Referendum facts and figures

Part A of the Referendum asked if we should keep the MMP system or change to an alternative.

57.8% of valid votes were in favour of keeping MMP. That compares well with the 53.9% in favour of MMP in the 1993 run-off referendum against FPP.

By far the strongest support in favour of MMP in 2011 came from the seven Maori electorates, ranging from 85.5% in Waiariki to 78.9% in Te Tai Tonga. That was closely followed by Mangere (76.7%). Urban, traditionally Labour-held seats tended to be the strongest supporters of MMP, after the Maori seats.

But support for MMP was also strong in some urban blue electorates. Hamilton East was 59.4% in favour of MMP, but was won by National on party vote (51.4%) and candidate vote (8,275 majority). Botany favoured MMP by 55.4% (slightly below the overall result), but National scored 61.1% party vote there, and the National candidate has a 10,741 majority.

By contrast, the strongest support for changing the voting system came from rural and traditionally National-held seats. Clutha-Southland topped the change vote with 55.4% in favour of change.

Ground-zero for MMP politics, the Epsom electorate, was marginally in favour of MMP (50.1% voting to keep it). In Ohariu, 62.0% voted to keep MMP, above the national average. So the pressure on those electorates has not turned their voters against MMP.

Part B of the referendum asked which of 4 alternative voting systems you would choose if there were a change of electoral system.

There is a compellingly strong statistical correlation (0.96) between the percentage of votes in favour of MMP in each electorate and the percentage of informal votes in Part B. Those in favour of MMP were clearly less likely to indicate a preference for any alternative – though some may have thought they weren’t supposed to. So, Waiariki voters returned 48.9% informal votes in Part B, but only 2.2% in Part A.

In Part B, 33.14% of votes nation-wide were informal, and this figure is higher than the percentage of votes in favour of the front-running alternative (FPP) which got 31.19%.

Let’s look, then, at the valid votes only for Part B. As a percentage of valid votes, 46.7% voted for FPP as the favoured alternative. The strongest support for FPP came from rural South Island electorates, beginning with Clutha-Southland (58.1%). The lowest support for FPP came from urban electorates, with no obvious bias towards either National or Labour strongholds. The lowest were Wellington Central (24.5%) and Auckland Central (32.3%). Epsom voters gave relatively low support for FPP (33.2% of valid votes).

While the Maori seats led the vote in favour of retaining MMP, for their valid votes in Part B the most popular alternative was FPP. All but one Maori seat gave higher rates of valid votes for FPP than the national average – but then they also had high rates of informal votes, in the 40s.

Supplementary Member (SM) ran second among the alternatives. It had been promoted by the ‘Vote for Change’ lobby-group with the support of Mr Key. It got 16.14% of all votes nation-wide, and 24.1% of valid votes. Looking only at the valid votes, the six electorates that returned the strongest support for SM were all blue-ribbon Auckland electorates, with Epsom at the top (35.9%). Maori and South Auckland electorates gave the lowest support for SM.

The strongest support for STV was in Wellington Central, with 37.9% of valid votes. Wellington Central was also the least in favour of FPP. Note that STV is used there in local body elections.

Preferential voting (PV) got the strongest support in the 10 Maori and South Auckland electorates, with Waiariki at the top again giving PV 23.4% of valid votes. But these electorates had high levels of informal votes (over 40%), and their valid votes for FPP were higher (45.7 to 51.6%) than for any other alternative. PV got the lowest vote overall.

Data source: Electoral Commission