How often do Maori swap rolls?

Parliament recently changed the law so that NZers of Maori descent can change between the General and Maori rolls at any stage, except for the three months before a local or general election (or by-election). The law used to only it allow it after each census, so that the electoral populations would be equal.

The law change is not one I was keen on, as my worry is you could get tactical enrolments where people swap from a general to a Maori roll or vice-versa based on which seat is most competitive.

I was interested in how often NZers of Maori descent have swapped between rolls, so I asked the Electoral Commission. They have data for the 2006, 2013 and 2018 Maori options. They calculated:

• 724,424 have not swapped at all (91.6%)
• 61,881 swapped once (7.8%)
• 4,427 swapped twice (0.6%)
• 144 swapped three times (0.02%)

I found this data reassuring that in the past there appears to be few people who have been tactically swapping. I would define anyone who swapped twice or three times as probably doing it for tactical reasons. Fewer than 5,000 over the country is unlikely to make a big difference.

It is of course possible that now the law has changed, we may get more roll swapping. I will follow future data with interest. But for now, it is fair to say that my concerns do not appear to be likely to evenuate.