Saturday, October 7, 2017

Labour lost votes to National in electorates with the highest proportion of Asian and African immigrant voters

Labour campaigned on cutting immigration by 20,000 to 30,000 people every year. Labour’s subsequent 10% vote boost across general electorates was tempered by a less enthusiastic boost from electorates with many residents from Asia1, and in those electorates, National actually gained overall. Overall there is currently no significant link between an electorate’s Asian immigrant population and that electorate’s level of support for Labour. But the change from 2014 to 2017 is significant: for every 1,000 residents from Asia in an electorate, National’s vote went up by 0.25% while Labour’s went down by 0.28% over the three-year period marked by a series of public statements and policies by Labour widely perceived to be anti-immigrant and anti-Chinese. Labour may risk alienating kiwi voters from Asia further in the future if they continue down the same path from now until the next election.

Labour campaigned against immigration in the last election and there has been speculation that their anti-immigrant stance hurt Labour in the Asian immigrant vote. Some data has come out suggesting widespread support for the National Party from Chinese voters.

I can’t directly test immigrant support for Labour, but I can test the support for Labour in each electorate and compare that to the proportion of immigrants in that electorate.

Statistics New Zealand provide easily accessible information on ethnic groups and world birthplace in each electorate. Unfortunately, neither dataset allows us to drill down to distinguish between different Asian countries or cultures, for instance, to look at relationships to Chinese or Indian residents in particular. Because we’re interested in immigration, I used the data on birthplace rather than ethnicity. So every time I talk about “Asian immigrant residents” or “residents from Asia” in an electorate here, we’re looking at the number of people born in Asia (excluding the Middle East) who were in that electorate on Census Night 2013.

Considering the effect of Greens support doesn’t change the result


It is possible the difference change we can see here arose from other factors. Urban and student areas feature prominently in the regions with the largest changes, so perhaps the change is driven mainly by students. Of those regions, only Auckland Central has a particularly high share of residents from Asia. There is evidence that whiter urban liberal electorates were the largest contributor to Labour’s success, maybe at the Greens’ expense. We can estimate their effect by using the Greens’ success in each electorate in 2014 to predict Labour’s success in 2017.

Adding Greens’ success in 2014 as a predictor only makes the effect of Asian immigrant residents in an electorate even more important. We can calculate that on average, for every 950 votes the Green party got in an electorate in 2014, we’d predict that electorate to have a 1% rise in Labour support from 2014 to 2017. Using the same method, we predict that for every 3600 Asian immigrant residents in an electorate, there is a 1% fall in Labour support, or, more accurately, 1% less of an increase from 2014 to 2017.

Labour’s loss was National’s gain


It might also be interesting to see how National did:



This is actually instructive, too. It turns out that there’s a very strong relationship between National support and Asian residents in an electorate. For every 4000 Asian residents in an electorate, there is a 1% rise in National support.

Results were similar for electorates with high immigrant populations from the Pacific Islands and Africa…but not the UK


We can compare these patterns to correlations between change in Labour support and immigrants in electorates from other regions.





Electorates with high numbers of immigrants from Pacific Island and Middle East and Africa sources followed the same significant trend as those with high numbers of immigrants from Asia. We actually saw the reverse pattern for electorates with high numbers of immigrants from the UK and Ireland: a larger swing towards Labour.

What does this mean?


There’s been speculation that Labour’s immigration policies may have influenced voting in 2017, particularly by influencing people in electorates with high proportions of residents from Asia. The data suggests that in electorates with more people from Asia, the Pacific, or the Middle East and Africa, Labour did not gain nearly as much support as in electorates with relatively few immigrants from those regions.

This might be relevant when Labour works to frame immigration policy. When voters have themselves immigrated to New Zealand; when their neighbors have; they may have more sympathy for immigrants and question restrictive immigration policies.

