How the polls did last year

I only noticed this chart on Friday, but Andrew at Grumpolie looked at how the polls and polls of polls did, compared to the election result.

The Herald Digipoll was best overall. Of the poll of polls, the methodology I used did fairly well.

Not on the chart is how iPredict did. It was very accurate in 2011, but in 2014 was well out with a total error of 12.3%.

Overall the public polls under-estimated support for National and NZ First, were slightly too high for Labour and way too high for the Greens.

Andrew also made the point:

The landline bias/non-coverage issue is a red herring – the polls that came closest only call landlines. It’s just one of many potential sources of error that pollster’s need to consider. Here’s another post about this, if anyone is interested in finding out why it’s not such a big deal.