Also, there are now concerns infrastructure in Auckland and Christchurch, the two most favoured destinations for Kiwis arriving home and new migrants, will be strained, requiring greater contributions to such things as roads, public transport and other community facilities.
Wages are unlikely to rise and unemployment is unlikely to fall as returning Kiwis take skilled jobs those now seeking employment cannot fill.
There is no incentive to train New Zealanders for skilled roles as those returning often have the skills needed to move straight back into the workforce.
However, employers seeking skilled workers get their shortages filled, allowing them to increase productivity, and those moving back often bring families, adding to the tax take and domestic spending.
The main concern will be retaining those skilled workers once their contracts or projects finish.
Statistics New Zealand figures showed annual net migration was sitting at 47,700 in October, a record net gain. The previous peak in May 2003 was 42,500.
Even if the monthly pace of net migration peaks in October 2014, the annual rate of net migration would not reach a peak until early next year.
The ASB was expecting a peak annual inflow of about 55,000 in February next year, although it was revising its forecasts given the relentless strength of monthly migration inflows, economist Christina Leung said.
BNZ senior economist Craig Ebert said normally, a migration impetus of that size would have the central bank quaking in its boots, over the inflationary consequences it would bring.
''While this is still something to think about very carefully - especially with the Reserve Bank running with easy official cash rate policy for the meantime - the composition of the migration flow remains important to understand, for some of its non-inflationary features.''
Most of the increase in migrant arrivals continued to reflect those on student visas - especially, now, from India - and those on work visas.
That was different from arrivals for residency purposes, which tended to put more pressure, directly, on the home-buying market.
And the work-visa component suggested a quicker streamlining into jobs, boosting supply potential as much as it did demand.
Even those on student visas were potentially available for local work, he said.
The other detail to note was while Auckland (up 21,800) and Canterbury (up 5700) experienced a good chunk of the overall 47,500 migrant gain over the year to October 2014, it did not seem out of line with typical weights and/or trends.
Nearly all other regions experienced migrant gains over the past 12 months.
As with the construction story, the immigration boom is not just the case for Auckland and Canterbury, Mr Ebert said.
Statistics NZ figures showed Waikato had a net gain of 1500, Otago had a net gain of 1300 and Wellington gained 1200 migrants.
Migration in Auckland, Canterbury and Otago increased mainly because of more arrivals.
Fewer departures from Waikato and Wellington drove increases in those regions.
Ms Leung said given the historical relationship between net migration, house prices and consumer spending, the Reserve Bank was sensitive to net migration developments.
Net migration had proved stronger than expected in the past six months and the central bank remained mindful of the housing-market related risks to financial and price stability.
The Reserve Bank was expected to keep the OCR on hold at 3.5% until September next year, she said.
''Strong net migration and impact on the economy are key reasons why the Reserve Bank maintains a tightening bias despite low inflation outcomes.
"We expect the Reserve Bank will keep its high-LVR lending restrictions in place until they can be confident it has peaked and the housing market is not at risk of reigniting should the restrictions be lifted.''
At a glance
Biggest changes in October year:
• Migrants from India 9500, China 7200, the United Kingdom 5300,the Philippines 3400.
• Student visas up 6900.
• New Zealand and Australian citizens up 3300.
• Work visas up 3200.
