33
notBestNotClose	Conservative	39.58
notBestNotClose	Green	21.67
notBestNotClose	Labour	18.05
notBestNotClose	Māori_Party	27.27
notBestNotClose	National	4.20
notBestNotClose	NZ_First	30.30
notBestNotClose	United_Future	100.00

One possible reason is that these are representation voters- that people are voting to have the party in parliament even though the party does not specifically align to them or is the best to deal with issues. If that is the case, I think it is kind of heartening for democracy in a multiparty system.

I have moved the processing code (in R) into another document so that those that want to check the technical steps can do so.

45 responses to this post

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Tom Semmens, 14:10 Jul 28, 2016

So National party voters are more likely to launch spittle flecked ideolological tirades than Labour ones? You only have to read David Farrar or listen to Mike Hoskings to know one side is still fully engaged in the class war.

Sevilla, Espana • Since Nov 2006 • 2217 posts Report
David Hood, in reply to Tom Semmens, 14:46 Jul 28, 2016

So National party voters are more likely
Well, not really. There are a pretty big pool of National voters who, from these questions could be ideological or issues voters- we just don't know.
We do know there are a bunch of National voters who see themselves as a bit rightwing and National as more rightwing than they are. And Labour voters see themselves as closer to the centre than National voters.
You could argue the voters see the National Party (being more extreme) as more likely to engage in tirades than the Labour Party

Dunedin • Since May 2007 • 1445 posts Report
BenWilson, 16:29 Jul 28, 2016

Interesting stuff, David. Wish I had the time to go through my own findings on the last survey to compare and contrast. Are the questions mostly similar?
It was an interesting process last time. I think I found out a lot more about statistics than I did about NZ voters' opinions, though. I'd been hoping to find more interesting dimensions than left vs right, but of course the first PC axis accounted for most of variance that could be accounted for in the data (which it's designed to do), and that seemed to divide the issues along fairly predictable left-right lines. The second axis accounted for very little and didn't have much by way of recognizable pattern.
But then I realized that this was probably mostly because of the design of the questionnaire, which was massively full of left-right type questions, and had very few questions about, for example, environmentalism. Those that did exist were strongly correlated to votes for Greens, so I was left realizing that so much of what I was looking for was down to what questions get asked.
I'll be very interested to see what else you find in this survey. The finding that there is a left-right ordering of our parties seems to be unchanged. National is still at the far right of the parties with meaningful numbers. What else are you thinking of looking at?

Auckland • Since Nov 2006 • 10657 posts Report
David Hood, in reply to BenWilson, 19:12 Jul 28, 2016

Ben, you might get a sense I have my doubts that the Left-Right umbrella terms have any more use than "I am voting National so I must be on the right but I feel like they are a bit more extreme than me" rather than as a determinant. It is just, as you said there are a lot of questions that place things in that context.
Similar survey, with some potential of linking results over time (he said nodding towards the future) a mix of general political questions, demographics, and questions about issues around election time.

Dunedin • Since May 2007 • 1445 posts Report
David Haywood, 19:25 Jul 28, 2016

Very interesting indeed, David! Thank you for all your hard work in investigating this for us.

Dunsandel • Since Nov 2006 • 1156 posts Report
Ian Dalziel, in reply to Tom Semmens, 08:44 Jul 29, 2016

tirade unionists...
spittle flecked
Ahh, welcome to the sleepy little hamlet of Spittlefleck, where village idiots outnumber the rest. More colic than bucolic, and the smouldering resentments are abiding proof that it takes a 'child' to raze a village

Christchurch • Since Dec 2006 • 7953 posts Report
BenWilson, in reply to David Hood, 14:12 Jul 29, 2016

It's kind of interesting that if you ask the right questions, then the left to right scale does seem to form the most important principal component axis, and the parties do seem to order themselves according to the self-rated left/rightness of the respondents. I don't know if that shows more than a vague consensus on what these terms actually mean, though.
I wasn't able to model that much of an improvement in accuracy based on political opinions than the null model (which is that everyone votes National). That would be 42% right, and the best prediction model using random forests and taking hundreds of opinions into account got that up to 57% (crossvalidated). So maybe a 15% improvement in ability to guess how someone votes was attained off the answers to 74 questions.
Not sure what to make of that. Either the wrong questions were being asked (obviously I eliminated questions like "which party did you vote for" and "which party are you most sympathetic to"), or political opinion (divorced from specific knowledge of their opinion on particular parties) accounts for very little of the way people actually vote. Or a bit of both.
There was me hoping to build a 10 question tree that could ascertain who you were going to vote for without ever mentioning a party name (or a proxy for it, like "the government"). But no.
It's not like this is the terrible fault of people not knowing what they want. I think it's much more of a factor of the parties being broad churches that very significantly claim to offer much the same things. The weak signal is not in what people want, it's in which party will give that to them. But this is speculation on my part. Can't prove any of that.

