An interesting trend

Phil Lyth has done an interesting analysis of votes cast so far in the local body elections, and discovered that small South Island towns are twice as likely to vote as cities in the North Island [PDF].

The Councils with the best voter turnouts so far are:

49.0% Chatham Islands Council
40.1% Buller District Council
38.0% Westland District Council
37.5% Ashburton District Council
37.9% Central Otago District Council
37.0% Waimate District Council

While the lowest turnouts are in:

20.9% Palmerston North City Council
19.8% Hutt City Council
19.6% Hamilton City Council
17.6% Wellington City Council
16.9% Porirua City Council
16.8% Waikato District Council

A quarter of Aucklanders, 24.8%, have voted for the new Supercouncil.

That's a fairly impressive difference, and I'm wondering what the reasons for it are. Smaller, tighter communities? Does local government matter more in rural areas? Do they just care more? I'm sure there's a sociology thesis in finding the reasons for the difference.