KiwiSaver provider Milford Asset Management says the retirement scheme shouldn't be made compulsory.

Milford's executive director and Weekend Herald columnist Brian Gaynor says he disagrees with calls from KiwiSaver founder and former Finance Minister Sir Michael Cullen to make the scheme mandatory.

"We think it'll make fund managers a bit complacent," Gaynor said.

"If everyone is compelled to contribute, it takes a lot of the competitive onus away from fund managers. Having a voluntary scheme keeps us more on our toes, having to perform better."

Advertisement
Advertise with NZME.

While many more people signed up to scheme than originally expected, Gaynor said only 10 per cent of people's funds are invested in the New Zealand sharemarket.

"One of the problems is that the New Zealand sharemarket is too small and it doesn't offer the kind of investment opportunities that people want. For example, it doesn't have financial services companies except for Heartland Bank whereas in Australia the four banks are all worth more than the total value of the New Zealand sharemarket, so the NZX just doesn't have the opportunities for KiwiSaver investors."