The United Nations Population Fund Pacific says migration from the Pacific has more than doubled since the 1950's.
Its Fiji-based representative, Najib Assifi, says by the mid 1990's migration had gained momentum with the numbers reaching 400,000.
Mr Assifi, who is in New Zealand for the launch of population reports, says population growth became almost nil in Samoa and Tonga and was negative in the Cook Islands, Niue and Tokelau during some periods.
He says people can be enticed back home, but that has to be done by governments
"If the Pacific Island countries, also relax their policies, invite more of their nationals who migrated abroad come back even if it's for a short period of time I think eventually more people will come back for family reunions, but also for starting small businesses in their own country."