An  argument pensions should come later - to make superannuation sustainable

Investment consulting firm Mercer and the CFA Institute have ranked New Zealand's retirement income system 17th out of 52 countries.

They took in the financial impact of our ageing population, and KiwiSaver's voluntary nature - and relatively low contribution rates.

Mercer NZ CEO, Anna Scott, says the Government should revisit our pension age of 65, and think about superannuation, long-term.

She says the pool of money needs to provide the best level of care for people, when they get there.