Australians are leaving NSW faster than any other state.
New data from the Bureau of Statistics shows 42,990 NSW residents moved interstate in the six months to September, offset by the arrival of 39,180 new residents from other states.
The net emigration of 2810 was Australia's largest, far more than South Australia which lost 1310 citizens and suffered the biggest net emigration as a proportion of its population.
Victoria and Queensland both enjoyed net immigration, gaining a net 3880 and 3190 residents from other states.
The most popular destination for NSW residents is Queensland, followed by Victoria, the Australian Capital Territory and Western Australia. Emigrants to NSW are most likely to come from Queensland, Victoria and the Australian Capital Territory.
The net leakage of NSW residents to other states was more than offset by births and the arrival of a net 27,440 new residents from overseas. NSW receives almost one-third of Australia's arrivals.
"It is something we see in many global cities," said University of Queensland demographer Martin Bell. "There's clearly a connection between overseas migration and internal emigration. But it's nothing like what it was in the 1980s and 1990s. Unemployment and house prices are evening up. Internal migration to Queensland is a fraction of what it was. It used to be 1000 a week."
The bureau's projections have Sydney's population almost doubling to 8.12 million by 2056. Melbourne's population will grow faster, boosted by immigration from other states to reach 8.16 million. Perth would become Australia's third biggest city with 5.1 million, eclipsing Brisbane with 4.5 million. Adelaide would have 1.9 million, Canberra 700,000, Hobart 268,000 and Darwin 216,000.
NSW would remain Australia's biggest state with a population of 11.1 million. Victoria would have 9.9 million, Queensland 8.8 million, and Western Australia 6 million.
The projections are consistent with those in the intergenerational report.
Professor Bell said if the Bureau of Statistics went ahead with its plan to axe the 2016 census Australia would have no reliable information on small area populations until 2023, when the data from the 2021 census becomes available.
"At a time of very high immigration we would be without the one source of information we need to plan appropriately," he said.