"There was one thing which bothered me, and I hope it bothers you too, the points from the 20th century are all positioned in or above Scandinavia which seems unlikely to be the center of anything in the world. You can find the reason for that in the caption on the McKinsey webpage. Their report looks at the Earth as a sphere and finds the economic center of gravity which falls somewhere inside the sphere. To plot it on the map, they take a radius through the center of gravity and intersect it with the surface."
That's fair, but looking at the earth as anything but a sphere is unlikely to produce more useful results. One possibility is that a center-of-gravity of wealth just isn't all that useful a measure of economic history: A major historical shift could end up being represented by a dot budging a few hundred miles in the middle of nowhere.
From the article:
"There was one thing which bothered me, and I hope it bothers you too, the points from the 20th century are all positioned in or above Scandinavia which seems unlikely to be the center of anything in the world. You can find the reason for that in the caption on the McKinsey webpage. Their report looks at the Earth as a sphere and finds the economic center of gravity which falls somewhere inside the sphere. To plot it on the map, they take a radius through the center of gravity and intersect it with the surface."