"Up until the GFC [global financial crisis, 2007] we had the highest level of skill shortages of any country in the OECD. We're now number 4, but tracking upwards again.
"I don't want to leave you with a doom and gloom scenario," Prof Spoonley told conference delegates, "but when I talk to regional councils and communities about this, there is denial."
TVNZ is about to screen a series about people fleeing from Auckland because of traffic congestion, house prices and the pace of life, but the reality is far more people are moving to the City of Sails.
Auckland is already home to about a third of the nation's people; within a decade that is predicted to be 40 per cent. And that's where the lion's share of jobs and migrants will go as well.
This is highly unusual. Paris and London have 18-20 per cent of their country's populations. No other city in the world other than Dublin has anything like a third of their country's population, let alone 40 per cent of it.
"There is nothing much that is going to stop Auckland's growth, unless a volcano blows," he said.
Two-thirds of our regions are experiencing population stagnation, or decline.
Current population growth - one of the highest in the OECD at just over 2 per cent - is largely coming from nett migration gains.
Our birth rates are barely enough to replace deaths; we are likely to dip below sub-fertility soon. Australia is well below sub-fertility now, and the likes of Japan and Germany have been there for some time "and are having very significant issues".
Chancellor Angela Merkel allowing more than a million migrants across Germany's borders in recent years might have had a humanitarian aspect as well "but it was also about having enough workers for Germany's factories".
Taranaki is our first region to have more people over 65 than aged 0-14, but it won't be the last. Our baby boomers grew at a time when the over-65s were 8-10 per cent of the population; "regions should now anticipate rates of 25-35 per cent".
Dr Spoonley said when rural areas bleed young people and workers, services start to dwindle or close. School rolls suffer, GPs can't be attracted to work there.
"We're going to have to anticipate [and plan for] future labour supply. We're very bad at this," he said.
Prof Spoonley said he has challenged various sectors - including agriculture - to identify their worker and skill needs 5-10 years out. They struggle to do it five years out, and some can't even estimate three years ahead.
The internet was supposed to be an answer. People don't have to be in the cities when they can work via computer, remotely.
"It hasn't happened. [Young people and the skilled] like the boot camps, they like the lattes, they like going down the road to talk to co-workers. That's an international story, not just a New Zealand one."
However, Prof Spoonley added that good broadband was a crucial factor in rural towns holding on to businesses and workers.
There was no shortage of questions from the floor.
Can the Overseas Investment Office and other government institutions help maintain investment in the regions?
Prof Spoonley answered by saying most countries in Europe and many in other parts of the globe have robust regional development programmes. The NZ government "could, and should, do more.
"You can do things to push [activity out into the regions]. In the UK [for example], vehicle licensing is headquartered in Hull."
Someone else asked how job vacancies in the regions might be filled when the roles are not on the skills shortage list.
Prof Spoonley said regions might need to develop their own immigration recruitment and retention policy, and push central government to allow it.
"Canterbury has it, with the rebuild. We've got to get off our butts and say to the minister 'our area has skills shortages, we want to see these roles on the skilled shortages list, and by the way, we want a say on the recruitment and approval of immigrants'.
"If you take immigration out, all of our positive economic stories almost evaporate. GDP growth, minus he immigration factor, goes back to 0.5 per cent.
"Immigration is a really good news story, with a lot of positive economic impacts and I don't think the Government wants that tap turned off."
Towns such as Gore and Ashburton were in good shape, largely because of immigration. Half of the new dairy workers in Southland last year were Filipino. School classes are bulging with Filipino pupils, a Filipino food store has opened, and three Filipino priests have been brought in.
"In some places, if your rely on people who look like me [older, Pakeha] ... we're not going to be the workers on your farms or in your processing plants."