I haven’t read through this new paper yet (pdf), but the authors and title make it self-recommending. Here is one bit taken from a quick perusal:
Figure 8 presents the distribution of the return on invested capital (ROIC) for publicly traded non-financial U.S. firms from 1965 through 2014, excluding good will (an intangible asset reflecting the excess of the price paid to acquire a company over the value of its net assets). This analysis excludes financial firms, where ROIC data is considerably more scarce. As the chart shows, the 90th percentile of the return on invested capital across firms has grown markedly since around the early 1990s. The 90/50 ratio—that is, the ratio of the 90th percentile of the distribution of capital returns to the median—has risen from under 3 to approximately 10. In addition, the dramatic returns on invested capital of roughly 100 percent apparent at the 90th percentile, and even 30 percent apparent at the 75th percentile, at the very least raise the question of whether they reflect economic rents.
Do read the whole thing, as will I. Here is a related Peter Orszag Bloomberg piece.