Following through on a campaign promise to reduce immigration by up to 30,000 people every year would be a huge change and the data I presented here could mean that it would harm Labour in the polls three years from now. National has resisted making similar changes, and Bill English actually claimed Labour’s changes would end up having minimal effect on long-term migration, because the changes mostly target international students, 80% of whom return to their country of origin. In any case, if Labour wants to avoid high-immigrant electorates becoming characteristically National territory, they may need to reach out to those communities to find out what might be alienating them from voting Labour.


  1. Here, “number of residents from Asia in an electorate” means the number of people in the electorate on Census night 2013 who reported being born in an Asian country. See 2013 Census electorate tables.

Saturday, July 8, 2017

"Kill All Normies: Online culture wars from 4chan and tumblr to Trump and the Alt-right"


Kill all Normies paints a picture of the modern world (the “post-post-modern” world might be more appropriate) as a online-bleeding-to-offline battle between transgressive and post-modern forces rooted in Tumblr ‘social justice’ blogs on the one side, and 4chan and various subreddits on the other. The author, Angela Nagle, calls on the left to abandon what she describes as the “transgressive style” for kind of more affirmative politics. She says that since the 1960s, the left-liberal style, which the left has carried with it throughout its takeover of academia, the media, and other cultural centers, has been appropriated by the right. In her reading, there’s nothing inherently leftist about the ‘transgressive style’. Such shock-and-awe can be used to destroy conservative norms and values, as it did when a figure of crucified Christ was submerged in piss and displayed in a New York art gallery, or perhaps more constructively, from the 1960s sexual liberation movement through to today’s broader struggle for rights for gender and sexual minorities. But the transgressive style can be also used to destroy mainstream taboos against sexism, racism, and generally just not being horrible to people in public. Recently disgraced figure Milo Yiannopoulos might be the most famous example yet. He described his role as a “provocateur” (basically a troll but offline, I guess?) and spent months touring around campuses in the US goading liberals into hysterical and violent responses to his transphobic and anti-feminist rhetoric.


Nagle’s response is to call for the left to end its fascination with the “transgressive style”, and to find a new rhetorical aesthetic. The left has not always been about tearing down convention for the sake of it, and perhaps we have some conventions which are worth defending.


But how much does all this matter? Are the obscure corners of Tumblr with their 50 genders and otherkin really influencing wider culture? Or is /r/The_Donald and the rest of the Alt-Right - Richard Spencer, et al. - really responsible for getting Trump elected? Or are they an irrelevant freak-show whose influence and voice are amplified by the media to drive ratings and exaggerated by activists on the other end of the spectrum to validate the necessity of their own cause? I’m sure Trump had his support from the subreddit /r/The_Donald and associated young white and male supporters. But did /r/The_Donald and associated Alt-right and fascist-sympathizing online movements really get the Donald elected?


This is important because if the online culture wars really are shaping the wider discourse, it is possible their influence will grow and it is important to pay attention to them if you want to know where the culture is going and what direction politics is likely to take in the future. On the other hand, if these fringe online movements are mostly just extremes of wider culture, all the media’s attention on them may be unhelpful and even serve to exaggerate support for Donald Trump and the extent of extreme views on both the left and right.


To me it seems like new right-wing media - InfoWars, Breitbart News, etc., played a part. Facebook has also been accused of playing a part by enabling “Fake News” producers to spread untrue findings, like for instance, an infamous story about the Pope endorsing Donald Trump. Both of these forces are obviously a recent phenomenon and you can chalk them up to online movements, but I am not sure how linked they are to grassroots culture movements by young right-wing activists and trolls on 4chan.


On the flipside, I think progressive movements have succeeded in culture change in particular instances, for better and, following backlash, for worse. Black Lives Matter have been very active and have succeeded in getting their concerns into the mainstream. There has been a response by the media and police to try to address their concerns. Though we are not there yet in achieving the goals set out by BLM, they’ve made their concerns known. Activists for transgender rights have succeeded in having transgender rights issues pushed into the public consciousness, although even there it sometimes seems like the backlash has been stronger than the initial movement. In spite of all this, I am not sure these movements really played such a large role in the election. Surely it was the Democratic establishment, not accusations of sexism and racism by “Bernie Bros” and “brosocialists”, that made Hillary’s win?

