It’s not often I agree with a government minister, but Greg Clark has got the Centre for Cities bang to rights (The MJ, 20 January).

As an economic migrant from Manchester in the 1970s, I am well aware of the differences in economic opportunity in parts of the UK. However, where I agree with the minister is that the current methodology used by the Centre of Cities is actually painting a worse picture than needed of the local economies of the North and Midlands.

To understand this I need to introduce you to Primary Urban Areas (PUAs). These were devised by the Department for Communities and Local Government in 2006 as a measure of the built-up area of cities.

The first thing to recognise is that a lot has happened since, including a world financial crisis and the abolition of Regional Development Agencies. On a more positive note, it has also seen movement towards city regions and combined authorities in many major conurbations.