A new policy aimed at attracting more migrants to Northland would achieve nothing, warned the Government's lead economic adviser.
According to documents released under the Official Information Act, Treasury told Finance Minister Bill English on July 16 the new Government measures aimed at getting migrants to the regions were unlikely to help regional development.
The measures went to Cabinet for approval on July 20 and the increased bonus points on residency requests was announced on July 26.
Under the revised scheme, skilled workers who take jobs in the regions or set up businesses there will get more points for their residency applications.
Pressed on how many migrants might be attracted by the policy change, Prime Minister John Key said: "We can't tell you exactly up front. It will make it certainly more attractive, I don't know the exact numbers. I do know there is capacity in the regions, that there is demand in the regions, and we've seen migration flows be very successful there."
However, the July Treasury briefing to Mr English had warned the policy changes were unlikely to have an impact on regional development.
Whangarei District Council's economic development manager Peter Gleeson said migrants were already keen to come to the district and were filling important roles.
The Treasury briefing said most migrants did not go to non-urban areas.
Of the Skilled Migrant Category migrants who had jobs or a job offer in 2013/2014, 47 per cent were based in Auckland, 18 per cent were in Canterbury, 11 per cent in Wellington and 5 per cent in Waikato. There was currently no mechanism to ensure migrants stayed in regions even if they claimed the bonus points, the briefing said.
"Once a migrant has a residence class visa they are free to move around the country as they choose."
The small number of extra bonus points was unlikely to push over the line many migrants who weren't currently meeting requirements and a far greater amount of points could be claimed for meeting other criteria such as age, education, employment or capital investment.
Treasury team leader Hayden Fenwick noted the briefing was drafted in relation to an early version of the migration proposals. At that time, the Government proposed increasing points for settling in the regions from 10 to 20 under the Skilled Migrant Category.
Mr Gleeson said the district was attracting lots of high-quality, skilful migrants, who council wanted to retain in the district.
"We have a skill shortage in our district, therefore migrants play a very important role filling roles we need satisfying," he said.
Nearly all were coming for specific jobs such as nurses, doctors, information and communications technology specialists, engineers and welders, or as highly skilled workers.
"The work provides social contact, and people often get to know others in the community," said Mr Gleeson.