Auckland • Since Nov 2006 • 10657 posts Report
linger, in reply to BenWilson, 15:25 Jul 29, 2016

Part of the difficulty in attempting to build a general model for voting choices may be that often the same label (e.g. “business-friendly”) will have different meanings and evaluations to voters for different parties.
e.g. National basically owns the label “business-friendly”. However hard Labour tries to market itself on that basis too, it doesn’t work for them: even though both National and Labour voters may be generally in favour of government supporting businesses, National voters believe National is more business-friendly than Labour, and only existing Labour voters believe Labour is actually business-friendly. (Meanwhile, Green voters may interpret “business-friendliness” in rather different terms, either evaluating it with much lower priority – if not actually negatively – or else equating it with, say, promoting efficiency and sustainability in business.)
Result in this case: there are probably strong entrenched differences in opinion, but a question about, say, “importance of looking after businesses” probably won’t identify any strong connection to voting patterns, except through evaluations of named parties.

Tokyo • Since Apr 2007 • 1944 posts Report
linger, in reply to BenWilson, 15:32 Jul 29, 2016

Probably questions measuring priorities placed on different issues would be more successful predictors of voting preference than questions measuring reactions to single issues?

Tokyo • Since Apr 2007 • 1944 posts Report
BenWilson, in reply to linger, 16:31 Jul 29, 2016

Yes, the NZES was not built for the purpose I was using it, so it's not that surprising it wasn't that fit for it. Still a very interesting resource though, there's nothing else like it in NZ.

Auckland • Since Nov 2006 • 10657 posts Report
BenWilson, in reply to linger, 16:44 Jul 29, 2016

I'd say prioritizing is a big part of what we do when making decisions. I'd go further, though, to say that most people probably essentialize their thinking, homing in on a small group of issues that they think matter. But these are different for everyone, and even if the same, who they believe will sort out these issues can be very different. It's also very hard to tell whether someone claims a particular issue is the most important thing, but is actually making their decision based on factors they can't admit - possibly not even to themselves. I'd say racist factors are like this.
In short, prediction of humans is hard! Even if they actually tell you who they would vote for, that's not 100% accurate.
That was what was really interesting to me, that despite a far richer set of questions, the ability to guess who they would vote for wasn't a great deal better than just asking them if they are left or right wing.
I never looked into the influence of demographic factors. It's an interesting question. I bet it's highly collinear in many instances to opinion, so the predictive effects would not stack. But I'm guessing.

Auckland • Since Nov 2006 • 10657 posts Report
David Hood, 18:33 Jul 29, 2016

There are both a series of questions rating the importance of a standard issues from the last election, and a free text "what is the most important issue to you" kind of question where people could write whatever they feel (which has also been coded into general and specific subject categories).
Because I'm curious, this evening I'll take the free text and figure out the commonest words written by party voted for.

Dunedin • Since May 2007 • 1445 posts Report
David Hood, 19:38 Jul 29, 2016

I haven't done any stemming (removing suffixes to bring terms together), but here are the commonest 10 terms written by NZES in the most serious issue free text question (removing common stop words like a, the, not, etc) for words that come up at least three times, assuming there are 10 terms that crop up at least 10 times. As I did nothing about sorting out ties, the tail end of each list may be a bit arbitrary as they could be tied with things that made the number more than 10.
Conservative: economy, government, know, housing, issues, land, no, cost, education, employment
Green: poverty, environment, child, education, rich, between, poor, inequality, gap, economy
Internet_Mana_Party: poverty, housing, child, no, children, feeding, schools
Labour: poverty, housing, health, nz, education, between, rich, child, assets, gap
Māori_Party: economy, health, poverty, employment, selling, education, economic, nz, our, education
National: economy, economic, stability, nz, housing, poverty, stable, dirty, education, politics
NZ_First: selling, economy, nz, housing, people, land, employment, overseas, tax, poverty
Didn’t Vote: poverty, economy, nz, dirty, politics, housing, health, jobs, know, child
ACT and United Future had insufficient representation to have any words occur 3 times or more.

