The global economy is slowing down. A couple of the big emerging-market economies that drove much of the growth during the past 15 years have hit a wall, and the question of the moment is whether the biggest of them, China, is in real trouble too. Commodity prices are tanking. Trade volumes are down. The Baltic Dry Index of shipping costs, which rebounded from a record low earlier this year, is falling again.
These are all characteristic of a cyclical downturn. And this is a cyclical downturn — oil prices will rise again someday. So will emerging-market stock and bond prices.
But there could also be something else afoot. We could be seeing early signs of longer-term changes in the global economy — changes that could be enormously positive, but also have the potential to upend a lot about how the world works today.