Unlike the cities of the Randstad and Rhine-Ruhr and those of the Greater South East of England, the cities of the North of England do not harness the benefits of agglomeration. The result is that they punch well below their weight, which acts as a drag on the economic performance of the North as a whole.

This means that if the Northern Powerhouse initiative is to improve the performance of the North of England, it must focus on improving the performance of its cities and city regions. This should principally be done through increasing the density of businesses in city centres, improving the skills of residents and improving transport links within city regions.

Much focus to date has been given to improving rail links between cities. Bringing cities closer together is likely to be important, but the positive impacts of doing this will only be realised if the cities themselves have strong economies. The allure of a grand projet should not divert attention from improving the places it is designed to link, particularly when it comes to transport within the city regions and skills across the North.

Both the Northern Powerhouse and devolution deals offer an opportunity to improve the performance of northern cities, making them the engines not just of the northern but the national economy once again. Doing this will ensure that the North improves its productivity in the coming decades, rather than underperforming as it has in previous ones.