Dunedin • Since May 2007 • 1445 posts Report
BenWilson, in reply to David Hood, 19:59 Jul 29, 2016

There are both a series of questions rating the importance of a standard issues from the last election
Yes, although rating and ranking are not the same thing. Not that either is clearly superior, but I do think that ranking is a pretty normal mental process when faced with massive numbers of issues. I don't know how many people genuinely make decisions by aggregating hundreds of ratings of, say, parties performance on policies, and then impartially looking at the highest score and choosing the party that matches. I'd say that they mostly choose first and then crystallize their decision down to what small subset of questions matter most to them and claim the decision boils down to that. Which it might even have done, at a subconscious level. Maybe there was some wavering over the critical issue, if more than one of the parties credibly contested it in their minds.
, and a free text “what is the most important issue to you” kind of question where people could write whatever they feel (which has also been coded into general and specific subject categories).
Which is very important. But suffers from having so many possibilities and many interpretations, such that it might be hard to get robust numbers except for the large parties and most common platitudes.

Auckland • Since Nov 2006 • 10657 posts Report
BenWilson, in reply to David Hood, 21:29 Jul 29, 2016

Love it. "Dirty", a reason to vote National, or not at all!

Auckland • Since Nov 2006 • 10657 posts Report
David Hood, 22:07 Jul 29, 2016

I should really link up Dirty Politics and Don't Know to be single terms- don't was on my list of excluded terms, hence Conservatives were in the know, rather than don't know

Dunedin • Since May 2007 • 1445 posts Report
David Hood, 21:33 Jul 30, 2016

I did a better way of looking at it: rather than absolute amounts this is how often voter groups are (+) or are not(-) using terms relative to other voter groups use of those terms. The more terms beside each party, the more that part had unusual terms frequencies (I took the most unusual 100 and aggregated them by party). For each party the terms are in decreasing order of unusualness
Conservative:-poverty, +economy, -health, +government, +land, -child, -jobs, +justice, +moral, +leaders, +law, +management, +don't_know, +financial, +cost, +issues, -economic
Green:+poverty, +environment, -economy, +rich, +between, +inequality, +child, +poor, +gap, -selling, +climate, +change, -employment, -health
Internet_Mana_Party:-economy, +schools, +feeding, +wages, +children, +poverty, +sales, +marijuana, +support, +tppa, +assets, +low, -education, +issue, +important, +income, +child, -health, -land, -dirty_politics, +housing
Labour:-economy, +poverty, +between, +rich, +health, +poor, +gap, +inequality, +wage, +assets
Māori_Party:+health, +education, +economy, +employment, +selling, +whanau, +economic, +settlements, +economics, -issues, +growing, +leadership, +cost, +poverty, -rich, +lack, -government, +families
National:+economy, -poverty, +stability, +economic, -employment, -selling, +stable, +keeping, -poor, -assets
Did_Not_Vote:-economy, -poverty, +follow
NZ_First:+selling, -poverty, +people, +immigration, -economy, +overseas, +land
Focusing on things common to all groups, there is a pretty clear division, that comes out of the data between:
(poverty discussed, economy not discussed) parties, and (economy discussed, poverty not discussed) parties
With the two parties that thought of themselves in the middle (NZ First) and the Māori Party forming their own opposing
(poverty discussed, economy discussed) Maori party and
(economy not discussed, poverty not discussed) NZ First and Did Not Vote
Many of the parties can then be seen to have their specialist themes by their supporters, as well as common ground.

Dunedin • Since May 2007 • 1445 posts Report
BenWilson, 19:33 Jul 31, 2016

So the + or - is whether the term occurs more or less proportionately per group than the mean proportion across all groups? So if "economy" occurs in, say, 50% of responses, but in 51% of National voter responses, then it's a +? Just trying to get my head around what you're doing there.

