Results have now been released from the 26 November referendum on the New Zealand electoral system. The referendum consisted of two parts. In Part A, voters were asked “Should New Zealand keep the Mixed Member Proportional (MMP) voting system?” In Part B, voters were asked “If New Zealand were to change to another voting system, which voting system would you choose?”, with a menu of four choices for the change option: First Past the Post, Preferential Voting, Single Transferable Vote, and Supplementary Member.

In Part A, 57.77% voted to keep MMP. This, of course, renders Part B moot. Nonetheless, comparing across the two parts is interesting. While 2,194,774 valid votes were cast in Part A, there were only 1,509,157 in Part B. Informal votes, defined as “when the voter has not clearly indicated the option for which they wish to vote” were just 62,469 in Part A, but a whopping 748,086 in Part B.

If we can assume that essentially all of the 926,819 voters who voted to change from MMP would have indicated a preference over the four change options, then it would seem that approximately half of the “keep MMP” voters did not bother to select an alternative system.¹ One wonders how many of these voters simply were confident MMP would be kept, so it was not worth taking a stand on (and bothering to learn about) the alternatives, and how many did not understand that they could choose an alternative even while voting for the current system.

Rationally, any MMP supporter should prefer STV over all the others offered, given that STV is the only proportional system among the alternatives.² Yet STV obtained only 252,503 votes (16.7% of valid votes in Part B), placing third among the alternatives. If just under two thirds of the informal vote in Part B had been cast by MMP voters indicating STV as their fallback, then STV would have beaten out FPTP in Part B.

A referendum in 2014 between the two proportional systems would have been interesting, had “change” won in Part A. Instead, however, the old FPTP system dominated Part B. It was probably expectation of precisely such a result that generated such indifference over Part B, as few could imagine FPTP ever beating MMP in a second referendum were one to have been triggered.

The results in Part B, with percentages based on valid votes only, were:

48.66% FPTP
24.14% SM (i.e. MMM)
16.72% STV
12.47% PV (AV)

1. 685,617 is the difference between the valid votes cast in the two parts; this is equivalent to 54% of the 1,267,955 votes for keeping MMP. [↩]
2. Unless what someone really likes about MMP is the single-seat districts, yet would not want FPTP again. I suppose such a voter might rank Preferential Voting–that is, the Alternative Vote–as second best. And some could argue for “SM” (MMM) as being most similar to MMP, though it is far worse than any option other than FPTP for supporters of parties other than the big two. [↩]