There’s a lot of analysis about “why Labour did not win”. (Short answer: it was heavily overdetermined.) But this is about just one reason that is not why Labour did not win, one thing that almost certainly made no difference to the result: hoardings.
There’s various theories about Labour’s hoardings, ranging from the true – Vote Positive was a weird choice for a message – to the somewhat kooky – apparently we should have plastered David Cunliffe’s face over everything, as if voters might have somehow forgotten he was leader – to the utterly crazy – the claim that Auckland MPs were hiding party vote hoardings on back streets. These theories, of course, are always delivered with complete certainty.
But there’s a fundamental problem with these arguments: hoardings have very little effect on the outcome of elections. Hardboiled American political hacks have a stock phrase for this: “signs don’t vote”. It’s not quite fair to say they don’t do anything – seeing a neighbour’s fence with a candidate’s face on it does matter, because it’s an endorsement from someone in your community, someone who’s part of your broader social milieu. But a large billboard at the roadside? It just doesn’t make much difference. As an Auckland friend of mine sarcastically puts it, “I always make voting decisions based on what corflute on the street tells me”.
There’s some academic research to back this up*, and smart American practice is shifting this way. So, overall, if your theory of Labour’s loss relies on poor hoarding design or display, it is not a load bearing structure.
* Which I’m too lazy to look up right now, sorry.