Auckland • Since Nov 2006 • 10657 posts Report
David Hood, in reply to BenWilson, 21:11 Jul 31, 2016

Following the term economy through:
I get the number of mentions of every term for every party. This gives the raw number of mentions of every term, for all of the parties tested.
Then I generate the percentages for each term for each party, dividing the raw number by the total number of terms for each party (which normalises for the number of terms). Effectively getting the proportion of each term among the parties terms.
Then I calculate the mean proportion for each term (this is not usage of people, this is the mean of occurrences between party voter groups).
Then I subtract the mean from each term for each party, to get how far from "typical" each parties frequency of the term is.
Then I rank all the terms in order from most atypical to least atypical (closest to the mean) and take the 100 most atypical.
Then I reorganise them into a list for each party.
Because economy is a very polarised term (parties voters either used it a lot or not at all), there was no party that was near the mean in its usage, so it showed up in all the parties. Similarly poverty, but the usage was in the opposite direction. + for unusually high usage, - for unusually low usage. So while you are correct in the sign, it is based on being the largest differences among all terms in the data.
Then we've got terms like moral for Conservatives or environment for Greens where the term was used enough to put it in the overall 100 most extreme terms, but other parties usage of the terms was closer to the mean so did not make the shortlist for anyone else.
I've put the R code up that I used if it helps- but it wasn't written for an audience, it was just something I whipped up quickly and may be a bit dense in places.
https://github.com/thoughtfulbloke/politcalTerms

Dunedin • Since May 2007 • 1445 posts Report
BenWilson, 10:32 Aug 1, 2016

OK, I think I get that. So you would get a -economy for a group if, for example, economy was not one of the terms mentioned at all for that group, putting it well below the mean?
It’s idiosyncratic but I think I get what you’re trying to do. Kind of like an ANOVA, looking for significant differences (in spirit, obviously, not in the detail)?

Auckland • Since Nov 2006 • 10657 posts Report
David Hood, in reply to BenWilson, 10:55 Aug 1, 2016

So you would get a -economy for a group if, for example, economy was not one of the terms mentioned at all for that group, putting it well below the mean?
Correct, assuming that the mean was not just above zero (one group using it and all the rest not doing so would be a case like moral for the Conservatives, where the mean is near zero so it shows up for no-one else).
You could look at it as inspired by ANOVA- I would probably view it as a cross between a text analysis term document matrix and outlier detection, but I will (idiosyncratically as you say) draw on what musical instruments inspire when writing a data analysis song.

Dunedin • Since May 2007 • 1445 posts Report
linger, in reply to David Hood, 13:07 Aug 1, 2016

What came to mind for me is Yule’s Q = (a – b) / (a + b) which has been used to compare relative word frequency (i.e., word counts normalised for text length) in two language samples (with respective relative frequencies a, b per million words). What you’re doing seems to be an extension of that approach to multiple samples.

Tokyo • Since Apr 2007 • 1944 posts Report
David Hood, 14:53 Aug 1, 2016

So that is the change from a to b as a proportion of the combined proportions? Similar I suspect, but I used an aggregate figure for b to given a common baseline to compare multiple entries, and didn't divide. I imagine the not dividing has the effect that big difference between big proportions matter more than little differences between little proportions, but I am comfortable with that in the story this data is telling.
I thought this evening I might run a principle components analysis on the terms frequencies and see what kinds of party clustering it shows up. I think the left/right axis Ben found in the previous election results from the survey generally looks like it is mirrored in the economy/poverty axis (which are inverses of each other except in the middle).

Dunedin • Since May 2007 • 1445 posts Report
David Hood, 19:28 Aug 1, 2016

A basic PCA of the entire data is essentially useless. PCA1 puts National way off by itself with everyone else clumped, PC2 puts Labour off by itself, PC3 puts the Greens off. My working theory is that as National got the most votes/representation in the survey it has the most unique vocabulary for identifying it as different, but this is a function of sample size (and vocabulary richness I suppose) rather than inherent differences.
I am going to play around with it experimenting/inventing approaches as my hunch is there is something interesting in here.

Dunedin • Since May 2007 • 1445 posts Report
linger, in reply to David Hood, 20:00 Aug 1, 2016

Yes, pretty much.
Yule's Q is a dimensionless ratio that varies between -1 and +1:
terms with Q=-1 are associated only with sample B
(a=0, hence (a-b)=-b, (a+b)=b, hence Q = -b/b = -1);
those with Q=+1 only with sample A
(b=0, hence (a-b)=a, (a+b)=a, hence Q= a/a = +1);
Q=0 corresponds to no difference (a=b, hence (a-b) = 0).

Tokyo • Since Apr 2007 • 1944 posts Report