Overseas students are still the largest single group contributing to net overseas migration, but large numbers of New Zealanders escaping a sluggish economy and backpackers arriving en masse are keeping numbers far higher than government forecasts.

While the number of migrant arrivals decreased over the past year by 10 per cent to 667,000, and the number of people leaving increased by 8 per cent to 221,000, net migration was still 445,600. That is 50,600 more than the federal government’s forecast of 395,000, according to Australian Bureau of Statistics data.