Sometimes the most important economic events announce themselves with huge front-page headlines, stock market collapses and frantic intervention by government officials.
Other times, a hard-to-explain confluence of forces has enormous economic implications, yet comes and goes without most people even being aware of it.
In 2015 and 2016, the United States experienced the second type of event.
There was a sharp slowdown in business investment, caused by an interrelated weakening in emerging markets, a drop in the price of oil and other commodities, and a run-up in the value of the dollar.