Does a monopolist aim to maximize profit, or simply to hide from the antitrust laws?
AT&T's absolute monopoly in the switched long-distance telephone market ended in 1976 when MCI rolled out its Execunet service. Twenty years later economists still question whether AT&T can influence the market price of long-distance services.
Recent empirical studies are split on the question, sometimes finding AT&T has considerable market power, and sometimes finding it has none.
It appears that economists studying the long-distance industry may be misinterpreting the historical record.