Detta är intressant: Företagens marginaler i USA har ökat över tiden:

We document the evolution of market power based on firm-level data for the U.S. economy since 1955. We measure both markups and profitability. In 1980, aggregate markups start to rise from 21% above marginal cost to 61% now. The increase is driven mainly by the upper tail of the markup distribution: the upper percentiles have increased sharply. Quite strikingly, the median is unchanged.

Har hittills bara läst abstract, men en spontan fundering är: Hur mycket av detta är en Apple-effekt?

Källa: De Loecker, Jan, Jan Eeckhout, and Gabriel Unger. 2020. "The Rise of Market Power and the Macroeconomic Implications*." The Quarterly Journal of Economics 135(2): 561–644. https://doi.org/10.1093/qje/qjz041.