Conscious parallelism is a term used in antitrust law to describe price-fixing between competitors in an oligopoly that occurs without an actual spoken agreement between the parties. Instead, one competitor will take the lead in raising prices. The others will then follow suit, raising their prices by the same amount, with the unspoken mutual understanding that all will reap greater profits from the higher prices so long as none attempts to undercut the others. Antitrust or competition laws, legislate against trade practices that undermine competitiveness or are considered to be unfair. ... Law (a loanword from Old Norse lag), in politics and jurisprudence, is a set of rules or norms of conduct which mandate, proscribe or permit specified relationships among people and organizations, provide methods for ensuring the impartial treatment of such people, and provide punishments for those who do not follow... An oligopoly is a market form in which a market is dominated by a small number of sellers (oligopolists). ...

This practice, like most anticompetitive practices, is harmful to consumers who can be forced to pay monopoly prices for goods that should be selling for only a little more than the cost of production. Nevertheless, it is very hard to prosecute because it occurs without producing any proof of collusion between the competitors.

The term has also been used to describe industrywide assumption of terms other than price. For example, all competitors in an industry might make only long-term leases of products such as heavy machinery, leaving lessors with no opportunity to make a short-term lease of that product from any competitor.