The United States has a variety of regulations to address the
economic harm resulting from monopoly power in an industry. This
includes the Sherman Act of 1890, the Clayton Act of 1914, and the
Federal Trade Commission Act of 1914.
These acts were aimed at restricting the formation of cartels and monopolies to protect consumers and ensure competition.
The article The Oligopoly Problem
argued that oligopolies fall through the cracks of these regulations
and leave consumers unprotected from harmful business practices where
industries are highly concentrated.