In general I enjoyed Angela Nagle’s call for a more affirmative politics, less focused on the ‘politics of transgression’; a progressive liberal politic more focused on building than tearing down - abandon irony to the twitter trolls. The right has always focused on the “rhetoric of fear” to the liberal’s “audacity of hope” so perhaps this is not entirely new. But appeals to emotion and group interests are very human and I’m not sure you can just change the political game by refusing to be drawn into them.

Monday, January 4, 2016

Social trust: which direction is the causal relationship with socio-economic status?

Social trust is important to the cohesiveness of a community. Empirically, people with high levels of social trust tend to be doing pretty well for themselves, which raises the question: does a lack of social trust keep people poor, or is it that being rich people helps people to trust others around them more? This is the question in the December 2015 article published in Political Psychology titled "Changes in Income Predict Change in Social Trust: A Longitudinal Analysis", by Mark Brandt, Geoffrey Wetherell, and P. J. Henry.

Some researchers think that people with low social status tend to adopt a more defensive mindset due to constant threats to their self-worth arising from their low social status. African Americans who expect to be rejected because of their race experience distrust other people more than African Americans without that expectation. Conversely, rich people have trustworthy social networks to rely on, obviously have had good social experiences in the past that led to their presently having a lot of money, and also have the financial resources to fall back on if they take some kind of social risk and fail.

On the other hand, although trusting is risky, in the long run in prisoners dilemmas games it’s a good strategy. Authors said that people with more social trust are more likely to build social capital, citing a study that suggested the exact reverse, that civic participation leads to interpersonal trust rather than the other way around (Brehm & Rahn, 1997). So maybe they have less prior evidence for the “higher trust causes higher status” hypothesis than they thought. The authors look at longitudinal data from the US and the UK to try to see lagged changes over time. They’re doing something strange with the data in calculating the average of two different measures that they say have different effects. 

They could have tested whether income at T1 is correlated with social trust at T2. Instead, they looked at whether the change in income from T1 to T2 predicted the the change in social trust from T2 to T3. In the US sample, they found an effect of an increase in income between 2000 to 2002 to on increase in social trust between 2002 or 2004. Seems there is a lot that could cause this kind of increase. In the British sample there was an effect, when covariates were not controlled for, but it wasn’t strong. However there was a consistent lack of any sign of a pathway from social trust to income, which makes for a nice contrast.


The effects don’t seem incredibly compelling and the authors could have dug down more with the covariates to see which if any mediated the social trust relationships. But if we overlooked this, it seems like their results show an effect of income on social trust, which is similar to the first of two hypotheses described and the only one for which they seem to have found prior research supporting.

The authors acknowledge that limitations of the design, though not the limitations of the effect size or level of significance. 

Wednesday, May 13, 2015

Mainline churches lose more members than evangelicals and Catholics, while Catholics gain very few new believers

The new Pew survey on religion in the United States found America's unaffiliated population boomed from 16 to 23% between 2007 and 2014; the Catholic population declined from 24% to 21% and Mainline Protestants declined from 18% to 15% of the population. In contrast, evangelicals almost held steady, going from 26% to 25%, and historically Black churches, whose members generally identify as evangelical, also held steady at 7%.

Pew writes:

"While the mainline Protestant share of the population is significantly smaller today than it was in 2007, the evangelical Protestant share of the population has remained comparatively stable...As a result, evangelicals now constitute a clear majority (55%) of all U.S. Protestants."

So why are Evangelicals holding steady? I can think of two explanations:
  1. Evangelicalism is more distinct from being unaffiliated; there are higher barriers to moving in and out of evangelicalism and so people are less likely to leave. The fact it's a form of Christianity that generally holds its members to stricter, more traditional standards than, at least, mainline churches, could bolster their sense of belonging and its distinctive value from being unaffiliated. Looking at mainline churches, they might ask, "If your church doesn't require anything special or distinctive from Christians, what's the point?"
  2. Evangelicals lose as many members as Catholics and Mainlines, but they make up for it by gaining members, too. So, Evangelicalism's stricter standards don't seem to be holding members in; but on the other hand, evangelical churches do seem to be more capable of attracting new members to make up for the members that they along with the other churches are losing.
We can look at Pew's numbers; they published the following table:


At first glance it looks like the second explanation might be more plausible. 10% of all US adults weren't raised evangelicals, but joined an Evangelical church at some point, while 9% left an evangelical church having been raised evangelical. In contrast, mainline and Catholic churches lost even more adherents but more strikingly, only gained 2% and 6% of members between them.



