A Treasury research report has found concern about household debt levels is overdone.

Trends in household debt between 2002 and 2007 have raised some questions about whether borrowing is "excessive," researchers Katherine Henderson and Grant Scobie say in a Treasury working paper published on Christmas Eve.

The average net worth of New Zealand households fell $14,500 in the September quarter, on top of a $17,000 decline in the previous quarter, according to a new report.

The December Spicers’ Household Savings Indicators report shows average household net worth is nearly $40,000 lower than a year earlier, at $355,516 per household.

The average New Zealand household lost $6700 or 1.7% of their net assets in the June 2008 quarter, the Spicers Household Saving Indicators report shows.

The June dip follows a similar loss of 1.6% in the March quarter and 0.5% in the December quarter. But Spicers chief executive Gordon Noble-Campbell says most households are still in a strong financial position because these declines come after high gains in recent years.

“Only some belt tightening [will be] required to get through the current uncertainty.”