KiwiSaver fees remain high, the returns are mixed and an increasing concentration of bank-run schemes are a concern for the competitiveness of the market, a report carried out by Treasury has found.
The Government department has released a review on KiwiSaver fund manager market dynamics and allocation of assets.
It predicts the value of KiwiSaver assets will grow to $70 billion within five years - more than double the $28 billion which research firm Morningstar valued the industry at as of June 30.
KiwiSaver now makes up a growing share of household financial assets in New Zealand but Treasury has a number of concerns.
"Overall, the market appears to be competitive, however, with a growing level of concentration."