The Finance Minister has no doubt about our enthusiasm for KiwiSaver.

A report, released by the IRD at the end of last week, says KiwiSaver isn't as good as it's cracked up to be in terms of saving and maximising investment.

But Bill English says that's just an economist's view.

He says it's had a much bigger impact on people's understanding about saving than was ever anticipated.

"Back in 2007 when it started, we thought it would be about 700,000. In fact there are 2.5 million in Kiwisaver.