But perhaps a better way to characterize each of these religious groups and how they relate to members is to measure who leaves and joins as a proportion of the church group rather than as a proportion of US adults. Fortunately that's just a little bit of simple math. Rearranging the figures on the above table, we get:




Here, the numbers change a little. Evangelical churches are similar to Catholic churches in that they've both lost around 40% of their members to other groups. Both church groups are losing fewer members than mainline churches, who lost almost 60% of the proportion of people raised in mainline churches. But evangelical churches are similar to mainline churches in that both groups pick up quite a few members from other traditions, unlike the Catholic church, which picks up very few new members. Evangelicals' combination of gaining quite a few new members and losing quite a few contrasts with mainline churches, who gain members but lose even more, and Catholic churches, which lose as many as the others and gain very few.

How does this reflect on the groups? The Catholic church seem unattractive to outsiders, either because they don't actively work so hard to convert others, have high entry barriers, or are just not appealing to people raised in other groups. Mainline churches are reasonably attractive to outsiders (more than half of whom are coming from evangelical or Catholic churches rather than unaffiliated) but lose over half of the members raised in their groups. Evangelical churches have both a moderate level of joining (principally from the other churches, not from people raised without religion) but also lose a moderate number of believers to other groups. As a whole, it seems around half of people leaving various Christian groups are not joining other Christian groups, though we can't tell from these numbers which Christian groups tend to go unaffiliated rather than to other Christian groups.

So, in summary, relative to mainline churches, it seems like conjecture (1) above is true of Evangelicals: people are less likely to leave the Evangelical church than mainline churches. But relative to the Catholic Church, (2) is truer: people do leave, but many more people join the Evangelical church compared to the Catholic Church, suggesting Evangelicalism is not better at holding on to members than the Catholic church, but is especially good at attracting new ones.

All that said, the most striking image from the graphs is the change of the unaffiliated groups. About 40% of people who are raised without religion tend to join one, a similar proportion of people who are raised evangelical or Catholic who change their affiliation. But simply because so few people were raised without religion, the proportion of people who are religiously unaffiliated now but were raised Christian is very high. Of people who aren't members of a religious group, across the ones who weren't raised in a religion and those who were, more were atheists or agnostics, and fewer said religion was even somewhat important to them.

Saturday, February 7, 2015

How straight people react to photos of straight, gay, and lesbian couples


  • Straight people rate photos of straight couples more highly than gay or lesbian couples
  • Researchers found neural markers that probably influenced the ratings
  • The ratings were strongly connected to the raters' general Attitudes Toward Lesbians and Gay Men
  • Spending time with gay and lesbian people seemed to positively influence the ratings they have the gay and lesbian photos
  • What does it mean?
The gay rights movement has made huge strides in the last couple of decades. Here in the United States, state after state are currently removing prohibitions on legal recognition of same-sex marriages. Yet as of the time of publication, many states still prohibit same-sex marriage. If attitudes toward racial minorities is anything to go by, even after formal discrimination in law is removed, other forms of discrimination are likely to linger on.


"Social categorization" is the term social psychologists use to describe humans percieving each other as members of social groups rather than as individuals. It's a very natural and human thing to do. Without some kind of social categorization, we would know a lot less about anyone we haven't met and got to know personally and it would be much more difficult to interact with strangers! But it's clear that this process also underpins prejudices and therefore discrimination against disadvantaged minority groups.
Cheryl Dictker, Catherine Forestell, and Blakely Mulder at the College of William and Mary took at look at how heterosexuals responded differently to pictures of gay and lesbian couples, compared to pictures of straight couples. This would give them a way to measure biases that heterosexuals might have against gay and lesbian couples.


