The average US public firm today is three times larger, even after correcting for inflation, than it was two decades ago.47As a number of studies have shown, US industries are becoming more dominated by a few large firms today – they are becoming more concentrated, in econ- speak.48 For example, between 1982 and 2012, retail trade saw the share of the top four firms double from 15 per cent to 30 per cent. In the critical sector of information technology, media, and communications, the Economist magazine found the top four firms now accounted for nearly 50 per cent of the revenue.49
Concentration of revenue in sectors
