The Australian Government says more and more Australians are moving to New Zealand because of the lower income tax rate.
Its treasurer, Joe Hockey, wants to lower the top tax bracket of 49 cents in the dollar to compete with New Zealand's 33 cents in the dollar.
Massey University demographer Professor Paul Spoonley said the net inflow from Australia is a significant turnaround from 2012, when 54,000 people crossed the Tasman in the opposite direction.
He said the strength of the economy was the main attraction, though higher-paid Australians might be lured here by lower tax rates.
Mr Hockey said in the past 12 months more Australians moved to New Zealand than vice versa.
He said 10 years from now almost half of Australian taxpayers will be paying up to 49 cents in the dollar on their income.