It is disturbing, therefore, to learn this condition of citizenship will exclude about two-thirds of the New Zealanders who have gone to Australia to live.
The "Bondi bludger" may be a myth, but clearly most of the expats must be in low-paid, unskilled jobs. These are not the sort of jobs any country needs immigrants to fill.
The same may be true of many of the better paid jobs being done by Kiwis in Australia, which is why the deal just done is a significant concession by Mr Turnbull.
Australia, like most developed countries, including New Zealand, requires immigrants to have a skill in short supply before they gain admission.
The single exception has been New Zealanders, who have long enjoyed a freedom to go to Australia without particular skills to offer, or a job lined up.
Australians have the same access to this country. Free movement between the two, which dates from colonial times, has been taken for granted and still is, despite welfare restrictions introduced by Australia 15 years ago.
Those restrictions followed an unsuccessful bid by the Howard Government to have New Zealand reimburse the Australian Treasury for welfare paid to expats.
Helen Clark rightly refused but, wishing to retain the right of New Zealanders to live and work across the Tasman, could do nothing to stop the withdrawal of some benefits.
No New Zealander moving across the Tasman since 2001 ought to have been under any delusion that they would have all the rights of Australian citizenship, yet many have been aggrieved to discover benefits not available when they or their children needed them.
Their older children's predicament became particularly anomalous - having grown up in Australia they were excluded from tertiary education grants.
Mr Turnbull announced an end to that anomaly when he was here in October. Now he has agreed to give all expats already living and earning a decent wage in Australia a special path to citizenship.
It is a privileged path - avoiding the skills criteria that applicants from other countries face - and it applies only to those already there.
Having won this much special treatment, Mr Key says his Government will press for the deal to be extended to future migrants from New Zealand.
He should also do his utmost to ensure that henceforth, New Zealanders move across the Tasman with their eyes open. They will not be able to take advantage of the deal he had done for those already there.
Those migrating in future, and their New Zealand-born children, will be in the same position expats post-2001 were in until last weekend. They should not take anything for granted.
Debate on this article is now closed.