However, Tower Investments CEO Sam Stubbs believes arguments against compulsion are flawed and it would help the country be "considerably" better off.

According to its 2010 Review of Retirement Income Policy, the Retirement Commission said evidence to the effectiveness of compulsory saving is mixed and it "does not support changes to make KiwiSaver compulsory."

Lee said with KiwiSaver requiring employees to actively opt-out, he believes the scheme has struck the right balance between being voluntary or compulsory.

He also said compulsion wouldn't necessarily raise the amount of money saved - also an issue highlighted by the Commission - and that it should be "very much a last resort."

Also in common with the Commission Lee  said there would be a danger compulsion could detrimentally affect the current NZS - "a very efficient system" - as cash would have to be diverted from other savings and investments towards KiwiSaver.

Lee also said he is "yet to be convinced we have a savings issue."

He believes the real issue is how current retirement savings are invested and spent, and that growing the overall economy would provide a more significant boost to retirement provision.

The Commission did recommend raising the retirement age from 65 to 67 by 2033 - a move ruled out by both National and Labour - but failed to back making KiwiSaver, or any other type of savings, compulsory.

In stating its opposition to compulsion the Review cited concerns administration and compliance costs would rise. Compulsion would also limit the choices of individuals to save through a particular means and "would not allow for differences in circumstances, preferences or stages of life. It might also open the door to undermining the universality of NZS."

Sam Stubbs takes the opposing view to Lee.

He believes the arguments against compulsion are fundamentally flawed as "the debate around compulsion uses academic models."

He believes the models used "assume perfect human behavior" with regard to financial management, which he regards as unrealistic.

Also he believes the current system of allowing an opt-out actually discriminates against the less well off as they have less spare capacity financially for savings.

Looking at the Australian model in particular, Stubbs said he had no reason not to believe countries that adopt compulsory savings won't be "considerably better off in 20 years time."

The Review also raised the concern that compulsion, while changing the composition of saving, might not necessarily change the overall amount saved.

"Despite its generous incentives and automatic enrolment of new employees, KiwiSaver has currently achieved less than 40% coverage among the eligible population. While introducing compulsion would raise participation, would it increase the amount saved?"

The Review did make several recommendations surrounding KiwiSaver however.

It suggests KiwiSaver default funds should continue to be based on products with a conservative risk profile and that providers be encouraged to "provide members with information to help them to make a more active choice of investment."

A standardised approach to the calculation of KiwiSaver fees and performance is also recommended, a measure the Ministry of Economic Development (MED) is currently seeking submissions on.

The Commission also recommended the Retirement Commissioner's 2013 Review of Retirement Income Policy include "a thorough assessment of KiwiSaver, including the emerging pattern of withdrawals and reinvestments by people aged over 65."

It also recommends Statistics New Zealand include KiwiSaver questions in appropriate household surveys "in order that the impact and effectiveness of KiwiSaver can be assessed and informed decisions made about adjustments to the scheme beyond 2012/13."