New Zealand has one of the highest proportion of expatriates in the world and about one in five indicate they have little intention of returning, according to a survey of Kiwis living abroad.

The survey run by Kea (the Kiwi Expat Association) indicates that a significant number of New Zealanders had made the move overseas for good.

Kea chief executive Ross McConnell said that didn't have to be seen in a negative light.

"It is plain that many expats simply aren't coming home, but they can still have a role in New Zealand's future."

Mr McConnell said there were many talented, well-connected New Zealanders who showed a deep commitment to the country.

"Expats are prepared to crawl over hot coals for their country ... This is an opportunity we have not yet made the most of."

Their goodwill meant we could keep them engaged and contributing to life here, he said.

More than 18,000 people who identified themselves as New Zealanders responded to the survey. They were living in 155 countries. One fifth had been overseas for a decade or more.

One third had citizenship of a second country and more than half had spouses or partners who were not New Zealand citizens.

More than 40 per cent of the respondents said they were living overseas for economic reasons such as career prospects. They were mostly aged between 25 and 40 years.

Mr McConnell said New Zealand's high proportion of expats (about 16 per cent of the population) was second only to Ireland (about 24 per cent).

In contrast, only 2 per cent of Australians are living outside the Lucky Country.

Mr McConnell viewed the high number of New Zealanders living overseas as a largely untapped resource.

He said the "brain drain" debate was counter-productive.

"We will still wander. OE is very much part of our DNA ... We should think how that is a competitive advantage."

The survey showed that one-third of the expats earned more than NZ$100,000, which would put them in the top 3 per cent of income earners in New Zealand.

Over 80 per cent had tertiary qualifications, compared to 35 per cent of the New Zealand population.

Mr McConnell said the young and wealthy expat community had a lot to offer.

"They don't have to be here to contribute ... They can open doors and opportunities in markets where we need to do business in future."

More than half the expats maintained some sort of economic connection with New Zealand, and over one-third indicated they would stay away more than five years before returning.

Dr Paul Callister, a senior research fellow at Victoria University, said there was a lot of discussion as to how many New Zealanders lived overseas. Estimates ranged from 400,000 to one million.

Dr Callister said a high proportion were skilled people but that was countered by the number of people who lived in NZ but were born overseas, creating a "brain swap" scenario. "It's like a railway station - people coming in one end and rushing out the other."

Dr Callister said expats could be useful for encouraging migration to New Zealand.

Kea chairman Stephen Tindall said harnessing the skills and potential of Kiwis overseas could be "incredibly powerful".

COMING OR NOT

* 50 per cent of expats say they will, or probably will, return to New Zealand.

* Nearly 20 per cent say they are unlikely to or won't return.

* 33 per cent are undecided.

* 50 per cent come home for lifestyle reasons.