More than half of New Zealand's total net wealth is owned by Kiwis aged 55 and above, the New Zealand Herald reports.

The news is based on Roy Morgan's "state of the nation" report, which says the 55-plus group has increased its share of net wealth from 43 per cent in 2002 to 52 per cent last year, as their population also increased in the same period.

From 19.5 per cent in 2002, the 55-and-above population has risen to 24.7 per cent in 2011.

The wealthy adults gained their fortune mostly from house price boom in the last ten years, with the value of their own homes accounting for 56 per cent of their wealth a decade ago, and 70 per cent last year.

Roy Morgan's report showed 85 per cent of the said group is comprised of homeowners.

In addition to the house price boom, an increase in work hours yielded higher gain for the 55-and-above group.

Forty-eight per cent of the said group is now receiving regular income. The figure was a steep jump from 35 per cent in 2002, making the group account for nearly a quarter of New Zealand's total workforce.

Roy Morgan chief executive Michele Levine concluded the increasing number of older people in New Zealand should be seen as an asset for the country, rather than a burden.