University of Otago politics professor Janine Hayward says Palmerston North voters are understanding how to use STV.

Most people who voted in the Palmerston North City Council elections in October showed they understood how to use their single transferable vote.

The STV system invites electors to rank as many or as few candidates as they like.

Figures released to Stuff show 16 per cent of voters chose to rank 15 candidates, the number of seats at the council table, down slightly from 17.2 per cent at the previous election in 2013.

Just under 4 per cent gave their vote to just one candidate, then a surge of 6.92 per cent ranked the whole 27.

READ MORE:

* Wellington, what just happened? The capital city's election, Justin Lester v Andy Foster, explained

* Decision to stick with single transferable voting could be challenged

* Transferring votes made a difference for at least one city councillor

Half of voters stopped ranking candidates once they got to nine, with six the most common stage where people stopped.

In the mayoral election, nearly half of all voters ranked only their top choice, with just under 17 per cent ranking their second choice, and 18.4 per cent ranking all six candidates.

Just under 4 per cent did not vote for any of the mayoral candidates and just under 1 per cent did not make a single choice for council.

Otago University politics professor Janine Hayward said the decrease in the number of people ranking 15 candidates for the council indicated voters were getting the hang of STV.

Mayor Grant Smith and some other commentators have blamed STV for being too complicated, compared with the first past the post (FPP) system, and contributing to falling voter turnout.

MURRAY WILSON/STUFF Palmerston North voters used single transferable votes to elect the current city council.

The proportion of eligible electors who voted in the city council election was 37.32 per cent.

Hayward has rejected that reasoning and said the patterns of voting showed people knew what they were doing with STV.

"What is interesting about your result is that almost 50 per cent of voters cast only one preference for the mayor, despite the fact that their voting in the council election indicates that most people understand the idea of ranking.

"So this might indicate that people felt only one candidate was worth supporting at all."

It was also interesting that so many people ranked all of the mayoral candidates, when the pattern for council candidates indicated they understood they did not have to.

"I think this is all very encouraging evidence that Palmerston North voters are getting the hang of the system and using it effectively."