No, Monopoly Has Not Grown - KEY TAKEAWAYS

Take an industry wherein the C4 ratio in the base year is 8 percent (each of the top 4 firms has an average of 2 percent of the market). [...] In other words, did the concentrated get even more concentrated? Figure 3 presents this relationship, with the y-axis showing the percentage-point change in the C4 from 2002 to 2017, and the x-axis presenting the level of C4 in 2002. [...] In fact, the correlation between the C4 ratio and the change in PPI was actually negative (-0.31), meaning the more concentrated the industry, the lower the price increase. [...] To assess this, ITIF combined aggregated profit data from the Corporation Complete Reports from the Internal Revenue Service with the Census C4 data at 3-digit NAICs code, as this was the level of aggregation in the IRS data set.45 ITIF was able to get data on profits and concentrations for 80 industries.46 ITIF used the measure of the ratio of net income over total receipts for profits. [...] These books almost all start with a description of an idealized world before the 1980s when corporations were supposedly much smaller and everyone else much better off, and then a host of economic problems since then are all laid at the feet of the rise of so-called monopolies and the rise of a new corrupt school of antitrust, enabled by craven antitrust scholars in the pocket of big companies.