The researchers found some pretty definitive differences (Figure 1) in the way their heterosexual research participants behaved. They asked their participants to rate each picture they saw, and dismiss each photo to move on to the next when they'd made a judgment. You might expect that in today's society, people would want to avoid appearing prejudiced by giving a lower rating to gay and lesbian couples than straight couples. On the other hand, because participants were rating each individual couple photo independently, they mightn't have been able to make the right adjustments to compensate from automatic prejudice even if they were trying. In any event, participants rated gay couples as well as lesbian couples significantly lower than straight couples, and they also dismissed photos of gay couples faster than straight couples. Incidentally, women may have rated the gay couples even lower than men did. These ratings didn't seem to be just accidents related to the photos either. Participants took an Attitudes Toward Lesbians and Gay Men survey, and the lower their attitude was, the more negatively they rated the gay and lesbian couple photos.

Figure 1, from the article: "Reaction times to dismiss (top panel) and explicit ratings of (bottom panel) pictures of gay, lesbian, and straight couples. Error bars represent standard error of the mean."

The researchers also measured electrical activity in the brain (Figure 2). They examined signals known to appear when people view racial "out-groups", called "N1" and "P2" signals, and a signal that has been associated with negative judgments, the "LPP" signal. Participants had the "out-group" P2 reaction for gay couples more than straight couples1, and they also had the LPP 'negative judgment' signal more with gay and lesbian couples compared to straight couples.

Figure 2, from the article: "ERP amplitudes in response to pictures of straight, gay, and lesbian couples." The top image shows the "Fz" location with the N1 and N2 measurements highlighted, and the bottom image shows the "Pz" location with the P2 and LPP measurements highlighted.



The good news is that the more social contact with gay people participants said they had, and the more genuinely personal contact they had, the smaller the differences between ratings for straight couples and ratings for gay/lesbian couples were. There were some relationships between the electrical signals the researchers were tracking (N1 and P2 signals) and the proportion of GLBT friends and experiences with GLBT friends subjects had, although they weren't strong relationships and their statistical significance is questionable given the number of non-significant relationships. All might mean that as gay and lesbian couples become more visible in society, the bias against them will disappear, or at least decline. It's hard to know this for sure, though: do people with more positive attitudes towards gay and lesbian couples spend more time around them, or does spending more time around gay and lesbian people lead to the more positive attitudes?

It's notable that the clearest results from this study weren't from measuring electrical activity in the brain; they were from the ratings participants gave themselves, and from their reaction times. In particular, although there were some statistically significant correlations between electrical signals and the amount of social interaction with gay and lesbian people, they were weak and we probably couldn't draw any conclusions from them if the photo ratings hadn't indicated the same things so clearly. Additionally, of all the neural signals the researchers examined, only the LPP signal is clearly associated with negative judgments. The others tell us that participants thought the gay and lesbian couples were out of the ordinary, but not necessarily in a bad way. That's a good reminder that although neuroscience tools can be useful, the hype in the media might be out of proportion to their usefulness.

If this all sounds a bit depressing, we might also consider that people are capable of adjusting their implicit biases during overt actions. These tests are designed to see past those actions. For a society without prejudice, ideally no-one would have any unfair biases, implicit or explicit. But it also seems natural that straight people might relate better to photos of straight couples than gay or lesbian couples. As far as prejudice goes, we might get a long way simply asking people to be aware of their own biases and be willing to adjust for them. Studies like this remind us that, at least at present, the biases exist, and so it's important we consider how that might affect how people are treated.



1 The difference between lesbian couples and straight couples was in the same direction, but not statistically significant (p=0.10). Taken with the difference between gay couples and straight couples, it's probably reasonable to infer that with more participants, the researchers would have seen a result with lesbian couples, too.

