New Zealand had the second highest rate of car ownership in 2012.

New Zealand families have the third-highest material living standard in the world, a local study has found.

Researchers at public policy research institute Motu used data from 800,000 households across 40 countries to create the new measure for wellbeing, which took into account homes that included a 15-year-old.

The measure is based on ownership of possessions such as books, internet connections, whiteware and cars, as well as the number of bedrooms and bathrooms in a house.

In 2012, New Zealand ranked just behind the United States and Canada, and ahead of Australia and all the Scandinavian countries.

Motu senior fellow Dr Arthur Grimes said the results should call into question the widespread negative impression of living standards in New Zealand compared with other developed countries.

"Our results show New Zealand is still a great place to bring up children, at least in material terms.

"Not only do we have wonderful natural amenities, but contrary to what GDP statistics tell us, most Kiwi families have a high standard of material wellbeing relative to our international peers."

Grimes said New Zealand's level of average material wellbeing in part reflected its high number of cars and bathrooms per household.

New Zealand had the second- and seventh-highest average possession rate for cars and numbers of bathrooms in 2012.

But the results also showed a lower level of bedrooms and study places per household in New Zealand.

New Zealand ranked 23rd by average number of bedrooms and 24th by the proportion of households with a quiet place for the student to study.

"This might suggest that New Zealand's material welfare is in jeopardy if further reductions in housing amenities per capita occur due to pressures in the Auckland housing market," Grimes said.

The report found the high standard of material wellbeing was accompanied by moderate levels of material inequality.

New Zealand ranked 20th of 40 countries in terms of inequality, with levels similar to those in the USA, Canada and Great Britain.

Australian households were not quite as wealthy as New Zealand ones but inequality in Australia was lower than that in New Zealand.

"Overall, these figures suggest we may need to reassess how we look at this country's economic performance," Grimes said.