The Wall Street Journal ran an article, “Behind Rising Inequality: More Unequal Companies”. with some interesting charts.
Since 1990 the return on capital of a 90th percentile U.S. company has spiked from its historical average in the 20-30% range up to about 100%. Within-firm employee pay distribution hasn’t changed that much but if you work for a winner (market-leading or monopoly) company you probably get paid very handsomely compared to people who work for a loser (exposed to competition) company.
Some excerpts:
everyone at the top companies, from the lowest to highest paid, pulled away from the pack, and everyone at the bottom companies languished.
The economists did find that the top 0.2% of earners in firms with more than 10,000 employees did significantly better than their fellow workers. But for the other 99.8%, the expanding pay gap can be explained by where they work.
Some companies may so dominate their market that they can extract profits over and above what a purely competitive landscape would allow; economists call these excess profits “rents.” Employees at those companies then share in those rents.