Economist Shamubeel Eaqub says his analogy about centres such as Whangarei becoming "zombie towns" was meant as a wake-up call, not an insult.
Mr Eaqub ruffled provincial feathers last month by saying that on an international ranking Auckland, Wellington and Canterbury were comparable to France, Finland and Saudi Arabia respectively, and Northland was like Timor-Leste.
Regions such as Northland and Whanganui were declining economically and population-wise to past their "tipping point", and on track to becoming zombie towns, the New Zealand Institute of Economic Research's (NZIER) principal economist said on TV3 programme, The Nation, when he was discussing his new book, Growing Apart, Regional Prosperity in New Zealand.
Mr Eaqub spoke to the Northern Advocate on Friday while he was in Whangarei to address Northland local government representatives.
Without change, New Zealand was headed toward further division into thriving centres and impoverished regions, he said.
"The world has changed fast and favoured urban growth. Change is possible and necessary or [places like Northland] are destined to decline and stagnate."
If there are any hard solutions for Northland he was not sharing them with the media.
However, it is no secret that rates and other reforms are major issues facing local governments, he said.
Regarding his Timor-Leste and zombie comments, Mr Eaqub said he was happy to be the centre of provocation if it helped spur regional political, business and community leaders into action.
While Northland was in danger of catastrophic decline, just down the road Auckland was growing in all ways. Auckland provided huge opportunities for Northland's growth and future planning, not least in helping provide infrastructure for that metropolis, Mr Eaqub said.
There were significant other opportunities for Northland "in the pipeline" but making them happen needed "real commitment, communication and community buy-in".
Community leaders, local and central governments needed to be focused on "enabling" change and growth, Mr Eaqub said.
"It's important to get local government into a role where it's an usher, not a bouncer," he said.