An economic think tank says some struggling regions are in danger of falling even further behind.

A study of regional economies by The Institute of Economic Research found Auckland and Taranaki have performed well, but Northland and Hawke's Bay have not.

The Institute said the national economy is performing well, but that doesn't mean all regions are experiencing more jobs or higher incomes.

Its principal economist, Shamubeel Eaqub, said large urban centres such as Auckland, or dairy regions such as Southland, have done well, but Northland, Hawke's Bay and Whanganui have not.

Mr Eaqub said poorly performing provinces may struggle to survive in the long term and an ageing population and increasing urbanisation will make it even harder for these provinces to generate higher incomes and alleviate rising poverty.

Bur he warned politicians first need to understand why some places are falling behind, before acting.

"Understanding before action, it's easy to call for action and have solutions in search of a problem. We first have to understand why is it that some regions are falling behind and then tailor any interventions we need to make."