March 18, 2015 9:00am by David Farrar

Which Green candidate has been best at growing the party vote?

Danyl McL has blogged:

My friend James – last seen on this blog demagoguing it up at the Te Aro Meet the Candidates event – has entered the Green Party leadership contest. I’ll be helping him with his campaign so will possibly not be the most impartial commentator on the race.

The data-based argument for James’ leadership is basically the chart below. He wasn’t an MP when he ran in Wellington Central last year yet more people there voted Green than any other electorate in the country.

A commenter has responded:

With all due respect to James, that’s a very poor starting point for a data-based argument. Wellington Central is choc-full of green votes because the demographics of the seat heavily lean to young urban liberals. If the Greens didn’t make 30% in that seat, then we’d all be calling it a poor result.

I agree that saying Shaw should be leader because his seat gets the most party votes is a poor argument.

What would be a better analysis is how much extra party vote has a candidate got in a seat, when they have stood there.

Let’s look at 2011 and 2014. First of all 2011.

The median increase for the Greens that year was 4.2%. Some selected seats:

Akl Ctl (Roche) +7.3%
Wgtn Ctl (Shaw) +7.1%
Rongotai (Norman) +7.2%
Ohariu (Hughes) +5.3%
Chch Ctl +5.1%
Northcote (Tava) +4.2%
Hague (WCT) +3.3%

So Shaw got the largest party vote increase of the four candidates in 2011, and Hague the smallest. However Shaw’s increase was around the same as the neighbouring Rongotai and Auckland Central.

Now for 2014 where the median change in party vote was dropping -0.2%: