The Greggs-Pret Index: Machine Learning Determines North-South Divide in England

For the uninitiated, Pret is where you buy an avocado salmon salad, and Greggs is where you buy a sausage roll.

Unfortunately, this metric puts Cornwall in "The North", so instead, the authors propose the more effective Waitrose vs Morrisons Index as an alternative. Waitrose is a supermarket where you can buy both quail eggs and ostrich eggs. Morrisons stocks neither.