Saturday, December 20, 2014

Black voters - especially conservatives - assume Black candidates share their political ideology

Voting is a notoriously fickle activity. And why wouldn't it be? Each voter gets only a tiny fraction of a percentage of a say in who their electoral representative will be and so it is unsurprising many voters will make a more automatic, intuitive judgment on their vote rather than through careful and time-consuming consideration of the costs and benefits to them or to the people at large.

Often we vote for people we think look like ourselves or seem like ourselves. When Mitt Romney, a Mormon, ran for president, evangelicals and atheists worried about whether he'd be suitable, while George Bush, an evangelical, drew his support from the evangelical community. Voters prefer an 'everyman' candidate who they can relate to – imagine having a beer with – to a candidate they might concede as more intelligent, but could seem out of touch. All of this might be completely rational – who better to represent your voice than a representative who thinks like you? Black Americans flocked to support President Barack Obama over his opponents – their support was essential, in fact, to getting him and keeping him in the White House. Only 39% of White Americans voted for Obama in 2012, compared to 93% of African Americans.

Berkeley researchers Amy Lerman and Meredith Sadin set out to understand why African Americans in particular have such a strong preference for African American candidates. It has been argued that Black voters prefer to give up being represented by someone who thinks like them in order to get a representative who looks like them. Lerman & Sadin wondered if that was accurate. Black voters considering a Black candidate see an in-group member; White voters, at least racially, see an out-group member. Group identities are important for everyone, and everyone sometimes uses stereotypes to judge others by group membership, in-group or not. This is especially true if we're making an automatic, intuitive decision as in the way many of us make up our minds about voting.

The researchers predicted several findings related to stereotyping Black candidates:
  1. White voters will stereotype a Black candidate as being more liberal than an identical White candidate, because of racist stereotypes about Black people or simply because they use a statistical probability heuristic.
  2. Black voters have a stronger racial identity than White voters, both because they are a numerical minority and because they're a particularly oppressed minority – more so than other racial minorities in America. Because of this, they'll project their own beliefs onto candidates more than both Whites and other racial minorities.
  3. Because statistically, Black candidates tend to be more liberal, Black conservatives will experience greater cognitive dissonance between wanting a candidate who represents their views, and one who looks like them. To cope with that, Black conservatives will use projection more than Black liberals.
  4. The degree to which a voter projects their views on a candidate predicts their likelihood of voting for that candidate.
The authors described a hypothetical candidate to over 3000 people. The description included a picture of the candidate, either as a Black or a White person. There were Black and White people who judged the candidates based on their race, but they tended to make those judgments in different ways.

In the sample of 3000 people with hypothetical candidates, Black people tended to judge the Black candidate as 'like them' ideologically. Black conservatives thought the Black candidate was more conservative then the White candidate, while Black liberal didn't significantly draw strong conclusions about the candidate from the candidate's race. In a subsequent analysis of the American National Election Survey, White Americans tended to stereotype their Black representatives as much more liberal than White representatives. Black Americans showed similar patterns to the sample of Black participants in the study sample. Going back to the question of what Black voters do when choosing between voting for a candidate who looks like them or a candidate with their political ideology, it seems like Black voters have their cake and eat it too: they tend to assume the candidate who looks like them has their ideology.

White conservatives judged White representatives as more conservative than they judged Black representatives.
White liberals stereotyped White candidates as more conservative than Black candidates.
Black conservatives thought Black candidates were more conservative, preferred them, and were more likely to vote for them.
Evidence unclear, but Black liberals perhaps more likely to vote for a Black candidate

While Black voters might not prefer a Black candidate simply because they share skin color, they do perceive Black candidates as more ideologically similar to them and are more likely to vote for the Black candidate compared to a White candidate. This was most true for Black conservatives. If this holds out in the future and in the population at large, it might imply that Black candidates, particularly liberal Black candidates, can take advantage of support from Black voters regardless of whether their ideology matches up with the people they represent.

In follow-up studies, the authors applied their analysis to Latinos – but for whatever reason, the effects they saw in the Black population didn't transfer to the Latino grouping. A lot of Latinos self-identify as White and the grouping may be less cohesive than the Black racial grouping. So whether the results apply to minorities in New Zealand like Maori, Pacific or Asian ethnic groups could be the subject of future research.

