The Economic Complexity of the Western Roman Empire

I am one of those people who think about the Roman Empire daily – possibly out of my worrying addiction to Crusader Kings III and similar games. I also spent some time working on estimating economic complexity , a neat measure that can be used to explain economic development trajectories. One fateful day, I was attending a presentation by the excellent Petra Heřmánková when the two thoughts collided in my head like protons in the Large Hadron Collider. Like a data science version of Young Frankenstein, I suddenly realized that we could calculate the Economic Complexity of the Roman Empire and yelled in the middle of her presentation: “It can be done!” 1