Many people are worried about increasing levels of economic concentration in United States industries. As a result, they call for expanding the interventionist reach of antitrust law. That would mean encouraging the Justice Department to reject more mergers and bring suits against more companies alleged to have monopoly power.
One difficulty with this approach is that it is difficult to determine whether a company possesses monopoly power, let alone figure out whether a merger will result in more monopoly power rather than invigorate competition. Moreover, attacks on monopoly discourage businesses from trying to obtain monopolies, an effort that itself brings innovation and benefits for consumers.
Three policies would decrease concentration far better than expanding antitrust law: making our trade freer, cutting back on regulation, and getting out of the way of efficient capital markets. Together, these policies would make the monopolization provisions in antitrust law much less needed.
Free Trade: The most powerful competition against domestic firms with market power can come from abroad.