2017/04/24: Economists are very worried about the decline in labor’s share of U.S. national income. One reason they’re concerned is because when less of an economy’s wealth flows to workers, it exacerbates inequality and increases the risk of social instability. But another reason is that this trend throws a wrench in economists’ models. For decades, macroeconomic models assumed that labor and capital took home roughly constant portions of output -- labor got just a bit less than two-thirds of the pie, capital slightly more than one-third. Nowadays it’s more like 60-40.
There are four main theories, each of which falls apart under scrutiny.