In The Law of Civilization and Decay (1895), Brooks Adams made a dubious but interesting claim, and a prediction. He argued that centralized capital (wealth accumulated between ruling families) seems to have gradually moved in one direction from Sumer, to the dynasties of Egypt, followed by Greece, the Italian peninsula, various parts of Germany, then Britain. Then, as it teetered between London and New York in 1900, Adams predicted that American capital would overshadow the British Empire within the first half of the 20th century. This proved correct, and since then a further Westwards shift in capital has occurred from New York to Texas/Western USA.

I can spot some obvious objections to the theory. First it should be said that Adams had absolutely no explanation behind why this occurs and was merely spotting a trend. The reason he ignores Asian centers of capital like Ayutthaya and Beijing is that he is describing the movement of a specific zone of capital that has shifted among a particular ruling class from the Middle-East, across the Mediterranean, to Western Europe and eventually North America.

All this in mind, there are notable setbacks, like how the collapse of Western Rome spurred an Eastward power shift from Italy to Anatolia, or the seeming arbitrary direction of the power shifts in 1600-1900 multipolar Europe.

I think it's likely Adams was seeing a pattern where there wasn't any, but when you consider the most well-known empires from the Middle-East to the Atlantic, the way they seem to shift in one direction through time is too interesting not to talk about. Is there anything more to this?