The north-south divide: Researchers try to settle debate using Greggs and Pret locations

While we can all agree that London is very much in the south of England, those of us brought to the capital from beyond zone six will have often faced one unanswerable question: are we technically northern?

Now a “tongue-in-cheek analysis” aims to answer the question of where the north of England officially begins once and for all, with a little help from artificial intelligence.

In carrying out their study, researchers took a look at two food-to-go chains: northern powerhouse Greggs, and southern mainstay Pret. The former was founded in Tyneside in 1951, with the latter opening its first shop in Hampstead in 1984.

The paper — titled “The Greggs-Pret Index: a Machine Learning analysis of consumer habits as a metric for the socio-economic North-South divide in England” — adapts an algorithm usually used to study nuclear reactions to assess the prominence of the two shops across England, and thus reveal where the south gives way to the north. The fact that there are more Greggs stores than Prets is taken into account.

“The food we eat is a very good indicator of whether someone is northern or southern,” said Dr Robin Smith, a physicist at Sheffield Hallam University who led the study. “Greggs is very popular in the north, where people do seem to prefer a steak bake.”

“We are fascinated by the north-south divide, so it is good to have a way of working out where it starts.” In particular, the abstract of the “tongue-in-cheek analysis” states that it “aims to highlight more serious factors highlighting the North-South divide, such as life expectancy, education, and poverty.”

So where does the North begin?

The North-South dividing line as determined by the Artificial Neural Network regression analysis of Greggs and Pret locations. The heatmap denotes the calculated 'Northern-ness' and 'Southern-ness' as a function of location. The black line is a separating contour line. (ResearchGate)

The ‘optimal’ north/south line isn’t a straight one. It essentially slices off the southeast of England, starting off from just above Poole and shooting upwards towards Skegness via the Watford Gap — often earmarked as the turning point — before dipping down to absorb the north coast of Norfolk.

The North-South dividing line as determined by the Greggs and Pret shops analysed using the SVM. Greggs shops are plotted in blue, and Pret in red. (ResearchGate)

Curiously, that means that Cornwall — the most southern county in the UK — is for the purposes of this analysis, northern. But that’s chiefly down to a lack of data: the county contains just two Greggs stores, and is yet to experience the simple delights of a Pret Chicken Ceasar and Bacon Baguette.

While a secondary analysis — using Waitrose (established: Acton, 1904) and Morrisons (established: Bradford, 1899) — produced different results, it still includes the Watford Gap, suggesting it remains as good a marker as any.