The Greyquake, and why NZ First, and maybe National, should be plucky

Projected Voter Turnout Rates.png

Greyquake, Superquake, Pensionquake, none of those names are as catchy as Youthquake, but unless there's a dramatic turnaround in voting behaviour by younger voters, this election is set to be dominated by those with, at the very least, a sprinkling of salt and pepper in their hair.

You can see in the above graph the difference between 2014's turnout and my projections for 2017's turnout. Assuming all things remain the same from the Electoral Commissions 12 September update of enrolment data, there's going to be a noticeable shift from the youngest half of voters to the oldest half of around 4.69 points.

That might not seem like much in the scheme of things, but in an MMP environment it's a massive shift. The difference between whether a party can feasibly form a government could be decided by as little as half a percent, so to have a shift of several times that towards an older demographic in the pool of electors will undoubtedly make a different.

As I wrote earlier today, the way that enrolments are tracking suggests that for all the efforts to encourage younger voters to participate in the election, nothing is changing. What is happening those is as New Zealand's population ages, the demographic of those enrolled to vote is sharply changing in favour of those aged 55 and over. The top half of enrolled voters goes down to around the 53 mark by my maths so you could stretch it a little further if you liked.

It's also why I suspect NZ First have historically done better on election day than they have in the polls. As far as I'm aware (and please correct me if I'm wrong!) both Colmar Brunton and Reid Research both weight their poll samples to reflect the general population. However the general population, or even the number of eligible voters isn't necessarily the best way to weight your polls.

Instead your polls should be weighted to reflect the voter turnout rates from the previous election (or even averaged off the past two or three just to hedge your bets a little). With older voters making up a far larger block of actual voters, their voices suddenly matter a whole lot more come election time than they do in the general population.

Projected changes in age cohorts.png

The above graph illustrates this change even better. You can see the massive shift away from youth voters towards those aged 55 and over (though as a mentioned earlier I suspect the tipping point may be around 53 or so). These are voters who probably own houses, probably still have mortgages they're paying off, their kids have probably left home or are about to, and they're planning for retirement.

What does this mean come Election Day? Assuming that voter turnout is similar to 2014 and enrolment rates don't change markedly, it means that NZ First is going to continue on its trend of performing better in the ballot than they do in polls, and a similar effect might help National as they've been focused on eating up some of NZ First's lunch too, especially in regional New Zealand.

It'll be interesting to compare these projects with the actual statistics from the election once they're released.