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.