Sunday, September 28, 2014

Low voter turnout, a landslide for National, and a lack of good alternatives are probably all linked

77% of New Zealanders turned out for our recent election. In many countries, 77% would be an awesome turnout; in NZ, it's one of our worst results in 100 years (only 2011 and 2002 were worse).

So, why didn't New Zealanders vote?

Demographics be the first answer to try. Which group of New Zealanders didn't vote? Of course non-voters might have different hypothetical preferences to people who fit in similar demographic boxes, but who are voters. But it might give us some idea. Statistics NZ is likely to be collecting that kind of data. In the past, it's been less-educated, younger, and non-white ethnic groups that have less of a say.

Alternatively, we could ask people why they didn't vote. Statistics NZ did that last time around, and this is what they found:
  • 64% of non-voters had considered voting in this Election.
  • 43% of non-voters decided on Election Day that they would not vote.
  • 41% of non-voters put just a little thought into whether or not to vote, and 29% didn’t think about it at all.
  • The main overall reasons for not voting were that they had other commitments (14%) or work commitments (9%), could not be bothered voting (14%), couldn’t work out who to vote for (11%) and that their vote would not make a difference (8%).  
  • 33% of all non-voters agreed ‘I don’t trust politicians’ was an important factor (4 or 5 out of 5) on their not voting.  Other important factors were ‘it was obvious who would win so why bother’ (31%), and I’m just not interested in politics (29%).  Since 2008 there has been an increase in the proportion of non-voters saying ‘it was obvious who would win so why bother’ (from 19% to 31%).
A number of these reasons seem to relate to whether it's perceived there's a real choice voters can make. If:
  • the result seems predetermined
  • one side seems particularly appealing
  • the other side seems particularly unappealing
  • there doesn't seem to be much real difference between the candidates/parties
we might expect turnout to be lower.

Does this bear out across previous elections in New Zealand?

We can look at the margin between the two sides to see whether more people turn out to vote when there's a very close election, compared to when there's not much of a real choice.

The graph above shows the percentage turnout for each election between 1931 and 2014, excluding 1978 when data was not available. Elections with a National advantage are shown as a blue dot; elections with a Labour advantage are shown as a red dot. There does seem to be a significant trend apparent: the greater the margin between political parties, the lower the turnout (ρ[43]=-.41, p=0.033). So it seems like turnout has something to do with whether voters thought there was a genuine contest.

Does this effect seem to work on Labour supporters more than National supporters? Maybe National voters are habitual voters who reliably turn out every election, while left-wing voters only really come out if they can see a party worth supporting, a genuine choice, and a genuine chance of winning. We can take a look at the data above from a different angle:


The graph shows elections between 1931 and 2014, excluding 1978 where data wasn't available. National wins (those with “advantage” greater than 0, on the right side) are shown with a blue dot. Labour wins (those with “advantage” less than 0, on the left side) are shown with a red dot. It looks as if when turnout gets worse, National does significantly better in elections (r[43]=-.41, p=0.035).

So what does it mean? It seems like as the gap between the percentage of votes for each of the major parties increases, turnout gets lower. It's hard to say which direction the effect is in, but it does seem like voters for the losing side just doesn't turn out. Also, that effect might apply more when Labour's losing, because in general, National does better when turnout is low, while Labour does better when turnout is high.

If this pattern applied for the last election, where turnout was among the lowest ever, then the low turnout, and National's MMP 'landslide', is at least in part due to the lack of choice voters felt. Maybe it seemed like the outcome was inevitable. Or, voters didn't think Labour represented a real alternative – either because they weren't much different from National, or they didn't seem to be a better government than National, due to policy or leadership or some other reason.

If this election was generally like past elections, then low voter turnout, a landslide for National, and the lack of good alternatives are probably all linked.


Sources
http://www.elections.org.nz/events/past-events/general-elections-1853-2011-dates-and-turnout
http://www.elections.org.nz/news-media/preliminary-results-2014-general-election
Raw data and statistical analysis code is available on request.